1 /*
2 * Copyright 2000-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_ciTypeFlow.cpp.incl"
27
28 // ciTypeFlow::JsrSet
29 //
30 // A JsrSet represents some set of JsrRecords. This class
31 // is used to record a set of all jsr routines which we permit
32 // execution to return (ret) from.
33 //
34 // During abstract interpretation, JsrSets are used to determine
35 // whether two paths which reach a given block are unique, and
36 // should be cloned apart, or are compatible, and should merge
37 // together.
38
39 // ------------------------------------------------------------------
40 // ciTypeFlow::JsrSet::JsrSet
41 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
42 if (arena != NULL) {
43 // Allocate growable array in Arena.
44 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
45 } else {
46 // Allocate growable array in current ResourceArea.
47 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
48 }
49 }
50
51 // ------------------------------------------------------------------
52 // ciTypeFlow::JsrSet::copy_into
53 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
54 int len = size();
55 jsrs->_set->clear();
56 for (int i = 0; i < len; i++) {
57 jsrs->_set->append(_set->at(i));
58 }
59 }
60
61 // ------------------------------------------------------------------
62 // ciTypeFlow::JsrSet::is_compatible_with
63 //
64 // !!!! MISGIVINGS ABOUT THIS... disregard
65 //
66 // Is this JsrSet compatible with some other JsrSet?
67 //
68 // In set-theoretic terms, a JsrSet can be viewed as a partial function
69 // from entry addresses to return addresses. Two JsrSets A and B are
70 // compatible iff
71 //
72 // For any x,
73 // A(x) defined and B(x) defined implies A(x) == B(x)
74 //
75 // Less formally, two JsrSets are compatible when they have identical
76 // return addresses for any entry addresses they share in common.
77 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
78 // Walk through both sets in parallel. If the same entry address
79 // appears in both sets, then the return address must match for
80 // the sets to be compatible.
81 int size1 = size();
82 int size2 = other->size();
83
84 // Special case. If nothing is on the jsr stack, then there can
85 // be no ret.
86 if (size2 == 0) {
87 return true;
88 } else if (size1 != size2) {
89 return false;
90 } else {
91 for (int i = 0; i < size1; i++) {
92 JsrRecord* record1 = record_at(i);
93 JsrRecord* record2 = other->record_at(i);
94 if (record1->entry_address() != record2->entry_address() ||
95 record1->return_address() != record2->return_address()) {
96 return false;
97 }
98 }
99 return true;
100 }
101
102 #if 0
103 int pos1 = 0;
104 int pos2 = 0;
105 int size1 = size();
106 int size2 = other->size();
107 while (pos1 < size1 && pos2 < size2) {
108 JsrRecord* record1 = record_at(pos1);
109 JsrRecord* record2 = other->record_at(pos2);
110 int entry1 = record1->entry_address();
111 int entry2 = record2->entry_address();
112 if (entry1 < entry2) {
113 pos1++;
114 } else if (entry1 > entry2) {
115 pos2++;
116 } else {
117 if (record1->return_address() == record2->return_address()) {
118 pos1++;
119 pos2++;
120 } else {
121 // These two JsrSets are incompatible.
122 return false;
123 }
124 }
125 }
126 // The two JsrSets agree.
127 return true;
128 #endif
129 }
130
131 // ------------------------------------------------------------------
132 // ciTypeFlow::JsrSet::insert_jsr_record
133 //
134 // Insert the given JsrRecord into the JsrSet, maintaining the order
135 // of the set and replacing any element with the same entry address.
136 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
137 int len = size();
138 int entry = record->entry_address();
139 int pos = 0;
140 for ( ; pos < len; pos++) {
141 JsrRecord* current = record_at(pos);
142 if (entry == current->entry_address()) {
143 // Stomp over this entry.
144 _set->at_put(pos, record);
145 assert(size() == len, "must be same size");
146 return;
147 } else if (entry < current->entry_address()) {
148 break;
149 }
150 }
151
152 // Insert the record into the list.
153 JsrRecord* swap = record;
154 JsrRecord* temp = NULL;
155 for ( ; pos < len; pos++) {
156 temp = _set->at(pos);
157 _set->at_put(pos, swap);
158 swap = temp;
159 }
160 _set->append(swap);
161 assert(size() == len+1, "must be larger");
162 }
163
164 // ------------------------------------------------------------------
165 // ciTypeFlow::JsrSet::remove_jsr_record
166 //
167 // Remove the JsrRecord with the given return address from the JsrSet.
168 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
169 int len = size();
170 for (int i = 0; i < len; i++) {
171 if (record_at(i)->return_address() == return_address) {
172 // We have found the proper entry. Remove it from the
173 // JsrSet and exit.
174 for (int j = i+1; j < len ; j++) {
175 _set->at_put(j-1, _set->at(j));
176 }
177 _set->trunc_to(len-1);
178 assert(size() == len-1, "must be smaller");
179 return;
180 }
181 }
182 assert(false, "verify: returning from invalid subroutine");
183 }
184
185 // ------------------------------------------------------------------
186 // ciTypeFlow::JsrSet::apply_control
187 //
188 // Apply the effect of a control-flow bytecode on the JsrSet. The
189 // only bytecodes that modify the JsrSet are jsr and ret.
190 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
191 ciBytecodeStream* str,
192 ciTypeFlow::StateVector* state) {
193 Bytecodes::Code code = str->cur_bc();
194 if (code == Bytecodes::_jsr) {
195 JsrRecord* record =
196 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
197 insert_jsr_record(record);
198 } else if (code == Bytecodes::_jsr_w) {
199 JsrRecord* record =
200 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
201 insert_jsr_record(record);
202 } else if (code == Bytecodes::_ret) {
203 Cell local = state->local(str->get_index());
204 ciType* return_address = state->type_at(local);
205 assert(return_address->is_return_address(), "verify: wrong type");
206 if (size() == 0) {
207 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
208 // This can happen when a loop is inside a finally clause (4614060).
209 analyzer->record_failure("OSR in finally clause");
210 return;
211 }
212 remove_jsr_record(return_address->as_return_address()->bci());
213 }
214 }
215
216 #ifndef PRODUCT
217 // ------------------------------------------------------------------
218 // ciTypeFlow::JsrSet::print_on
219 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
220 st->print("{ ");
221 int num_elements = size();
222 if (num_elements > 0) {
223 int i = 0;
224 for( ; i < num_elements - 1; i++) {
225 _set->at(i)->print_on(st);
226 st->print(", ");
227 }
228 _set->at(i)->print_on(st);
229 st->print(" ");
230 }
231 st->print("}");
232 }
233 #endif
234
235 // ciTypeFlow::StateVector
236 //
237 // A StateVector summarizes the type information at some point in
238 // the program.
239
240 // ------------------------------------------------------------------
241 // ciTypeFlow::StateVector::type_meet
242 //
243 // Meet two types.
244 //
245 // The semi-lattice of types use by this analysis are modeled on those
246 // of the verifier. The lattice is as follows:
247 //
248 // top_type() >= all non-extremal types >= bottom_type
249 // and
250 // Every primitive type is comparable only with itself. The meet of
251 // reference types is determined by their kind: instance class,
252 // interface, or array class. The meet of two types of the same
253 // kind is their least common ancestor. The meet of two types of
254 // different kinds is always java.lang.Object.
255 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
256 assert(t1 != t2, "checked in caller");
257 if (t1->equals(top_type())) {
258 return t2;
259 } else if (t2->equals(top_type())) {
260 return t1;
261 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
262 // Special case null_type. null_type meet any reference type T
263 // is T. null_type meet null_type is null_type.
264 if (t1->equals(null_type())) {
265 if (!t2->is_primitive_type() || t2->equals(null_type())) {
266 return t2;
267 }
268 } else if (t2->equals(null_type())) {
269 if (!t1->is_primitive_type()) {
270 return t1;
271 }
272 }
273
274 // At least one of the two types is a non-top primitive type.
275 // The other type is not equal to it. Fall to bottom.
276 return bottom_type();
277 } else {
278 // Both types are non-top non-primitive types. That is,
279 // both types are either instanceKlasses or arrayKlasses.
280 ciKlass* object_klass = analyzer->env()->Object_klass();
281 ciKlass* k1 = t1->as_klass();
282 ciKlass* k2 = t2->as_klass();
283 if (k1->equals(object_klass) || k2->equals(object_klass)) {
284 return object_klass;
285 } else if (!k1->is_loaded() || !k2->is_loaded()) {
286 // Unloaded classes fall to java.lang.Object at a merge.
287 return object_klass;
288 } else if (k1->is_interface() != k2->is_interface()) {
289 // When an interface meets a non-interface, we get Object;
290 // This is what the verifier does.
291 return object_klass;
292 } else if (k1->is_array_klass() || k2->is_array_klass()) {
293 // When an array meets a non-array, we get Object.
294 // When objArray meets typeArray, we also get Object.
295 // And when typeArray meets different typeArray, we again get Object.
296 // But when objArray meets objArray, we look carefully at element types.
297 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
298 // Meet the element types, then construct the corresponding array type.
299 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
300 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
301 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
302 // Do an easy shortcut if one type is a super of the other.
303 if (elem == elem1) {
304 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
305 return k1;
306 } else if (elem == elem2) {
307 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
308 return k2;
309 } else {
310 return ciObjArrayKlass::make(elem);
311 }
312 } else {
313 return object_klass;
314 }
315 } else {
316 // Must be two plain old instance klasses.
317 assert(k1->is_instance_klass(), "previous cases handle non-instances");
318 assert(k2->is_instance_klass(), "previous cases handle non-instances");
319 return k1->least_common_ancestor(k2);
320 }
321 }
322 }
323
324
325 // ------------------------------------------------------------------
326 // ciTypeFlow::StateVector::StateVector
327 //
328 // Build a new state vector
329 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
330 _outer = analyzer;
331 _stack_size = -1;
332 _monitor_count = -1;
333 // Allocate the _types array
334 int max_cells = analyzer->max_cells();
335 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
336 for (int i=0; i<max_cells; i++) {
337 _types[i] = top_type();
338 }
339 _trap_bci = -1;
340 _trap_index = 0;
341 _def_locals.clear();
342 }
343
344
345 // ------------------------------------------------------------------
346 // ciTypeFlow::get_start_state
347 //
348 // Set this vector to the method entry state.
349 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
350 StateVector* state = new StateVector(this);
351 if (is_osr_flow()) {
352 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
353 if (non_osr_flow->failing()) {
354 record_failure(non_osr_flow->failure_reason());
355 return NULL;
356 }
357 JsrSet* jsrs = new JsrSet(NULL, 16);
358 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
359 if (non_osr_block == NULL) {
360 record_failure("cannot reach OSR point");
361 return NULL;
362 }
363 // load up the non-OSR state at this point
364 non_osr_block->copy_state_into(state);
365 int non_osr_start = non_osr_block->start();
366 if (non_osr_start != start_bci()) {
367 // must flow forward from it
368 if (CITraceTypeFlow) {
369 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
370 }
371 Block* block = block_at(non_osr_start, jsrs);
372 assert(block->limit() == start_bci(), "must flow forward to start");
373 flow_block(block, state, jsrs);
374 }
375 return state;
376 // Note: The code below would be an incorrect for an OSR flow,
377 // even if it were possible for an OSR entry point to be at bci zero.
378 }
379 // "Push" the method signature into the first few locals.
380 state->set_stack_size(-max_locals());
381 if (!method()->is_static()) {
382 state->push(method()->holder());
383 assert(state->tos() == state->local(0), "");
384 }
385 for (ciSignatureStream str(method()->signature());
386 !str.at_return_type();
387 str.next()) {
388 state->push_translate(str.type());
389 }
390 // Set the rest of the locals to bottom.
391 Cell cell = state->next_cell(state->tos());
392 state->set_stack_size(0);
393 int limit = state->limit_cell();
394 for (; cell < limit; cell = state->next_cell(cell)) {
395 state->set_type_at(cell, state->bottom_type());
396 }
397 // Lock an object, if necessary.
398 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
399 return state;
400 }
401
402 // ------------------------------------------------------------------
403 // ciTypeFlow::StateVector::copy_into
404 //
405 // Copy our value into some other StateVector
406 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
407 const {
408 copy->set_stack_size(stack_size());
409 copy->set_monitor_count(monitor_count());
410 Cell limit = limit_cell();
411 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
412 copy->set_type_at(c, type_at(c));
413 }
414 }
415
416 // ------------------------------------------------------------------
417 // ciTypeFlow::StateVector::meet
418 //
419 // Meets this StateVector with another, destructively modifying this
420 // one. Returns true if any modification takes place.
421 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
422 if (monitor_count() == -1) {
423 set_monitor_count(incoming->monitor_count());
424 }
425 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
426
427 if (stack_size() == -1) {
428 set_stack_size(incoming->stack_size());
429 Cell limit = limit_cell();
430 #ifdef ASSERT
431 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
432 assert(type_at(c) == top_type(), "");
433 } }
434 #endif
435 // Make a simple copy of the incoming state.
436 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
437 set_type_at(c, incoming->type_at(c));
438 }
439 return true; // it is always different the first time
440 }
441 #ifdef ASSERT
442 if (stack_size() != incoming->stack_size()) {
443 _outer->method()->print_codes();
444 tty->print_cr("!!!! Stack size conflict");
445 tty->print_cr("Current state:");
446 print_on(tty);
447 tty->print_cr("Incoming state:");
448 ((StateVector*)incoming)->print_on(tty);
449 }
450 #endif
451 assert(stack_size() == incoming->stack_size(), "sanity");
452
453 bool different = false;
454 Cell limit = limit_cell();
455 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
456 ciType* t1 = type_at(c);
457 ciType* t2 = incoming->type_at(c);
458 if (!t1->equals(t2)) {
459 ciType* new_type = type_meet(t1, t2);
460 if (!t1->equals(new_type)) {
461 set_type_at(c, new_type);
462 different = true;
463 }
464 }
465 }
466 return different;
467 }
468
469 // ------------------------------------------------------------------
470 // ciTypeFlow::StateVector::meet_exception
471 //
472 // Meets this StateVector with another, destructively modifying this
473 // one. The incoming state is coming via an exception. Returns true
474 // if any modification takes place.
475 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
476 const ciTypeFlow::StateVector* incoming) {
477 if (monitor_count() == -1) {
478 set_monitor_count(incoming->monitor_count());
479 }
480 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
481
482 if (stack_size() == -1) {
483 set_stack_size(1);
484 }
485
486 assert(stack_size() == 1, "must have one-element stack");
487
488 bool different = false;
489
490 // Meet locals from incoming array.
491 Cell limit = local(_outer->max_locals()-1);
492 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
493 ciType* t1 = type_at(c);
494 ciType* t2 = incoming->type_at(c);
495 if (!t1->equals(t2)) {
496 ciType* new_type = type_meet(t1, t2);
497 if (!t1->equals(new_type)) {
498 set_type_at(c, new_type);
499 different = true;
500 }
501 }
502 }
503
504 // Handle stack separately. When an exception occurs, the
505 // only stack entry is the exception instance.
506 ciType* tos_type = type_at_tos();
507 if (!tos_type->equals(exc)) {
508 ciType* new_type = type_meet(tos_type, exc);
509 if (!tos_type->equals(new_type)) {
510 set_type_at_tos(new_type);
511 different = true;
512 }
513 }
514
515 return different;
516 }
517
518 // ------------------------------------------------------------------
519 // ciTypeFlow::StateVector::push_translate
520 void ciTypeFlow::StateVector::push_translate(ciType* type) {
521 BasicType basic_type = type->basic_type();
522 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
523 basic_type == T_BYTE || basic_type == T_SHORT) {
524 push_int();
525 } else {
526 push(type);
527 if (type->is_two_word()) {
528 push(half_type(type));
529 }
530 }
531 }
532
533 // ------------------------------------------------------------------
534 // ciTypeFlow::StateVector::do_aaload
535 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
536 pop_int();
537 ciObjArrayKlass* array_klass = pop_objArray();
538 if (array_klass == NULL) {
539 // Did aaload on a null reference; push a null and ignore the exception.
540 // This instruction will never continue normally. All we have to do
541 // is report a value that will meet correctly with any downstream
542 // reference types on paths that will truly be executed. This null type
543 // meets with any reference type to yield that same reference type.
544 // (The compiler will generate an unconditional exception here.)
545 push(null_type());
546 return;
547 }
548 if (!array_klass->is_loaded()) {
549 // Only fails for some -Xcomp runs
550 trap(str, array_klass,
551 Deoptimization::make_trap_request
552 (Deoptimization::Reason_unloaded,
553 Deoptimization::Action_reinterpret));
554 return;
555 }
556 ciKlass* element_klass = array_klass->element_klass();
557 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
558 Untested("unloaded array element class in ciTypeFlow");
559 trap(str, element_klass,
560 Deoptimization::make_trap_request
561 (Deoptimization::Reason_unloaded,
562 Deoptimization::Action_reinterpret));
563 } else {
564 push_object(element_klass);
565 }
566 }
567
568
569 // ------------------------------------------------------------------
570 // ciTypeFlow::StateVector::do_checkcast
571 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
572 bool will_link;
573 ciKlass* klass = str->get_klass(will_link);
574 if (!will_link) {
575 // VM's interpreter will not load 'klass' if object is NULL.
576 // Type flow after this block may still be needed in two situations:
577 // 1) C2 uses do_null_assert() and continues compilation for later blocks
578 // 2) C2 does an OSR compile in a later block (see bug 4778368).
579 pop_object();
580 do_null_assert(klass);
581 } else {
582 pop_object();
583 push_object(klass);
584 }
585 }
586
587 // ------------------------------------------------------------------
588 // ciTypeFlow::StateVector::do_getfield
589 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
590 // could add assert here for type of object.
591 pop_object();
592 do_getstatic(str);
593 }
594
595 // ------------------------------------------------------------------
596 // ciTypeFlow::StateVector::do_getstatic
597 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
598 bool will_link;
599 ciField* field = str->get_field(will_link);
600 if (!will_link) {
601 trap(str, field->holder(), str->get_field_holder_index());
602 } else {
603 ciType* field_type = field->type();
604 if (!field_type->is_loaded()) {
605 // Normally, we need the field's type to be loaded if we are to
606 // do anything interesting with its value.
607 // We used to do this: trap(str, str->get_field_signature_index());
608 //
609 // There is one good reason not to trap here. Execution can
610 // get past this "getfield" or "getstatic" if the value of
611 // the field is null. As long as the value is null, the class
612 // does not need to be loaded! The compiler must assume that
613 // the value of the unloaded class reference is null; if the code
614 // ever sees a non-null value, loading has occurred.
615 //
616 // This actually happens often enough to be annoying. If the
617 // compiler throws an uncommon trap at this bytecode, you can
618 // get an endless loop of recompilations, when all the code
619 // needs to do is load a series of null values. Also, a trap
620 // here can make an OSR entry point unreachable, triggering the
621 // assert on non_osr_block in ciTypeFlow::get_start_state.
622 // (See bug 4379915.)
623 do_null_assert(field_type->as_klass());
624 } else {
625 push_translate(field_type);
626 }
627 }
628 }
629
630 // ------------------------------------------------------------------
631 // ciTypeFlow::StateVector::do_invoke
632 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
633 bool has_receiver) {
634 bool will_link;
635 ciMethod* method = str->get_method(will_link);
636 if (!will_link) {
637 // We weren't able to find the method.
638 ciKlass* unloaded_holder = method->holder();
639 trap(str, unloaded_holder, str->get_method_holder_index());
640 } else {
641 ciSignature* signature = method->signature();
642 ciSignatureStream sigstr(signature);
643 int arg_size = signature->size();
644 int stack_base = stack_size() - arg_size;
645 int i = 0;
646 for( ; !sigstr.at_return_type(); sigstr.next()) {
647 ciType* type = sigstr.type();
648 ciType* stack_type = type_at(stack(stack_base + i++));
649 // Do I want to check this type?
650 // assert(stack_type->is_subtype_of(type), "bad type for field value");
651 if (type->is_two_word()) {
652 ciType* stack_type2 = type_at(stack(stack_base + i++));
653 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
654 }
655 }
656 assert(arg_size == i, "must match");
657 for (int j = 0; j < arg_size; j++) {
658 pop();
659 }
660 if (has_receiver) {
661 // Check this?
662 pop_object();
663 }
664 assert(!sigstr.is_done(), "must have return type");
665 ciType* return_type = sigstr.type();
666 if (!return_type->is_void()) {
667 if (!return_type->is_loaded()) {
668 // As in do_getstatic(), generally speaking, we need the return type to
669 // be loaded if we are to do anything interesting with its value.
670 // We used to do this: trap(str, str->get_method_signature_index());
671 //
672 // We do not trap here since execution can get past this invoke if
673 // the return value is null. As long as the value is null, the class
674 // does not need to be loaded! The compiler must assume that
675 // the value of the unloaded class reference is null; if the code
676 // ever sees a non-null value, loading has occurred.
677 //
678 // See do_getstatic() for similar explanation, as well as bug 4684993.
679 do_null_assert(return_type->as_klass());
680 } else {
681 push_translate(return_type);
682 }
683 }
684 }
685 }
686
687 // ------------------------------------------------------------------
688 // ciTypeFlow::StateVector::do_jsr
689 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
690 push(ciReturnAddress::make(str->next_bci()));
691 }
692
693 // ------------------------------------------------------------------
694 // ciTypeFlow::StateVector::do_ldc
695 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
696 ciConstant con = str->get_constant();
697 BasicType basic_type = con.basic_type();
698 if (basic_type == T_ILLEGAL) {
699 // OutOfMemoryError in the CI while loading constant
700 push_null();
701 outer()->record_failure("ldc did not link");
702 return;
703 }
704 if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
705 ciObject* obj = con.as_object();
706 if (obj->is_null_object()) {
707 push_null();
708 } else if (obj->is_klass()) {
709 // The type of ldc <class> is java.lang.Class
710 push_object(outer()->env()->Class_klass());
711 } else {
712 push_object(obj->klass());
713 }
714 } else {
715 push_translate(ciType::make(basic_type));
716 }
717 }
718
719 // ------------------------------------------------------------------
720 // ciTypeFlow::StateVector::do_multianewarray
721 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
722 int dimensions = str->get_dimensions();
723 bool will_link;
724 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
725 if (!will_link) {
726 trap(str, array_klass, str->get_klass_index());
727 } else {
728 for (int i = 0; i < dimensions; i++) {
729 pop_int();
730 }
731 push_object(array_klass);
732 }
733 }
734
735 // ------------------------------------------------------------------
736 // ciTypeFlow::StateVector::do_new
737 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
738 bool will_link;
739 ciKlass* klass = str->get_klass(will_link);
740 if (!will_link || str->is_unresolved_klass()) {
741 trap(str, klass, str->get_klass_index());
742 } else {
743 push_object(klass);
744 }
745 }
746
747 // ------------------------------------------------------------------
748 // ciTypeFlow::StateVector::do_newarray
749 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
750 pop_int();
751 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
752 push_object(klass);
753 }
754
755 // ------------------------------------------------------------------
756 // ciTypeFlow::StateVector::do_putfield
757 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
758 do_putstatic(str);
759 if (_trap_bci != -1) return; // unloaded field holder, etc.
760 // could add assert here for type of object.
761 pop_object();
762 }
763
764 // ------------------------------------------------------------------
765 // ciTypeFlow::StateVector::do_putstatic
766 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
767 bool will_link;
768 ciField* field = str->get_field(will_link);
769 if (!will_link) {
770 trap(str, field->holder(), str->get_field_holder_index());
771 } else {
772 ciType* field_type = field->type();
773 ciType* type = pop_value();
774 // Do I want to check this type?
775 // assert(type->is_subtype_of(field_type), "bad type for field value");
776 if (field_type->is_two_word()) {
777 ciType* type2 = pop_value();
778 assert(type2->is_two_word(), "must be 2nd half");
779 assert(type == half_type(type2), "must be 2nd half");
780 }
781 }
782 }
783
784 // ------------------------------------------------------------------
785 // ciTypeFlow::StateVector::do_ret
786 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
787 Cell index = local(str->get_index());
788
789 ciType* address = type_at(index);
790 assert(address->is_return_address(), "bad return address");
791 set_type_at(index, bottom_type());
792 }
793
794 // ------------------------------------------------------------------
795 // ciTypeFlow::StateVector::trap
796 //
797 // Stop interpretation of this path with a trap.
798 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
799 _trap_bci = str->cur_bci();
800 _trap_index = index;
801
802 // Log information about this trap:
803 CompileLog* log = outer()->env()->log();
804 if (log != NULL) {
805 int mid = log->identify(outer()->method());
806 int kid = (klass == NULL)? -1: log->identify(klass);
807 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
808 char buf[100];
809 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
810 index));
811 if (kid >= 0)
812 log->print(" klass='%d'", kid);
813 log->end_elem();
814 }
815 }
816
817 // ------------------------------------------------------------------
818 // ciTypeFlow::StateVector::do_null_assert
819 // Corresponds to graphKit::do_null_assert.
820 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
821 if (unloaded_klass->is_loaded()) {
822 // We failed to link, but we can still compute with this class,
823 // since it is loaded somewhere. The compiler will uncommon_trap
824 // if the object is not null, but the typeflow pass can not assume
825 // that the object will be null, otherwise it may incorrectly tell
826 // the parser that an object is known to be null. 4761344, 4807707
827 push_object(unloaded_klass);
828 } else {
829 // The class is not loaded anywhere. It is safe to model the
830 // null in the typestates, because we can compile in a null check
831 // which will deoptimize us if someone manages to load the
832 // class later.
833 push_null();
834 }
835 }
836
837
838 // ------------------------------------------------------------------
839 // ciTypeFlow::StateVector::apply_one_bytecode
840 //
841 // Apply the effect of one bytecode to this StateVector
842 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
843 _trap_bci = -1;
844 _trap_index = 0;
845
846 if (CITraceTypeFlow) {
847 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
848 Bytecodes::name(str->cur_bc()));
849 }
850
851 switch(str->cur_bc()) {
852 case Bytecodes::_aaload: do_aaload(str); break;
853
854 case Bytecodes::_aastore:
855 {
856 pop_object();
857 pop_int();
858 pop_objArray();
859 break;
860 }
861 case Bytecodes::_aconst_null:
862 {
863 push_null();
864 break;
865 }
866 case Bytecodes::_aload: load_local_object(str->get_index()); break;
867 case Bytecodes::_aload_0: load_local_object(0); break;
868 case Bytecodes::_aload_1: load_local_object(1); break;
869 case Bytecodes::_aload_2: load_local_object(2); break;
870 case Bytecodes::_aload_3: load_local_object(3); break;
871
872 case Bytecodes::_anewarray:
873 {
874 pop_int();
875 bool will_link;
876 ciKlass* element_klass = str->get_klass(will_link);
877 if (!will_link) {
878 trap(str, element_klass, str->get_klass_index());
879 } else {
880 push_object(ciObjArrayKlass::make(element_klass));
881 }
882 break;
883 }
884 case Bytecodes::_areturn:
885 case Bytecodes::_ifnonnull:
886 case Bytecodes::_ifnull:
887 {
888 pop_object();
889 break;
890 }
891 case Bytecodes::_monitorenter:
892 {
893 pop_object();
894 set_monitor_count(monitor_count() + 1);
895 break;
896 }
897 case Bytecodes::_monitorexit:
898 {
899 pop_object();
900 assert(monitor_count() > 0, "must be a monitor to exit from");
901 set_monitor_count(monitor_count() - 1);
902 break;
903 }
904 case Bytecodes::_arraylength:
905 {
906 pop_array();
907 push_int();
908 break;
909 }
910 case Bytecodes::_astore: store_local_object(str->get_index()); break;
911 case Bytecodes::_astore_0: store_local_object(0); break;
912 case Bytecodes::_astore_1: store_local_object(1); break;
913 case Bytecodes::_astore_2: store_local_object(2); break;
914 case Bytecodes::_astore_3: store_local_object(3); break;
915
916 case Bytecodes::_athrow:
917 {
918 NEEDS_CLEANUP;
919 pop_object();
920 break;
921 }
922 case Bytecodes::_baload:
923 case Bytecodes::_caload:
924 case Bytecodes::_iaload:
925 case Bytecodes::_saload:
926 {
927 pop_int();
928 ciTypeArrayKlass* array_klass = pop_typeArray();
929 // Put assert here for right type?
930 push_int();
931 break;
932 }
933 case Bytecodes::_bastore:
934 case Bytecodes::_castore:
935 case Bytecodes::_iastore:
936 case Bytecodes::_sastore:
937 {
938 pop_int();
939 pop_int();
940 pop_typeArray();
941 // assert here?
942 break;
943 }
944 case Bytecodes::_bipush:
945 case Bytecodes::_iconst_m1:
946 case Bytecodes::_iconst_0:
947 case Bytecodes::_iconst_1:
948 case Bytecodes::_iconst_2:
949 case Bytecodes::_iconst_3:
950 case Bytecodes::_iconst_4:
951 case Bytecodes::_iconst_5:
952 case Bytecodes::_sipush:
953 {
954 push_int();
955 break;
956 }
957 case Bytecodes::_checkcast: do_checkcast(str); break;
958
959 case Bytecodes::_d2f:
960 {
961 pop_double();
962 push_float();
963 break;
964 }
965 case Bytecodes::_d2i:
966 {
967 pop_double();
968 push_int();
969 break;
970 }
971 case Bytecodes::_d2l:
972 {
973 pop_double();
974 push_long();
975 break;
976 }
977 case Bytecodes::_dadd:
978 case Bytecodes::_ddiv:
979 case Bytecodes::_dmul:
980 case Bytecodes::_drem:
981 case Bytecodes::_dsub:
982 {
983 pop_double();
984 pop_double();
985 push_double();
986 break;
987 }
988 case Bytecodes::_daload:
989 {
990 pop_int();
991 ciTypeArrayKlass* array_klass = pop_typeArray();
992 // Put assert here for right type?
993 push_double();
994 break;
995 }
996 case Bytecodes::_dastore:
997 {
998 pop_double();
999 pop_int();
1000 pop_typeArray();
1001 // assert here?
1002 break;
1003 }
1004 case Bytecodes::_dcmpg:
1005 case Bytecodes::_dcmpl:
1006 {
1007 pop_double();
1008 pop_double();
1009 push_int();
1010 break;
1011 }
1012 case Bytecodes::_dconst_0:
1013 case Bytecodes::_dconst_1:
1014 {
1015 push_double();
1016 break;
1017 }
1018 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1019 case Bytecodes::_dload_0: load_local_double(0); break;
1020 case Bytecodes::_dload_1: load_local_double(1); break;
1021 case Bytecodes::_dload_2: load_local_double(2); break;
1022 case Bytecodes::_dload_3: load_local_double(3); break;
1023
1024 case Bytecodes::_dneg:
1025 {
1026 pop_double();
1027 push_double();
1028 break;
1029 }
1030 case Bytecodes::_dreturn:
1031 {
1032 pop_double();
1033 break;
1034 }
1035 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1036 case Bytecodes::_dstore_0: store_local_double(0); break;
1037 case Bytecodes::_dstore_1: store_local_double(1); break;
1038 case Bytecodes::_dstore_2: store_local_double(2); break;
1039 case Bytecodes::_dstore_3: store_local_double(3); break;
1040
1041 case Bytecodes::_dup:
1042 {
1043 push(type_at_tos());
1044 break;
1045 }
1046 case Bytecodes::_dup_x1:
1047 {
1048 ciType* value1 = pop_value();
1049 ciType* value2 = pop_value();
1050 push(value1);
1051 push(value2);
1052 push(value1);
1053 break;
1054 }
1055 case Bytecodes::_dup_x2:
1056 {
1057 ciType* value1 = pop_value();
1058 ciType* value2 = pop_value();
1059 ciType* value3 = pop_value();
1060 push(value1);
1061 push(value3);
1062 push(value2);
1063 push(value1);
1064 break;
1065 }
1066 case Bytecodes::_dup2:
1067 {
1068 ciType* value1 = pop_value();
1069 ciType* value2 = pop_value();
1070 push(value2);
1071 push(value1);
1072 push(value2);
1073 push(value1);
1074 break;
1075 }
1076 case Bytecodes::_dup2_x1:
1077 {
1078 ciType* value1 = pop_value();
1079 ciType* value2 = pop_value();
1080 ciType* value3 = pop_value();
1081 push(value2);
1082 push(value1);
1083 push(value3);
1084 push(value2);
1085 push(value1);
1086 break;
1087 }
1088 case Bytecodes::_dup2_x2:
1089 {
1090 ciType* value1 = pop_value();
1091 ciType* value2 = pop_value();
1092 ciType* value3 = pop_value();
1093 ciType* value4 = pop_value();
1094 push(value2);
1095 push(value1);
1096 push(value4);
1097 push(value3);
1098 push(value2);
1099 push(value1);
1100 break;
1101 }
1102 case Bytecodes::_f2d:
1103 {
1104 pop_float();
1105 push_double();
1106 break;
1107 }
1108 case Bytecodes::_f2i:
1109 {
1110 pop_float();
1111 push_int();
1112 break;
1113 }
1114 case Bytecodes::_f2l:
1115 {
1116 pop_float();
1117 push_long();
1118 break;
1119 }
1120 case Bytecodes::_fadd:
1121 case Bytecodes::_fdiv:
1122 case Bytecodes::_fmul:
1123 case Bytecodes::_frem:
1124 case Bytecodes::_fsub:
1125 {
1126 pop_float();
1127 pop_float();
1128 push_float();
1129 break;
1130 }
1131 case Bytecodes::_faload:
1132 {
1133 pop_int();
1134 ciTypeArrayKlass* array_klass = pop_typeArray();
1135 // Put assert here.
1136 push_float();
1137 break;
1138 }
1139 case Bytecodes::_fastore:
1140 {
1141 pop_float();
1142 pop_int();
1143 ciTypeArrayKlass* array_klass = pop_typeArray();
1144 // Put assert here.
1145 break;
1146 }
1147 case Bytecodes::_fcmpg:
1148 case Bytecodes::_fcmpl:
1149 {
1150 pop_float();
1151 pop_float();
1152 push_int();
1153 break;
1154 }
1155 case Bytecodes::_fconst_0:
1156 case Bytecodes::_fconst_1:
1157 case Bytecodes::_fconst_2:
1158 {
1159 push_float();
1160 break;
1161 }
1162 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1163 case Bytecodes::_fload_0: load_local_float(0); break;
1164 case Bytecodes::_fload_1: load_local_float(1); break;
1165 case Bytecodes::_fload_2: load_local_float(2); break;
1166 case Bytecodes::_fload_3: load_local_float(3); break;
1167
1168 case Bytecodes::_fneg:
1169 {
1170 pop_float();
1171 push_float();
1172 break;
1173 }
1174 case Bytecodes::_freturn:
1175 {
1176 pop_float();
1177 break;
1178 }
1179 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1180 case Bytecodes::_fstore_0: store_local_float(0); break;
1181 case Bytecodes::_fstore_1: store_local_float(1); break;
1182 case Bytecodes::_fstore_2: store_local_float(2); break;
1183 case Bytecodes::_fstore_3: store_local_float(3); break;
1184
1185 case Bytecodes::_getfield: do_getfield(str); break;
1186 case Bytecodes::_getstatic: do_getstatic(str); break;
1187
1188 case Bytecodes::_goto:
1189 case Bytecodes::_goto_w:
1190 case Bytecodes::_nop:
1191 case Bytecodes::_return:
1192 {
1193 // do nothing.
1194 break;
1195 }
1196 case Bytecodes::_i2b:
1197 case Bytecodes::_i2c:
1198 case Bytecodes::_i2s:
1199 case Bytecodes::_ineg:
1200 {
1201 pop_int();
1202 push_int();
1203 break;
1204 }
1205 case Bytecodes::_i2d:
1206 {
1207 pop_int();
1208 push_double();
1209 break;
1210 }
1211 case Bytecodes::_i2f:
1212 {
1213 pop_int();
1214 push_float();
1215 break;
1216 }
1217 case Bytecodes::_i2l:
1218 {
1219 pop_int();
1220 push_long();
1221 break;
1222 }
1223 case Bytecodes::_iadd:
1224 case Bytecodes::_iand:
1225 case Bytecodes::_idiv:
1226 case Bytecodes::_imul:
1227 case Bytecodes::_ior:
1228 case Bytecodes::_irem:
1229 case Bytecodes::_ishl:
1230 case Bytecodes::_ishr:
1231 case Bytecodes::_isub:
1232 case Bytecodes::_iushr:
1233 case Bytecodes::_ixor:
1234 {
1235 pop_int();
1236 pop_int();
1237 push_int();
1238 break;
1239 }
1240 case Bytecodes::_if_acmpeq:
1241 case Bytecodes::_if_acmpne:
1242 {
1243 pop_object();
1244 pop_object();
1245 break;
1246 }
1247 case Bytecodes::_if_icmpeq:
1248 case Bytecodes::_if_icmpge:
1249 case Bytecodes::_if_icmpgt:
1250 case Bytecodes::_if_icmple:
1251 case Bytecodes::_if_icmplt:
1252 case Bytecodes::_if_icmpne:
1253 {
1254 pop_int();
1255 pop_int();
1256 break;
1257 }
1258 case Bytecodes::_ifeq:
1259 case Bytecodes::_ifle:
1260 case Bytecodes::_iflt:
1261 case Bytecodes::_ifge:
1262 case Bytecodes::_ifgt:
1263 case Bytecodes::_ifne:
1264 case Bytecodes::_ireturn:
1265 case Bytecodes::_lookupswitch:
1266 case Bytecodes::_tableswitch:
1267 {
1268 pop_int();
1269 break;
1270 }
1271 case Bytecodes::_iinc:
1272 {
1273 int lnum = str->get_index();
1274 check_int(local(lnum));
1275 store_to_local(lnum);
1276 break;
1277 }
1278 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1279 case Bytecodes::_iload_0: load_local_int(0); break;
1280 case Bytecodes::_iload_1: load_local_int(1); break;
1281 case Bytecodes::_iload_2: load_local_int(2); break;
1282 case Bytecodes::_iload_3: load_local_int(3); break;
1283
1284 case Bytecodes::_instanceof:
1285 {
1286 // Check for uncommon trap:
1287 do_checkcast(str);
1288 pop_object();
1289 push_int();
1290 break;
1291 }
1292 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1293 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1294 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1295
1296 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1297
1298 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1299 case Bytecodes::_istore_0: store_local_int(0); break;
1300 case Bytecodes::_istore_1: store_local_int(1); break;
1301 case Bytecodes::_istore_2: store_local_int(2); break;
1302 case Bytecodes::_istore_3: store_local_int(3); break;
1303
1304 case Bytecodes::_jsr:
1305 case Bytecodes::_jsr_w: do_jsr(str); break;
1306
1307 case Bytecodes::_l2d:
1308 {
1309 pop_long();
1310 push_double();
1311 break;
1312 }
1313 case Bytecodes::_l2f:
1314 {
1315 pop_long();
1316 push_float();
1317 break;
1318 }
1319 case Bytecodes::_l2i:
1320 {
1321 pop_long();
1322 push_int();
1323 break;
1324 }
1325 case Bytecodes::_ladd:
1326 case Bytecodes::_land:
1327 case Bytecodes::_ldiv:
1328 case Bytecodes::_lmul:
1329 case Bytecodes::_lor:
1330 case Bytecodes::_lrem:
1331 case Bytecodes::_lsub:
1332 case Bytecodes::_lxor:
1333 {
1334 pop_long();
1335 pop_long();
1336 push_long();
1337 break;
1338 }
1339 case Bytecodes::_laload:
1340 {
1341 pop_int();
1342 ciTypeArrayKlass* array_klass = pop_typeArray();
1343 // Put assert here for right type?
1344 push_long();
1345 break;
1346 }
1347 case Bytecodes::_lastore:
1348 {
1349 pop_long();
1350 pop_int();
1351 pop_typeArray();
1352 // assert here?
1353 break;
1354 }
1355 case Bytecodes::_lcmp:
1356 {
1357 pop_long();
1358 pop_long();
1359 push_int();
1360 break;
1361 }
1362 case Bytecodes::_lconst_0:
1363 case Bytecodes::_lconst_1:
1364 {
1365 push_long();
1366 break;
1367 }
1368 case Bytecodes::_ldc:
1369 case Bytecodes::_ldc_w:
1370 case Bytecodes::_ldc2_w:
1371 {
1372 do_ldc(str);
1373 break;
1374 }
1375
1376 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1377 case Bytecodes::_lload_0: load_local_long(0); break;
1378 case Bytecodes::_lload_1: load_local_long(1); break;
1379 case Bytecodes::_lload_2: load_local_long(2); break;
1380 case Bytecodes::_lload_3: load_local_long(3); break;
1381
1382 case Bytecodes::_lneg:
1383 {
1384 pop_long();
1385 push_long();
1386 break;
1387 }
1388 case Bytecodes::_lreturn:
1389 {
1390 pop_long();
1391 break;
1392 }
1393 case Bytecodes::_lshl:
1394 case Bytecodes::_lshr:
1395 case Bytecodes::_lushr:
1396 {
1397 pop_int();
1398 pop_long();
1399 push_long();
1400 break;
1401 }
1402 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1403 case Bytecodes::_lstore_0: store_local_long(0); break;
1404 case Bytecodes::_lstore_1: store_local_long(1); break;
1405 case Bytecodes::_lstore_2: store_local_long(2); break;
1406 case Bytecodes::_lstore_3: store_local_long(3); break;
1407
1408 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1409
1410 case Bytecodes::_new: do_new(str); break;
1411
1412 case Bytecodes::_newarray: do_newarray(str); break;
1413
1414 case Bytecodes::_pop:
1415 {
1416 pop();
1417 break;
1418 }
1419 case Bytecodes::_pop2:
1420 {
1421 pop();
1422 pop();
1423 break;
1424 }
1425
1426 case Bytecodes::_putfield: do_putfield(str); break;
1427 case Bytecodes::_putstatic: do_putstatic(str); break;
1428
1429 case Bytecodes::_ret: do_ret(str); break;
1430
1431 case Bytecodes::_swap:
1432 {
1433 ciType* value1 = pop_value();
1434 ciType* value2 = pop_value();
1435 push(value1);
1436 push(value2);
1437 break;
1438 }
1439 case Bytecodes::_wide:
1440 default:
1441 {
1442 // The iterator should skip this.
1443 ShouldNotReachHere();
1444 break;
1445 }
1446 }
1447
1448 if (CITraceTypeFlow) {
1449 print_on(tty);
1450 }
1451
1452 return (_trap_bci != -1);
1453 }
1454
1455 #ifndef PRODUCT
1456 // ------------------------------------------------------------------
1457 // ciTypeFlow::StateVector::print_cell_on
1458 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1459 ciType* type = type_at(c);
1460 if (type == top_type()) {
1461 st->print("top");
1462 } else if (type == bottom_type()) {
1463 st->print("bottom");
1464 } else if (type == null_type()) {
1465 st->print("null");
1466 } else if (type == long2_type()) {
1467 st->print("long2");
1468 } else if (type == double2_type()) {
1469 st->print("double2");
1470 } else if (is_int(type)) {
1471 st->print("int");
1472 } else if (is_long(type)) {
1473 st->print("long");
1474 } else if (is_float(type)) {
1475 st->print("float");
1476 } else if (is_double(type)) {
1477 st->print("double");
1478 } else if (type->is_return_address()) {
1479 st->print("address(%d)", type->as_return_address()->bci());
1480 } else {
1481 if (type->is_klass()) {
1482 type->as_klass()->name()->print_symbol_on(st);
1483 } else {
1484 st->print("UNEXPECTED TYPE");
1485 type->print();
1486 }
1487 }
1488 }
1489
1490 // ------------------------------------------------------------------
1491 // ciTypeFlow::StateVector::print_on
1492 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1493 int num_locals = _outer->max_locals();
1494 int num_stack = stack_size();
1495 int num_monitors = monitor_count();
1496 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1497 if (num_stack >= 0) {
1498 int i;
1499 for (i = 0; i < num_locals; i++) {
1500 st->print(" local %2d : ", i);
1501 print_cell_on(st, local(i));
1502 st->cr();
1503 }
1504 for (i = 0; i < num_stack; i++) {
1505 st->print(" stack %2d : ", i);
1506 print_cell_on(st, stack(i));
1507 st->cr();
1508 }
1509 }
1510 }
1511 #endif
1512
1513
1514 // ------------------------------------------------------------------
1515 // ciTypeFlow::SuccIter::next
1516 //
1517 void ciTypeFlow::SuccIter::next() {
1518 int succ_ct = _pred->successors()->length();
1519 int next = _index + 1;
1520 if (next < succ_ct) {
1521 _index = next;
1522 _succ = _pred->successors()->at(next);
1523 return;
1524 }
1525 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1526 // Do not compile any code for unloaded exception types.
1527 // Following compiler passes are responsible for doing this also.
1528 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1529 if (exception_klass->is_loaded()) {
1530 _index = next;
1531 _succ = _pred->exceptions()->at(i);
1532 return;
1533 }
1534 next++;
1535 }
1536 _index = -1;
1537 _succ = NULL;
1538 }
1539
1540 // ------------------------------------------------------------------
1541 // ciTypeFlow::SuccIter::set_succ
1542 //
1543 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1544 int succ_ct = _pred->successors()->length();
1545 if (_index < succ_ct) {
1546 _pred->successors()->at_put(_index, succ);
1547 } else {
1548 int idx = _index - succ_ct;
1549 _pred->exceptions()->at_put(idx, succ);
1550 }
1551 }
1552
1553 // ciTypeFlow::Block
1554 //
1555 // A basic block.
1556
1557 // ------------------------------------------------------------------
1558 // ciTypeFlow::Block::Block
1559 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1560 ciBlock *ciblk,
1561 ciTypeFlow::JsrSet* jsrs) {
1562 _ciblock = ciblk;
1563 _exceptions = NULL;
1564 _exc_klasses = NULL;
1565 _successors = NULL;
1566 _state = new (outer->arena()) StateVector(outer);
1567 JsrSet* new_jsrs =
1568 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1569 jsrs->copy_into(new_jsrs);
1570 _jsrs = new_jsrs;
1571 _next = NULL;
1572 _on_work_list = false;
1573 _backedge_copy = false;
1574 _exception_entry = false;
1575 _trap_bci = -1;
1576 _trap_index = 0;
1577 df_init();
1578
1579 if (CITraceTypeFlow) {
1580 tty->print_cr(">> Created new block");
1581 print_on(tty);
1582 }
1583
1584 assert(this->outer() == outer, "outer link set up");
1585 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1586 }
1587
1588 // ------------------------------------------------------------------
1589 // ciTypeFlow::Block::df_init
1590 void ciTypeFlow::Block::df_init() {
1591 _pre_order = -1; assert(!has_pre_order(), "");
1592 _post_order = -1; assert(!has_post_order(), "");
1593 _loop = NULL;
1594 _irreducible_entry = false;
1595 _rpo_next = NULL;
1596 }
1597
1598 // ------------------------------------------------------------------
1599 // ciTypeFlow::Block::successors
1600 //
1601 // Get the successors for this Block.
1602 GrowableArray<ciTypeFlow::Block*>*
1603 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1604 ciTypeFlow::StateVector* state,
1605 ciTypeFlow::JsrSet* jsrs) {
1606 if (_successors == NULL) {
1607 if (CITraceTypeFlow) {
1608 tty->print(">> Computing successors for block ");
1609 print_value_on(tty);
1610 tty->cr();
1611 }
1612
1613 ciTypeFlow* analyzer = outer();
1614 Arena* arena = analyzer->arena();
1615 Block* block = NULL;
1616 bool has_successor = !has_trap() &&
1617 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1618 if (!has_successor) {
1619 _successors =
1620 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1621 // No successors
1622 } else if (control() == ciBlock::fall_through_bci) {
1623 assert(str->cur_bci() == limit(), "bad block end");
1624 // This block simply falls through to the next.
1625 _successors =
1626 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1627
1628 Block* block = analyzer->block_at(limit(), _jsrs);
1629 assert(_successors->length() == FALL_THROUGH, "");
1630 _successors->append(block);
1631 } else {
1632 int current_bci = str->cur_bci();
1633 int next_bci = str->next_bci();
1634 int branch_bci = -1;
1635 Block* target = NULL;
1636 assert(str->next_bci() == limit(), "bad block end");
1637 // This block is not a simple fall-though. Interpret
1638 // the current bytecode to find our successors.
1639 switch (str->cur_bc()) {
1640 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1641 case Bytecodes::_iflt: case Bytecodes::_ifge:
1642 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1643 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1644 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1645 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1646 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1647 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1648 // Our successors are the branch target and the next bci.
1649 branch_bci = str->get_dest();
1650 _successors =
1651 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1652 assert(_successors->length() == IF_NOT_TAKEN, "");
1653 _successors->append(analyzer->block_at(next_bci, jsrs));
1654 assert(_successors->length() == IF_TAKEN, "");
1655 _successors->append(analyzer->block_at(branch_bci, jsrs));
1656 break;
1657
1658 case Bytecodes::_goto:
1659 branch_bci = str->get_dest();
1660 _successors =
1661 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1662 assert(_successors->length() == GOTO_TARGET, "");
1663 _successors->append(analyzer->block_at(branch_bci, jsrs));
1664 break;
1665
1666 case Bytecodes::_jsr:
1667 branch_bci = str->get_dest();
1668 _successors =
1669 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1670 assert(_successors->length() == GOTO_TARGET, "");
1671 _successors->append(analyzer->block_at(branch_bci, jsrs));
1672 break;
1673
1674 case Bytecodes::_goto_w:
1675 case Bytecodes::_jsr_w:
1676 _successors =
1677 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1678 assert(_successors->length() == GOTO_TARGET, "");
1679 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1680 break;
1681
1682 case Bytecodes::_tableswitch: {
1683 Bytecode_tableswitch *tableswitch =
1684 Bytecode_tableswitch_at(str->cur_bcp());
1685
1686 int len = tableswitch->length();
1687 _successors =
1688 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1689 int bci = current_bci + tableswitch->default_offset();
1690 Block* block = analyzer->block_at(bci, jsrs);
1691 assert(_successors->length() == SWITCH_DEFAULT, "");
1692 _successors->append(block);
1693 while (--len >= 0) {
1694 int bci = current_bci + tableswitch->dest_offset_at(len);
1695 block = analyzer->block_at(bci, jsrs);
1696 assert(_successors->length() >= SWITCH_CASES, "");
1697 _successors->append_if_missing(block);
1698 }
1699 break;
1700 }
1701
1702 case Bytecodes::_lookupswitch: {
1703 Bytecode_lookupswitch *lookupswitch =
1704 Bytecode_lookupswitch_at(str->cur_bcp());
1705
1706 int npairs = lookupswitch->number_of_pairs();
1707 _successors =
1708 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1709 int bci = current_bci + lookupswitch->default_offset();
1710 Block* block = analyzer->block_at(bci, jsrs);
1711 assert(_successors->length() == SWITCH_DEFAULT, "");
1712 _successors->append(block);
1713 while(--npairs >= 0) {
1714 LookupswitchPair *pair = lookupswitch->pair_at(npairs);
1715 int bci = current_bci + pair->offset();
1716 Block* block = analyzer->block_at(bci, jsrs);
1717 assert(_successors->length() >= SWITCH_CASES, "");
1718 _successors->append_if_missing(block);
1719 }
1720 break;
1721 }
1722
1723 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1724 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1725 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1726 case Bytecodes::_return:
1727 _successors =
1728 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1729 // No successors
1730 break;
1731
1732 case Bytecodes::_ret: {
1733 _successors =
1734 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1735
1736 Cell local = state->local(str->get_index());
1737 ciType* return_address = state->type_at(local);
1738 assert(return_address->is_return_address(), "verify: wrong type");
1739 int bci = return_address->as_return_address()->bci();
1740 assert(_successors->length() == GOTO_TARGET, "");
1741 _successors->append(analyzer->block_at(bci, jsrs));
1742 break;
1743 }
1744
1745 case Bytecodes::_wide:
1746 default:
1747 ShouldNotReachHere();
1748 break;
1749 }
1750 }
1751 }
1752 return _successors;
1753 }
1754
1755 // ------------------------------------------------------------------
1756 // ciTypeFlow::Block:compute_exceptions
1757 //
1758 // Compute the exceptional successors and types for this Block.
1759 void ciTypeFlow::Block::compute_exceptions() {
1760 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1761
1762 if (CITraceTypeFlow) {
1763 tty->print(">> Computing exceptions for block ");
1764 print_value_on(tty);
1765 tty->cr();
1766 }
1767
1768 ciTypeFlow* analyzer = outer();
1769 Arena* arena = analyzer->arena();
1770
1771 // Any bci in the block will do.
1772 ciExceptionHandlerStream str(analyzer->method(), start());
1773
1774 // Allocate our growable arrays.
1775 int exc_count = str.count();
1776 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1777 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1778 0, NULL);
1779
1780 for ( ; !str.is_done(); str.next()) {
1781 ciExceptionHandler* handler = str.handler();
1782 int bci = handler->handler_bci();
1783 ciInstanceKlass* klass = NULL;
1784 if (bci == -1) {
1785 // There is no catch all. It is possible to exit the method.
1786 break;
1787 }
1788 if (handler->is_catch_all()) {
1789 klass = analyzer->env()->Throwable_klass();
1790 } else {
1791 klass = handler->catch_klass();
1792 }
1793 _exceptions->append(analyzer->block_at(bci, _jsrs));
1794 _exc_klasses->append(klass);
1795 }
1796 }
1797
1798 // ------------------------------------------------------------------
1799 // ciTypeFlow::Block::set_backedge_copy
1800 // Use this only to make a pre-existing public block into a backedge copy.
1801 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1802 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1803 _backedge_copy = z;
1804 }
1805
1806 // ------------------------------------------------------------------
1807 // ciTypeFlow::Block::is_clonable_exit
1808 //
1809 // At most 2 normal successors, one of which continues looping,
1810 // and all exceptional successors must exit.
1811 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1812 int normal_cnt = 0;
1813 int in_loop_cnt = 0;
1814 for (SuccIter iter(this); !iter.done(); iter.next()) {
1815 Block* succ = iter.succ();
1816 if (iter.is_normal_ctrl()) {
1817 if (++normal_cnt > 2) return false;
1818 if (lp->contains(succ->loop())) {
1819 if (++in_loop_cnt > 1) return false;
1820 }
1821 } else {
1822 if (lp->contains(succ->loop())) return false;
1823 }
1824 }
1825 return in_loop_cnt == 1;
1826 }
1827
1828 // ------------------------------------------------------------------
1829 // ciTypeFlow::Block::looping_succ
1830 //
1831 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1832 assert(successors()->length() <= 2, "at most 2 normal successors");
1833 for (SuccIter iter(this); !iter.done(); iter.next()) {
1834 Block* succ = iter.succ();
1835 if (lp->contains(succ->loop())) {
1836 return succ;
1837 }
1838 }
1839 return NULL;
1840 }
1841
1842 #ifndef PRODUCT
1843 // ------------------------------------------------------------------
1844 // ciTypeFlow::Block::print_value_on
1845 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1846 if (has_pre_order()) st->print("#%-2d ", pre_order());
1847 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1848 st->print("[%d - %d)", start(), limit());
1849 if (is_loop_head()) st->print(" lphd");
1850 if (is_irreducible_entry()) st->print(" irred");
1851 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1852 if (is_backedge_copy()) st->print("/backedge_copy");
1853 }
1854
1855 // ------------------------------------------------------------------
1856 // ciTypeFlow::Block::print_on
1857 void ciTypeFlow::Block::print_on(outputStream* st) const {
1858 if ((Verbose || WizardMode)) {
1859 outer()->method()->print_codes_on(start(), limit(), st);
1860 }
1861 st->print_cr(" ==================================================== ");
1862 st->print (" ");
1863 print_value_on(st);
1864 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1865 if (loop() && loop()->parent() != NULL) {
1866 st->print(" loops:");
1867 Loop* lp = loop();
1868 do {
1869 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1870 if (lp->is_irreducible()) st->print("(ir)");
1871 lp = lp->parent();
1872 } while (lp->parent() != NULL);
1873 }
1874 st->cr();
1875 _state->print_on(st);
1876 if (_successors == NULL) {
1877 st->print_cr(" No successor information");
1878 } else {
1879 int num_successors = _successors->length();
1880 st->print_cr(" Successors : %d", num_successors);
1881 for (int i = 0; i < num_successors; i++) {
1882 Block* successor = _successors->at(i);
1883 st->print(" ");
1884 successor->print_value_on(st);
1885 st->cr();
1886 }
1887 }
1888 if (_exceptions == NULL) {
1889 st->print_cr(" No exception information");
1890 } else {
1891 int num_exceptions = _exceptions->length();
1892 st->print_cr(" Exceptions : %d", num_exceptions);
1893 for (int i = 0; i < num_exceptions; i++) {
1894 Block* exc_succ = _exceptions->at(i);
1895 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1896 st->print(" ");
1897 exc_succ->print_value_on(st);
1898 st->print(" -- ");
1899 exc_klass->name()->print_symbol_on(st);
1900 st->cr();
1901 }
1902 }
1903 if (has_trap()) {
1904 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1905 }
1906 st->print_cr(" ==================================================== ");
1907 }
1908 #endif
1909
1910 #ifndef PRODUCT
1911 // ------------------------------------------------------------------
1912 // ciTypeFlow::LocalSet::print_on
1913 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
1914 st->print("{");
1915 for (int i = 0; i < max; i++) {
1916 if (test(i)) st->print(" %d", i);
1917 }
1918 if (limit > max) {
1919 st->print(" %d..%d ", max, limit);
1920 }
1921 st->print(" }");
1922 }
1923 #endif
1924
1925 // ciTypeFlow
1926 //
1927 // This is a pass over the bytecodes which computes the following:
1928 // basic block structure
1929 // interpreter type-states (a la the verifier)
1930
1931 // ------------------------------------------------------------------
1932 // ciTypeFlow::ciTypeFlow
1933 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
1934 _env = env;
1935 _method = method;
1936 _methodBlocks = method->get_method_blocks();
1937 _max_locals = method->max_locals();
1938 _max_stack = method->max_stack();
1939 _code_size = method->code_size();
1940 _has_irreducible_entry = false;
1941 _osr_bci = osr_bci;
1942 _failure_reason = NULL;
1943 assert(start_bci() >= 0 && start_bci() < code_size() , "correct osr_bci argument");
1944 _work_list = NULL;
1945
1946 _ciblock_count = _methodBlocks->num_blocks();
1947 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
1948 for (int i = 0; i < _ciblock_count; i++) {
1949 _idx_to_blocklist[i] = NULL;
1950 }
1951 _block_map = NULL; // until all blocks are seen
1952 _jsr_count = 0;
1953 _jsr_records = NULL;
1954 }
1955
1956 // ------------------------------------------------------------------
1957 // ciTypeFlow::work_list_next
1958 //
1959 // Get the next basic block from our work list.
1960 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
1961 assert(!work_list_empty(), "work list must not be empty");
1962 Block* next_block = _work_list;
1963 _work_list = next_block->next();
1964 next_block->set_next(NULL);
1965 next_block->set_on_work_list(false);
1966 return next_block;
1967 }
1968
1969 // ------------------------------------------------------------------
1970 // ciTypeFlow::add_to_work_list
1971 //
1972 // Add a basic block to our work list.
1973 // List is sorted by decreasing postorder sort (same as increasing RPO)
1974 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
1975 assert(!block->is_on_work_list(), "must not already be on work list");
1976
1977 if (CITraceTypeFlow) {
1978 tty->print(">> Adding block ");
1979 block->print_value_on(tty);
1980 tty->print_cr(" to the work list : ");
1981 }
1982
1983 block->set_on_work_list(true);
1984
1985 // decreasing post order sort
1986
1987 Block* prev = NULL;
1988 Block* current = _work_list;
1989 int po = block->post_order();
1990 while (current != NULL) {
1991 if (!current->has_post_order() || po > current->post_order())
1992 break;
1993 prev = current;
1994 current = current->next();
1995 }
1996 if (prev == NULL) {
1997 block->set_next(_work_list);
1998 _work_list = block;
1999 } else {
2000 block->set_next(current);
2001 prev->set_next(block);
2002 }
2003
2004 if (CITraceTypeFlow) {
2005 tty->cr();
2006 }
2007 }
2008
2009 // ------------------------------------------------------------------
2010 // ciTypeFlow::block_at
2011 //
2012 // Return the block beginning at bci which has a JsrSet compatible
2013 // with jsrs.
2014 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2015 // First find the right ciBlock.
2016 if (CITraceTypeFlow) {
2017 tty->print(">> Requesting block for %d/", bci);
2018 jsrs->print_on(tty);
2019 tty->cr();
2020 }
2021
2022 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2023 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2024 Block* block = get_block_for(ciblk->index(), jsrs, option);
2025
2026 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2027
2028 if (CITraceTypeFlow) {
2029 if (block != NULL) {
2030 tty->print(">> Found block ");
2031 block->print_value_on(tty);
2032 tty->cr();
2033 } else {
2034 tty->print_cr(">> No such block.");
2035 }
2036 }
2037
2038 return block;
2039 }
2040
2041 // ------------------------------------------------------------------
2042 // ciTypeFlow::make_jsr_record
2043 //
2044 // Make a JsrRecord for a given (entry, return) pair, if such a record
2045 // does not already exist.
2046 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2047 int return_address) {
2048 if (_jsr_records == NULL) {
2049 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2050 _jsr_count,
2051 0,
2052 NULL);
2053 }
2054 JsrRecord* record = NULL;
2055 int len = _jsr_records->length();
2056 for (int i = 0; i < len; i++) {
2057 JsrRecord* record = _jsr_records->at(i);
2058 if (record->entry_address() == entry_address &&
2059 record->return_address() == return_address) {
2060 return record;
2061 }
2062 }
2063
2064 record = new (arena()) JsrRecord(entry_address, return_address);
2065 _jsr_records->append(record);
2066 return record;
2067 }
2068
2069 // ------------------------------------------------------------------
2070 // ciTypeFlow::flow_exceptions
2071 //
2072 // Merge the current state into all exceptional successors at the
2073 // current point in the code.
2074 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2075 GrowableArray<ciInstanceKlass*>* exc_klasses,
2076 ciTypeFlow::StateVector* state) {
2077 int len = exceptions->length();
2078 assert(exc_klasses->length() == len, "must have same length");
2079 for (int i = 0; i < len; i++) {
2080 Block* block = exceptions->at(i);
2081 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2082
2083 if (!exception_klass->is_loaded()) {
2084 // Do not compile any code for unloaded exception types.
2085 // Following compiler passes are responsible for doing this also.
2086 continue;
2087 }
2088
2089 if (block->meet_exception(exception_klass, state)) {
2090 // Block was modified and has PO. Add it to the work list.
2091 if (block->has_post_order() &&
2092 !block->is_on_work_list()) {
2093 add_to_work_list(block);
2094 }
2095 }
2096 }
2097 }
2098
2099 // ------------------------------------------------------------------
2100 // ciTypeFlow::flow_successors
2101 //
2102 // Merge the current state into all successors at the current point
2103 // in the code.
2104 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2105 ciTypeFlow::StateVector* state) {
2106 int len = successors->length();
2107 for (int i = 0; i < len; i++) {
2108 Block* block = successors->at(i);
2109 if (block->meet(state)) {
2110 // Block was modified and has PO. Add it to the work list.
2111 if (block->has_post_order() &&
2112 !block->is_on_work_list()) {
2113 add_to_work_list(block);
2114 }
2115 }
2116 }
2117 }
2118
2119 // ------------------------------------------------------------------
2120 // ciTypeFlow::can_trap
2121 //
2122 // Tells if a given instruction is able to generate an exception edge.
2123 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2124 // Cf. GenerateOopMap::do_exception_edge.
2125 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2126
2127 switch (str.cur_bc()) {
2128 case Bytecodes::_ldc:
2129 case Bytecodes::_ldc_w:
2130 case Bytecodes::_ldc2_w:
2131 case Bytecodes::_aload_0:
2132 // These bytecodes can trap for rewriting. We need to assume that
2133 // they do not throw exceptions to make the monitor analysis work.
2134 return false;
2135
2136 case Bytecodes::_ireturn:
2137 case Bytecodes::_lreturn:
2138 case Bytecodes::_freturn:
2139 case Bytecodes::_dreturn:
2140 case Bytecodes::_areturn:
2141 case Bytecodes::_return:
2142 // We can assume the monitor stack is empty in this analysis.
2143 return false;
2144
2145 case Bytecodes::_monitorexit:
2146 // We can assume monitors are matched in this analysis.
2147 return false;
2148 }
2149
2150 return true;
2151 }
2152
2153 // ------------------------------------------------------------------
2154 // ciTypeFlow::clone_loop_heads
2155 //
2156 // Clone the loop heads
2157 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2158 bool rslt = false;
2159 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2160 lp = iter.current();
2161 Block* head = lp->head();
2162 if (lp == loop_tree_root() ||
2163 lp->is_irreducible() ||
2164 !head->is_clonable_exit(lp))
2165 continue;
2166
2167 // check not already cloned
2168 if (head->backedge_copy_count() != 0)
2169 continue;
2170
2171 // check _no_ shared head below us
2172 Loop* ch;
2173 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2174 if (ch != NULL)
2175 continue;
2176
2177 // Clone head
2178 Block* new_head = head->looping_succ(lp);
2179 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2180 // Update lp's info
2181 clone->set_loop(lp);
2182 lp->set_head(new_head);
2183 lp->set_tail(clone);
2184 // And move original head into outer loop
2185 head->set_loop(lp->parent());
2186
2187 rslt = true;
2188 }
2189 return rslt;
2190 }
2191
2192 // ------------------------------------------------------------------
2193 // ciTypeFlow::clone_loop_head
2194 //
2195 // Clone lp's head and replace tail's successors with clone.
2196 //
2197 // |
2198 // v
2199 // head <-> body
2200 // |
2201 // v
2202 // exit
2203 //
2204 // new_head
2205 //
2206 // |
2207 // v
2208 // head ----------\
2209 // | |
2210 // | v
2211 // | clone <-> body
2212 // | |
2213 // | /--/
2214 // | |
2215 // v v
2216 // exit
2217 //
2218 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2219 Block* head = lp->head();
2220 Block* tail = lp->tail();
2221 if (CITraceTypeFlow) {
2222 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2223 tty->print(" for predecessor "); tail->print_value_on(tty);
2224 tty->cr();
2225 }
2226 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2227 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2228
2229 assert(!clone->has_pre_order(), "just created");
2230 clone->set_next_pre_order();
2231
2232 // Insert clone after (orig) tail in reverse post order
2233 clone->set_rpo_next(tail->rpo_next());
2234 tail->set_rpo_next(clone);
2235
2236 // tail->head becomes tail->clone
2237 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2238 if (iter.succ() == head) {
2239 iter.set_succ(clone);
2240 }
2241 }
2242 flow_block(tail, temp_vector, temp_set);
2243 if (head == tail) {
2244 // For self-loops, clone->head becomes clone->clone
2245 flow_block(clone, temp_vector, temp_set);
2246 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2247 if (iter.succ() == head) {
2248 iter.set_succ(clone);
2249 break;
2250 }
2251 }
2252 }
2253 flow_block(clone, temp_vector, temp_set);
2254
2255 return clone;
2256 }
2257
2258 // ------------------------------------------------------------------
2259 // ciTypeFlow::flow_block
2260 //
2261 // Interpret the effects of the bytecodes on the incoming state
2262 // vector of a basic block. Push the changed state to succeeding
2263 // basic blocks.
2264 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2265 ciTypeFlow::StateVector* state,
2266 ciTypeFlow::JsrSet* jsrs) {
2267 if (CITraceTypeFlow) {
2268 tty->print("\n>> ANALYZING BLOCK : ");
2269 tty->cr();
2270 block->print_on(tty);
2271 }
2272 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2273
2274 int start = block->start();
2275 int limit = block->limit();
2276 int control = block->control();
2277 if (control != ciBlock::fall_through_bci) {
2278 limit = control;
2279 }
2280
2281 // Grab the state from the current block.
2282 block->copy_state_into(state);
2283 state->def_locals()->clear();
2284
2285 GrowableArray<Block*>* exceptions = block->exceptions();
2286 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2287 bool has_exceptions = exceptions->length() > 0;
2288
2289 bool exceptions_used = false;
2290
2291 ciBytecodeStream str(method());
2292 str.reset_to_bci(start);
2293 Bytecodes::Code code;
2294 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2295 str.cur_bci() < limit) {
2296 // Check for exceptional control flow from this point.
2297 if (has_exceptions && can_trap(str)) {
2298 flow_exceptions(exceptions, exc_klasses, state);
2299 exceptions_used = true;
2300 }
2301 // Apply the effects of the current bytecode to our state.
2302 bool res = state->apply_one_bytecode(&str);
2303
2304 // Watch for bailouts.
2305 if (failing()) return;
2306
2307 if (res) {
2308
2309 // We have encountered a trap. Record it in this block.
2310 block->set_trap(state->trap_bci(), state->trap_index());
2311
2312 if (CITraceTypeFlow) {
2313 tty->print_cr(">> Found trap");
2314 block->print_on(tty);
2315 }
2316
2317 // Save set of locals defined in this block
2318 block->def_locals()->add(state->def_locals());
2319
2320 // Record (no) successors.
2321 block->successors(&str, state, jsrs);
2322
2323 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2324
2325 // Discontinue interpretation of this Block.
2326 return;
2327 }
2328 }
2329
2330 GrowableArray<Block*>* successors = NULL;
2331 if (control != ciBlock::fall_through_bci) {
2332 // Check for exceptional control flow from this point.
2333 if (has_exceptions && can_trap(str)) {
2334 flow_exceptions(exceptions, exc_klasses, state);
2335 exceptions_used = true;
2336 }
2337
2338 // Fix the JsrSet to reflect effect of the bytecode.
2339 block->copy_jsrs_into(jsrs);
2340 jsrs->apply_control(this, &str, state);
2341
2342 // Find successor edges based on old state and new JsrSet.
2343 successors = block->successors(&str, state, jsrs);
2344
2345 // Apply the control changes to the state.
2346 state->apply_one_bytecode(&str);
2347 } else {
2348 // Fall through control
2349 successors = block->successors(&str, NULL, NULL);
2350 }
2351
2352 // Save set of locals defined in this block
2353 block->def_locals()->add(state->def_locals());
2354
2355 // Remove untaken exception paths
2356 if (!exceptions_used)
2357 exceptions->clear();
2358
2359 // Pass our state to successors.
2360 flow_successors(successors, state);
2361 }
2362
2363 // ------------------------------------------------------------------
2364 // ciTypeFlow::PostOrderLoops::next
2365 //
2366 // Advance to next loop tree using a postorder, left-to-right traversal.
2367 void ciTypeFlow::PostorderLoops::next() {
2368 assert(!done(), "must not be done.");
2369 if (_current->sibling() != NULL) {
2370 _current = _current->sibling();
2371 while (_current->child() != NULL) {
2372 _current = _current->child();
2373 }
2374 } else {
2375 _current = _current->parent();
2376 }
2377 }
2378
2379 // ------------------------------------------------------------------
2380 // ciTypeFlow::PreOrderLoops::next
2381 //
2382 // Advance to next loop tree using a preorder, left-to-right traversal.
2383 void ciTypeFlow::PreorderLoops::next() {
2384 assert(!done(), "must not be done.");
2385 if (_current->child() != NULL) {
2386 _current = _current->child();
2387 } else if (_current->sibling() != NULL) {
2388 _current = _current->sibling();
2389 } else {
2390 while (_current != _root && _current->sibling() == NULL) {
2391 _current = _current->parent();
2392 }
2393 if (_current == _root) {
2394 _current = NULL;
2395 assert(done(), "must be done.");
2396 } else {
2397 assert(_current->sibling() != NULL, "must be more to do");
2398 _current = _current->sibling();
2399 }
2400 }
2401 }
2402
2403 // ------------------------------------------------------------------
2404 // ciTypeFlow::Loop::sorted_merge
2405 //
2406 // Merge the branch lp into this branch, sorting on the loop head
2407 // pre_orders. Returns the leaf of the merged branch.
2408 // Child and sibling pointers will be setup later.
2409 // Sort is (looking from leaf towards the root)
2410 // descending on primary key: loop head's pre_order, and
2411 // ascending on secondary key: loop tail's pre_order.
2412 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2413 Loop* leaf = this;
2414 Loop* prev = NULL;
2415 Loop* current = leaf;
2416 while (lp != NULL) {
2417 int lp_pre_order = lp->head()->pre_order();
2418 // Find insertion point for "lp"
2419 while (current != NULL) {
2420 if (current == lp)
2421 return leaf; // Already in list
2422 if (current->head()->pre_order() < lp_pre_order)
2423 break;
2424 if (current->head()->pre_order() == lp_pre_order &&
2425 current->tail()->pre_order() > lp->tail()->pre_order()) {
2426 break;
2427 }
2428 prev = current;
2429 current = current->parent();
2430 }
2431 Loop* next_lp = lp->parent(); // Save future list of items to insert
2432 // Insert lp before current
2433 lp->set_parent(current);
2434 if (prev != NULL) {
2435 prev->set_parent(lp);
2436 } else {
2437 leaf = lp;
2438 }
2439 prev = lp; // Inserted item is new prev[ious]
2440 lp = next_lp; // Next item to insert
2441 }
2442 return leaf;
2443 }
2444
2445 // ------------------------------------------------------------------
2446 // ciTypeFlow::build_loop_tree
2447 //
2448 // Incrementally build loop tree.
2449 void ciTypeFlow::build_loop_tree(Block* blk) {
2450 assert(!blk->is_post_visited(), "precondition");
2451 Loop* innermost = NULL; // merge of loop tree branches over all successors
2452
2453 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2454 Loop* lp = NULL;
2455 Block* succ = iter.succ();
2456 if (!succ->is_post_visited()) {
2457 // Found backedge since predecessor post visited, but successor is not
2458 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2459
2460 // Create a LoopNode to mark this loop.
2461 lp = new (arena()) Loop(succ, blk);
2462 if (succ->loop() == NULL)
2463 succ->set_loop(lp);
2464 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2465
2466 } else { // Nested loop
2467 lp = succ->loop();
2468
2469 // If succ is loop head, find outer loop.
2470 while (lp != NULL && lp->head() == succ) {
2471 lp = lp->parent();
2472 }
2473 if (lp == NULL) {
2474 // Infinite loop, it's parent is the root
2475 lp = loop_tree_root();
2476 }
2477 }
2478
2479 // Check for irreducible loop.
2480 // Successor has already been visited. If the successor's loop head
2481 // has already been post-visited, then this is another entry into the loop.
2482 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2483 _has_irreducible_entry = true;
2484 lp->set_irreducible(succ);
2485 if (!succ->is_on_work_list()) {
2486 // Assume irreducible entries need more data flow
2487 add_to_work_list(succ);
2488 }
2489 Loop* plp = lp->parent();
2490 if (plp == NULL) {
2491 // This only happens for some irreducible cases. The parent
2492 // will be updated during a later pass.
2493 break;
2494 }
2495 lp = plp;
2496 }
2497
2498 // Merge loop tree branch for all successors.
2499 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2500
2501 } // end loop
2502
2503 if (innermost == NULL) {
2504 assert(blk->successors()->length() == 0, "CFG exit");
2505 blk->set_loop(loop_tree_root());
2506 } else if (innermost->head() == blk) {
2507 // If loop header, complete the tree pointers
2508 if (blk->loop() != innermost) {
2509 #if ASSERT
2510 assert(blk->loop()->head() == innermost->head(), "same head");
2511 Loop* dl;
2512 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2513 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2514 #endif
2515 blk->set_loop(innermost);
2516 }
2517 innermost->def_locals()->add(blk->def_locals());
2518 Loop* l = innermost;
2519 Loop* p = l->parent();
2520 while (p && l->head() == blk) {
2521 l->set_sibling(p->child()); // Put self on parents 'next child'
2522 p->set_child(l); // Make self the first child of parent
2523 p->def_locals()->add(l->def_locals());
2524 l = p; // Walk up the parent chain
2525 p = l->parent();
2526 }
2527 } else {
2528 blk->set_loop(innermost);
2529 innermost->def_locals()->add(blk->def_locals());
2530 }
2531 }
2532
2533 // ------------------------------------------------------------------
2534 // ciTypeFlow::Loop::contains
2535 //
2536 // Returns true if lp is nested loop.
2537 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2538 assert(lp != NULL, "");
2539 if (this == lp || head() == lp->head()) return true;
2540 int depth1 = depth();
2541 int depth2 = lp->depth();
2542 if (depth1 > depth2)
2543 return false;
2544 while (depth1 < depth2) {
2545 depth2--;
2546 lp = lp->parent();
2547 }
2548 return this == lp;
2549 }
2550
2551 // ------------------------------------------------------------------
2552 // ciTypeFlow::Loop::depth
2553 //
2554 // Loop depth
2555 int ciTypeFlow::Loop::depth() const {
2556 int dp = 0;
2557 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2558 dp++;
2559 return dp;
2560 }
2561
2562 #ifndef PRODUCT
2563 // ------------------------------------------------------------------
2564 // ciTypeFlow::Loop::print
2565 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2566 for (int i = 0; i < indent; i++) st->print(" ");
2567 st->print("%d<-%d %s",
2568 is_root() ? 0 : this->head()->pre_order(),
2569 is_root() ? 0 : this->tail()->pre_order(),
2570 is_irreducible()?" irr":"");
2571 st->print(" defs: ");
2572 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2573 st->cr();
2574 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2575 ch->print(st, indent+2);
2576 }
2577 #endif
2578
2579 // ------------------------------------------------------------------
2580 // ciTypeFlow::df_flow_types
2581 //
2582 // Perform the depth first type flow analysis. Helper for flow_types.
2583 void ciTypeFlow::df_flow_types(Block* start,
2584 bool do_flow,
2585 StateVector* temp_vector,
2586 JsrSet* temp_set) {
2587 int dft_len = 100;
2588 GrowableArray<Block*> stk(arena(), dft_len, 0, NULL);
2589
2590 ciBlock* dummy = _methodBlocks->make_dummy_block();
2591 JsrSet* root_set = new JsrSet(NULL, 0);
2592 Block* root_head = new (arena()) Block(this, dummy, root_set);
2593 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2594 root_head->set_pre_order(0);
2595 root_head->set_post_order(0);
2596 root_tail->set_pre_order(max_jint);
2597 root_tail->set_post_order(max_jint);
2598 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2599
2600 stk.push(start);
2601
2602 _next_pre_order = 0; // initialize pre_order counter
2603 _rpo_list = NULL;
2604 int next_po = 0; // initialize post_order counter
2605
2606 // Compute RPO and the control flow graph
2607 int size;
2608 while ((size = stk.length()) > 0) {
2609 Block* blk = stk.top(); // Leave node on stack
2610 if (!blk->is_visited()) {
2611 // forward arc in graph
2612 assert (!blk->has_pre_order(), "");
2613 blk->set_next_pre_order();
2614
2615 if (_next_pre_order >= MaxNodeLimit / 2) {
2616 // Too many basic blocks. Bail out.
2617 // This can happen when try/finally constructs are nested to depth N,
2618 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2619 // "MaxNodeLimit / 2" is used because probably the parser will
2620 // generate at least twice that many nodes and bail out.
2621 record_failure("too many basic blocks");
2622 return;
2623 }
2624 if (do_flow) {
2625 flow_block(blk, temp_vector, temp_set);
2626 if (failing()) return; // Watch for bailouts.
2627 }
2628 } else if (!blk->is_post_visited()) {
2629 // cross or back arc
2630 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2631 Block* succ = iter.succ();
2632 if (!succ->is_visited()) {
2633 stk.push(succ);
2634 }
2635 }
2636 if (stk.length() == size) {
2637 // There were no additional children, post visit node now
2638 stk.pop(); // Remove node from stack
2639
2640 build_loop_tree(blk);
2641 blk->set_post_order(next_po++); // Assign post order
2642 prepend_to_rpo_list(blk);
2643 assert(blk->is_post_visited(), "");
2644
2645 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2646 // Assume loop heads need more data flow
2647 add_to_work_list(blk);
2648 }
2649 }
2650 } else {
2651 stk.pop(); // Remove post-visited node from stack
2652 }
2653 }
2654 }
2655
2656 // ------------------------------------------------------------------
2657 // ciTypeFlow::flow_types
2658 //
2659 // Perform the type flow analysis, creating and cloning Blocks as
2660 // necessary.
2661 void ciTypeFlow::flow_types() {
2662 ResourceMark rm;
2663 StateVector* temp_vector = new StateVector(this);
2664 JsrSet* temp_set = new JsrSet(NULL, 16);
2665
2666 // Create the method entry block.
2667 Block* start = block_at(start_bci(), temp_set);
2668
2669 // Load the initial state into it.
2670 const StateVector* start_state = get_start_state();
2671 if (failing()) return;
2672 start->meet(start_state);
2673
2674 // Depth first visit
2675 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2676
2677 if (failing()) return;
2678 assert(_rpo_list == start, "must be start");
2679
2680 // Any loops found?
2681 if (loop_tree_root()->child() != NULL &&
2682 env()->comp_level() >= CompLevel_full_optimization) {
2683 // Loop optimizations are not performed on Tier1 compiles.
2684
2685 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2686
2687 // If some loop heads were cloned, recompute postorder and loop tree
2688 if (changed) {
2689 loop_tree_root()->set_child(NULL);
2690 for (Block* blk = _rpo_list; blk != NULL;) {
2691 Block* next = blk->rpo_next();
2692 blk->df_init();
2693 blk = next;
2694 }
2695 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2696 }
2697 }
2698
2699 if (CITraceTypeFlow) {
2700 tty->print_cr("\nLoop tree");
2701 loop_tree_root()->print();
2702 }
2703
2704 // Continue flow analysis until fixed point reached
2705
2706 debug_only(int max_block = _next_pre_order;)
2707
2708 while (!work_list_empty()) {
2709 Block* blk = work_list_next();
2710 assert (blk->has_post_order(), "post order assigned above");
2711
2712 flow_block(blk, temp_vector, temp_set);
2713
2714 assert (max_block == _next_pre_order, "no new blocks");
2715 assert (!failing(), "no more bailouts");
2716 }
2717 }
2718
2719 // ------------------------------------------------------------------
2720 // ciTypeFlow::map_blocks
2721 //
2722 // Create the block map, which indexes blocks in reverse post-order.
2723 void ciTypeFlow::map_blocks() {
2724 assert(_block_map == NULL, "single initialization");
2725 int block_ct = _next_pre_order;
2726 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2727 assert(block_ct == block_count(), "");
2728
2729 Block* blk = _rpo_list;
2730 for (int m = 0; m < block_ct; m++) {
2731 int rpo = blk->rpo();
2732 assert(rpo == m, "should be sequential");
2733 _block_map[rpo] = blk;
2734 blk = blk->rpo_next();
2735 }
2736 assert(blk == NULL, "should be done");
2737
2738 for (int j = 0; j < block_ct; j++) {
2739 assert(_block_map[j] != NULL, "must not drop any blocks");
2740 Block* block = _block_map[j];
2741 // Remove dead blocks from successor lists:
2742 for (int e = 0; e <= 1; e++) {
2743 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2744 for (int k = 0; k < l->length(); k++) {
2745 Block* s = l->at(k);
2746 if (!s->has_post_order()) {
2747 if (CITraceTypeFlow) {
2748 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2749 s->print_value_on(tty);
2750 tty->cr();
2751 }
2752 l->remove(s);
2753 --k;
2754 }
2755 }
2756 }
2757 }
2758 }
2759
2760 // ------------------------------------------------------------------
2761 // ciTypeFlow::get_block_for
2762 //
2763 // Find a block with this ciBlock which has a compatible JsrSet.
2764 // If no such block exists, create it, unless the option is no_create.
2765 // If the option is create_backedge_copy, always create a fresh backedge copy.
2766 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2767 Arena* a = arena();
2768 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2769 if (blocks == NULL) {
2770 // Query only?
2771 if (option == no_create) return NULL;
2772
2773 // Allocate the growable array.
2774 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2775 _idx_to_blocklist[ciBlockIndex] = blocks;
2776 }
2777
2778 if (option != create_backedge_copy) {
2779 int len = blocks->length();
2780 for (int i = 0; i < len; i++) {
2781 Block* block = blocks->at(i);
2782 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2783 return block;
2784 }
2785 }
2786 }
2787
2788 // Query only?
2789 if (option == no_create) return NULL;
2790
2791 // We did not find a compatible block. Create one.
2792 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2793 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2794 blocks->append(new_block);
2795 return new_block;
2796 }
2797
2798 // ------------------------------------------------------------------
2799 // ciTypeFlow::backedge_copy_count
2800 //
2801 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2802 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2803
2804 if (blocks == NULL) {
2805 return 0;
2806 }
2807
2808 int count = 0;
2809 int len = blocks->length();
2810 for (int i = 0; i < len; i++) {
2811 Block* block = blocks->at(i);
2812 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2813 count++;
2814 }
2815 }
2816
2817 return count;
2818 }
2819
2820 // ------------------------------------------------------------------
2821 // ciTypeFlow::do_flow
2822 //
2823 // Perform type inference flow analysis.
2824 void ciTypeFlow::do_flow() {
2825 if (CITraceTypeFlow) {
2826 tty->print_cr("\nPerforming flow analysis on method");
2827 method()->print();
2828 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2829 tty->cr();
2830 method()->print_codes();
2831 }
2832 if (CITraceTypeFlow) {
2833 tty->print_cr("Initial CI Blocks");
2834 print_on(tty);
2835 }
2836 flow_types();
2837 // Watch for bailouts.
2838 if (failing()) {
2839 return;
2840 }
2841
2842 map_blocks();
2843
2844 if (CIPrintTypeFlow || CITraceTypeFlow) {
2845 rpo_print_on(tty);
2846 }
2847 }
2848
2849 // ------------------------------------------------------------------
2850 // ciTypeFlow::record_failure()
2851 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
2852 // This is required because there is not a 1-1 relation between the ciEnv and
2853 // the TypeFlow passes within a compilation task. For example, if the compiler
2854 // is considering inlining a method, it will request a TypeFlow. If that fails,
2855 // the compilation as a whole may continue without the inlining. Some TypeFlow
2856 // requests are not optional; if they fail the requestor is responsible for
2857 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
2858 void ciTypeFlow::record_failure(const char* reason) {
2859 if (env()->log() != NULL) {
2860 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
2861 }
2862 if (_failure_reason == NULL) {
2863 // Record the first failure reason.
2864 _failure_reason = reason;
2865 }
2866 }
2867
2868 #ifndef PRODUCT
2869 // ------------------------------------------------------------------
2870 // ciTypeFlow::print_on
2871 void ciTypeFlow::print_on(outputStream* st) const {
2872 // Walk through CI blocks
2873 st->print_cr("********************************************************");
2874 st->print ("TypeFlow for ");
2875 method()->name()->print_symbol_on(st);
2876 int limit_bci = code_size();
2877 st->print_cr(" %d bytes", limit_bci);
2878 ciMethodBlocks *mblks = _methodBlocks;
2879 ciBlock* current = NULL;
2880 for (int bci = 0; bci < limit_bci; bci++) {
2881 ciBlock* blk = mblks->block_containing(bci);
2882 if (blk != NULL && blk != current) {
2883 current = blk;
2884 current->print_on(st);
2885
2886 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
2887 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
2888
2889 if (num_blocks == 0) {
2890 st->print_cr(" No Blocks");
2891 } else {
2892 for (int i = 0; i < num_blocks; i++) {
2893 Block* block = blocks->at(i);
2894 block->print_on(st);
2895 }
2896 }
2897 st->print_cr("--------------------------------------------------------");
2898 st->cr();
2899 }
2900 }
2901 st->print_cr("********************************************************");
2902 st->cr();
2903 }
2904
2905 void ciTypeFlow::rpo_print_on(outputStream* st) const {
2906 st->print_cr("********************************************************");
2907 st->print ("TypeFlow for ");
2908 method()->name()->print_symbol_on(st);
2909 int limit_bci = code_size();
2910 st->print_cr(" %d bytes", limit_bci);
2911 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
2912 blk->print_on(st);
2913 st->print_cr("--------------------------------------------------------");
2914 st->cr();
2915 }
2916 st->print_cr("********************************************************");
2917 st->cr();
2918 }
2919 #endif