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
217 // ------------------------------------------------------------------
218 // ciTypeFlow::JsrSet::apply_state
219 // remove any JsrRecords which refer to address that aren't in state
220 void ciTypeFlow::JsrSet::apply_state(StateVector* state) {
221 int len = size();
222 for (int i = 0; i < len; i++) {
223 int ra = record_at(i)->return_address();
224 bool found = false;
225 Cell limit = state->limit_cell();
226 for (Cell c = state->start_cell(); c < limit; c = state->next_cell(c)) {
227 ciType* cell_type = state->type_at(c);
228 if (cell_type->is_return_address() && cell_type->as_return_address()->bci() == ra) {
229 found = true;
230 break;
231 }
232 }
233 if (!found) {
234 remove_jsr_record(ra);
235 i--;
236 len--;
237 }
238 }
239 }
240
241
242
243 #ifndef PRODUCT
244 // ------------------------------------------------------------------
245 // ciTypeFlow::JsrSet::print_on
246 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
247 st->print("{ ");
248 int num_elements = size();
249 if (num_elements > 0) {
250 int i = 0;
251 for( ; i < num_elements - 1; i++) {
252 _set->at(i)->print_on(st);
253 st->print(", ");
254 }
255 _set->at(i)->print_on(st);
256 st->print(" ");
257 }
258 st->print("}");
259 }
260 #endif
261
262 // ciTypeFlow::StateVector
263 //
264 // A StateVector summarizes the type information at some point in
265 // the program.
266
267 // ------------------------------------------------------------------
268 // ciTypeFlow::StateVector::type_meet
269 //
270 // Meet two types.
271 //
272 // The semi-lattice of types use by this analysis are modeled on those
273 // of the verifier. The lattice is as follows:
274 //
275 // top_type() >= all non-extremal types >= bottom_type
276 // and
277 // Every primitive type is comparable only with itself. The meet of
278 // reference types is determined by their kind: instance class,
279 // interface, or array class. The meet of two types of the same
280 // kind is their least common ancestor. The meet of two types of
281 // different kinds is always java.lang.Object.
282 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
283 assert(t1 != t2, "checked in caller");
284 if (t1->equals(top_type())) {
285 return t2;
286 } else if (t2->equals(top_type())) {
287 return t1;
288 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
289 // Special case null_type. null_type meet any reference type T
290 // is T. null_type meet null_type is null_type.
291 if (t1->equals(null_type())) {
292 if (!t2->is_primitive_type() || t2->equals(null_type())) {
293 return t2;
294 }
295 } else if (t2->equals(null_type())) {
296 if (!t1->is_primitive_type()) {
297 return t1;
298 }
299 }
300
301 // At least one of the two types is a non-top primitive type.
302 // The other type is not equal to it. Fall to bottom.
303 return bottom_type();
304 } else {
305 // Both types are non-top non-primitive types. That is,
306 // both types are either instanceKlasses or arrayKlasses.
307 ciKlass* object_klass = analyzer->env()->Object_klass();
308 ciKlass* k1 = t1->as_klass();
309 ciKlass* k2 = t2->as_klass();
310 if (k1->equals(object_klass) || k2->equals(object_klass)) {
311 return object_klass;
312 } else if (!k1->is_loaded() || !k2->is_loaded()) {
313 // Unloaded classes fall to java.lang.Object at a merge.
314 return object_klass;
315 } else if (k1->is_interface() != k2->is_interface()) {
316 // When an interface meets a non-interface, we get Object;
317 // This is what the verifier does.
318 return object_klass;
319 } else if (k1->is_array_klass() || k2->is_array_klass()) {
320 // When an array meets a non-array, we get Object.
321 // When objArray meets typeArray, we also get Object.
322 // And when typeArray meets different typeArray, we again get Object.
323 // But when objArray meets objArray, we look carefully at element types.
324 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
325 // Meet the element types, then construct the corresponding array type.
326 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
327 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
328 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
329 // Do an easy shortcut if one type is a super of the other.
330 if (elem == elem1) {
331 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
332 return k1;
333 } else if (elem == elem2) {
334 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
335 return k2;
336 } else {
337 return ciObjArrayKlass::make(elem);
338 }
339 } else {
340 return object_klass;
341 }
342 } else {
343 // Must be two plain old instance klasses.
344 assert(k1->is_instance_klass(), "previous cases handle non-instances");
345 assert(k2->is_instance_klass(), "previous cases handle non-instances");
346 return k1->least_common_ancestor(k2);
347 }
348 }
349 }
350
351
352 // ------------------------------------------------------------------
353 // ciTypeFlow::StateVector::StateVector
354 //
355 // Build a new state vector
356 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
357 _outer = analyzer;
358 _stack_size = -1;
359 _monitor_count = -1;
360 // Allocate the _types array
361 int max_cells = analyzer->max_cells();
362 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
363 for (int i=0; i<max_cells; i++) {
364 _types[i] = top_type();
365 }
366 _trap_bci = -1;
367 _trap_index = 0;
368 _def_locals.clear();
369 }
370
371
372 // ------------------------------------------------------------------
373 // ciTypeFlow::get_start_state
374 //
375 // Set this vector to the method entry state.
376 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
377 StateVector* state = new StateVector(this);
378 if (is_osr_flow()) {
379 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
380 if (non_osr_flow->failing()) {
381 record_failure(non_osr_flow->failure_reason());
382 return NULL;
383 }
384 JsrSet* jsrs = new JsrSet(NULL, 16);
385 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
386 if (non_osr_block == NULL) {
387 record_failure("cannot reach OSR point");
388 return NULL;
389 }
390 // load up the non-OSR state at this point
391 non_osr_block->copy_state_into(state);
392 int non_osr_start = non_osr_block->start();
393 if (non_osr_start != start_bci()) {
394 // must flow forward from it
395 if (CITraceTypeFlow) {
396 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
397 }
398 Block* block = block_at(non_osr_start, jsrs);
399 assert(block->limit() == start_bci(), "must flow forward to start");
400 flow_block(block, state, jsrs);
401 }
402 return state;
403 // Note: The code below would be an incorrect for an OSR flow,
404 // even if it were possible for an OSR entry point to be at bci zero.
405 }
406 // "Push" the method signature into the first few locals.
407 state->set_stack_size(-max_locals());
408 if (!method()->is_static()) {
409 state->push(method()->holder());
410 assert(state->tos() == state->local(0), "");
411 }
412 for (ciSignatureStream str(method()->signature());
413 !str.at_return_type();
414 str.next()) {
415 state->push_translate(str.type());
416 }
417 // Set the rest of the locals to bottom.
418 Cell cell = state->next_cell(state->tos());
419 state->set_stack_size(0);
420 int limit = state->limit_cell();
421 for (; cell < limit; cell = state->next_cell(cell)) {
422 state->set_type_at(cell, state->bottom_type());
423 }
424 // Lock an object, if necessary.
425 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
426 return state;
427 }
428
429 // ------------------------------------------------------------------
430 // ciTypeFlow::StateVector::copy_into
431 //
432 // Copy our value into some other StateVector
433 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
434 const {
435 copy->set_stack_size(stack_size());
436 copy->set_monitor_count(monitor_count());
437 Cell limit = limit_cell();
438 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
439 copy->set_type_at(c, type_at(c));
440 }
441 }
442
443 // ------------------------------------------------------------------
444 // ciTypeFlow::StateVector::meet
445 //
446 // Meets this StateVector with another, destructively modifying this
447 // one. Returns true if any modification takes place.
448 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
449 if (monitor_count() == -1) {
450 set_monitor_count(incoming->monitor_count());
451 }
452 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
453
454 if (stack_size() == -1) {
455 set_stack_size(incoming->stack_size());
456 Cell limit = limit_cell();
457 #ifdef ASSERT
458 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
459 assert(type_at(c) == top_type(), "");
460 } }
461 #endif
462 // Make a simple copy of the incoming state.
463 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
464 set_type_at(c, incoming->type_at(c));
465 }
466 return true; // it is always different the first time
467 }
468 #ifdef ASSERT
469 if (stack_size() != incoming->stack_size()) {
470 _outer->method()->print_codes();
471 tty->print_cr("!!!! Stack size conflict");
472 tty->print_cr("Current state:");
473 print_on(tty);
474 tty->print_cr("Incoming state:");
475 ((StateVector*)incoming)->print_on(tty);
476 }
477 #endif
478 assert(stack_size() == incoming->stack_size(), "sanity");
479
480 bool different = false;
481 Cell limit = limit_cell();
482 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
483 ciType* t1 = type_at(c);
484 ciType* t2 = incoming->type_at(c);
485 if (!t1->equals(t2)) {
486 ciType* new_type = type_meet(t1, t2);
487 if (!t1->equals(new_type)) {
488 set_type_at(c, new_type);
489 different = true;
490 }
491 }
492 }
493 return different;
494 }
495
496 // ------------------------------------------------------------------
497 // ciTypeFlow::StateVector::meet_exception
498 //
499 // Meets this StateVector with another, destructively modifying this
500 // one. The incoming state is coming via an exception. Returns true
501 // if any modification takes place.
502 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
503 const ciTypeFlow::StateVector* incoming) {
504 if (monitor_count() == -1) {
505 set_monitor_count(incoming->monitor_count());
506 }
507 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
508
509 if (stack_size() == -1) {
510 set_stack_size(1);
511 }
512
513 assert(stack_size() == 1, "must have one-element stack");
514
515 bool different = false;
516
517 // Meet locals from incoming array.
518 Cell limit = local(_outer->max_locals()-1);
519 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
520 ciType* t1 = type_at(c);
521 ciType* t2 = incoming->type_at(c);
522 if (!t1->equals(t2)) {
523 ciType* new_type = type_meet(t1, t2);
524 if (!t1->equals(new_type)) {
525 set_type_at(c, new_type);
526 different = true;
527 }
528 }
529 }
530
531 // Handle stack separately. When an exception occurs, the
532 // only stack entry is the exception instance.
533 ciType* tos_type = type_at_tos();
534 if (!tos_type->equals(exc)) {
535 ciType* new_type = type_meet(tos_type, exc);
536 if (!tos_type->equals(new_type)) {
537 set_type_at_tos(new_type);
538 different = true;
539 }
540 }
541
542 return different;
543 }
544
545 // ------------------------------------------------------------------
546 // ciTypeFlow::StateVector::push_translate
547 void ciTypeFlow::StateVector::push_translate(ciType* type) {
548 BasicType basic_type = type->basic_type();
549 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
550 basic_type == T_BYTE || basic_type == T_SHORT) {
551 push_int();
552 } else {
553 push(type);
554 if (type->is_two_word()) {
555 push(half_type(type));
556 }
557 }
558 }
559
560 // ------------------------------------------------------------------
561 // ciTypeFlow::StateVector::do_aaload
562 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) {
563 pop_int();
564 ciObjArrayKlass* array_klass = pop_objArray();
565 if (array_klass == NULL) {
566 // Did aaload on a null reference; push a null and ignore the exception.
567 // This instruction will never continue normally. All we have to do
568 // is report a value that will meet correctly with any downstream
569 // reference types on paths that will truly be executed. This null type
570 // meets with any reference type to yield that same reference type.
571 // (The compiler will generate an unconditional exception here.)
572 push(null_type());
573 return;
574 }
575 if (!array_klass->is_loaded()) {
576 // Only fails for some -Xcomp runs
577 trap(str, array_klass,
578 Deoptimization::make_trap_request
579 (Deoptimization::Reason_unloaded,
580 Deoptimization::Action_reinterpret));
581 return;
582 }
583 ciKlass* element_klass = array_klass->element_klass();
584 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
585 Untested("unloaded array element class in ciTypeFlow");
586 trap(str, element_klass,
587 Deoptimization::make_trap_request
588 (Deoptimization::Reason_unloaded,
589 Deoptimization::Action_reinterpret));
590 } else {
591 push_object(element_klass);
592 }
593 }
594
595
596 // ------------------------------------------------------------------
597 // ciTypeFlow::StateVector::do_checkcast
598 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
599 bool will_link;
600 ciKlass* klass = str->get_klass(will_link);
601 if (!will_link) {
602 // VM's interpreter will not load 'klass' if object is NULL.
603 // Type flow after this block may still be needed in two situations:
604 // 1) C2 uses do_null_assert() and continues compilation for later blocks
605 // 2) C2 does an OSR compile in a later block (see bug 4778368).
606 pop_object();
607 do_null_assert(klass);
608 } else {
609 pop_object();
610 push_object(klass);
611 }
612 }
613
614 // ------------------------------------------------------------------
615 // ciTypeFlow::StateVector::do_getfield
616 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
617 // could add assert here for type of object.
618 pop_object();
619 do_getstatic(str);
620 }
621
622 // ------------------------------------------------------------------
623 // ciTypeFlow::StateVector::do_getstatic
624 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
625 bool will_link;
626 ciField* field = str->get_field(will_link);
627 if (!will_link) {
628 trap(str, field->holder(), str->get_field_holder_index());
629 } else {
630 ciType* field_type = field->type();
631 if (!field_type->is_loaded()) {
632 // Normally, we need the field's type to be loaded if we are to
633 // do anything interesting with its value.
634 // We used to do this: trap(str, str->get_field_signature_index());
635 //
636 // There is one good reason not to trap here. Execution can
637 // get past this "getfield" or "getstatic" if the value of
638 // the field is null. As long as the value is null, the class
639 // does not need to be loaded! The compiler must assume that
640 // the value of the unloaded class reference is null; if the code
641 // ever sees a non-null value, loading has occurred.
642 //
643 // This actually happens often enough to be annoying. If the
644 // compiler throws an uncommon trap at this bytecode, you can
645 // get an endless loop of recompilations, when all the code
646 // needs to do is load a series of null values. Also, a trap
647 // here can make an OSR entry point unreachable, triggering the
648 // assert on non_osr_block in ciTypeFlow::get_start_state.
649 // (See bug 4379915.)
650 do_null_assert(field_type->as_klass());
651 } else {
652 push_translate(field_type);
653 }
654 }
655 }
656
657 // ------------------------------------------------------------------
658 // ciTypeFlow::StateVector::do_invoke
659 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
660 bool has_receiver) {
661 bool will_link;
662 ciMethod* method = str->get_method(will_link);
663 if (!will_link) {
664 // We weren't able to find the method.
665 ciKlass* unloaded_holder = method->holder();
666 trap(str, unloaded_holder, str->get_method_holder_index());
667 } else {
668 ciSignature* signature = method->signature();
669 ciSignatureStream sigstr(signature);
670 int arg_size = signature->size();
671 int stack_base = stack_size() - arg_size;
672 int i = 0;
673 for( ; !sigstr.at_return_type(); sigstr.next()) {
674 ciType* type = sigstr.type();
675 ciType* stack_type = type_at(stack(stack_base + i++));
676 // Do I want to check this type?
677 // assert(stack_type->is_subtype_of(type), "bad type for field value");
678 if (type->is_two_word()) {
679 ciType* stack_type2 = type_at(stack(stack_base + i++));
680 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
681 }
682 }
683 assert(arg_size == i, "must match");
684 for (int j = 0; j < arg_size; j++) {
685 pop();
686 }
687 if (has_receiver) {
688 // Check this?
689 pop_object();
690 }
691 assert(!sigstr.is_done(), "must have return type");
692 ciType* return_type = sigstr.type();
693 if (!return_type->is_void()) {
694 if (!return_type->is_loaded()) {
695 // As in do_getstatic(), generally speaking, we need the return type to
696 // be loaded if we are to do anything interesting with its value.
697 // We used to do this: trap(str, str->get_method_signature_index());
698 //
699 // We do not trap here since execution can get past this invoke if
700 // the return value is null. As long as the value is null, the class
701 // does not need to be loaded! The compiler must assume that
702 // the value of the unloaded class reference is null; if the code
703 // ever sees a non-null value, loading has occurred.
704 //
705 // See do_getstatic() for similar explanation, as well as bug 4684993.
706 do_null_assert(return_type->as_klass());
707 } else {
708 push_translate(return_type);
709 }
710 }
711 }
712 }
713
714 // ------------------------------------------------------------------
715 // ciTypeFlow::StateVector::do_jsr
716 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
717 push(ciReturnAddress::make(str->next_bci()));
718 }
719
720 // ------------------------------------------------------------------
721 // ciTypeFlow::StateVector::do_ldc
722 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
723 ciConstant con = str->get_constant();
724 BasicType basic_type = con.basic_type();
725 if (basic_type == T_ILLEGAL) {
726 // OutOfMemoryError in the CI while loading constant
727 push_null();
728 outer()->record_failure("ldc did not link");
729 return;
730 }
731 if (basic_type == T_OBJECT || basic_type == T_ARRAY) {
732 ciObject* obj = con.as_object();
733 if (obj->is_null_object()) {
734 push_null();
735 } else if (obj->is_klass()) {
736 // The type of ldc <class> is java.lang.Class
737 push_object(outer()->env()->Class_klass());
738 } else {
739 push_object(obj->klass());
740 }
741 } else {
742 push_translate(ciType::make(basic_type));
743 }
744 }
745
746 // ------------------------------------------------------------------
747 // ciTypeFlow::StateVector::do_multianewarray
748 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
749 int dimensions = str->get_dimensions();
750 bool will_link;
751 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
752 if (!will_link) {
753 trap(str, array_klass, str->get_klass_index());
754 } else {
755 for (int i = 0; i < dimensions; i++) {
756 pop_int();
757 }
758 push_object(array_klass);
759 }
760 }
761
762 // ------------------------------------------------------------------
763 // ciTypeFlow::StateVector::do_new
764 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
765 bool will_link;
766 ciKlass* klass = str->get_klass(will_link);
767 if (!will_link || str->is_unresolved_klass()) {
768 trap(str, klass, str->get_klass_index());
769 } else {
770 push_object(klass);
771 }
772 }
773
774 // ------------------------------------------------------------------
775 // ciTypeFlow::StateVector::do_newarray
776 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
777 pop_int();
778 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
779 push_object(klass);
780 }
781
782 // ------------------------------------------------------------------
783 // ciTypeFlow::StateVector::do_putfield
784 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
785 do_putstatic(str);
786 if (_trap_bci != -1) return; // unloaded field holder, etc.
787 // could add assert here for type of object.
788 pop_object();
789 }
790
791 // ------------------------------------------------------------------
792 // ciTypeFlow::StateVector::do_putstatic
793 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
794 bool will_link;
795 ciField* field = str->get_field(will_link);
796 if (!will_link) {
797 trap(str, field->holder(), str->get_field_holder_index());
798 } else {
799 ciType* field_type = field->type();
800 ciType* type = pop_value();
801 // Do I want to check this type?
802 // assert(type->is_subtype_of(field_type), "bad type for field value");
803 if (field_type->is_two_word()) {
804 ciType* type2 = pop_value();
805 assert(type2->is_two_word(), "must be 2nd half");
806 assert(type == half_type(type2), "must be 2nd half");
807 }
808 }
809 }
810
811 // ------------------------------------------------------------------
812 // ciTypeFlow::StateVector::do_ret
813 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
814 Cell index = local(str->get_index());
815
816 ciType* address = type_at(index);
817 assert(address->is_return_address(), "bad return address");
818 set_type_at(index, bottom_type());
819 }
820
821 // ------------------------------------------------------------------
822 // ciTypeFlow::StateVector::trap
823 //
824 // Stop interpretation of this path with a trap.
825 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
826 _trap_bci = str->cur_bci();
827 _trap_index = index;
828
829 // Log information about this trap:
830 CompileLog* log = outer()->env()->log();
831 if (log != NULL) {
832 int mid = log->identify(outer()->method());
833 int kid = (klass == NULL)? -1: log->identify(klass);
834 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
835 char buf[100];
836 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
837 index));
838 if (kid >= 0)
839 log->print(" klass='%d'", kid);
840 log->end_elem();
841 }
842 }
843
844 // ------------------------------------------------------------------
845 // ciTypeFlow::StateVector::do_null_assert
846 // Corresponds to graphKit::do_null_assert.
847 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
848 if (unloaded_klass->is_loaded()) {
849 // We failed to link, but we can still compute with this class,
850 // since it is loaded somewhere. The compiler will uncommon_trap
851 // if the object is not null, but the typeflow pass can not assume
852 // that the object will be null, otherwise it may incorrectly tell
853 // the parser that an object is known to be null. 4761344, 4807707
854 push_object(unloaded_klass);
855 } else {
856 // The class is not loaded anywhere. It is safe to model the
857 // null in the typestates, because we can compile in a null check
858 // which will deoptimize us if someone manages to load the
859 // class later.
860 push_null();
861 }
862 }
863
864
865 // ------------------------------------------------------------------
866 // ciTypeFlow::StateVector::apply_one_bytecode
867 //
868 // Apply the effect of one bytecode to this StateVector
869 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
870 _trap_bci = -1;
871 _trap_index = 0;
872
873 if (CITraceTypeFlow) {
874 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
875 Bytecodes::name(str->cur_bc()));
876 }
877
878 switch(str->cur_bc()) {
879 case Bytecodes::_aaload: do_aaload(str); break;
880
881 case Bytecodes::_aastore:
882 {
883 pop_object();
884 pop_int();
885 pop_objArray();
886 break;
887 }
888 case Bytecodes::_aconst_null:
889 {
890 push_null();
891 break;
892 }
893 case Bytecodes::_aload: load_local_object(str->get_index()); break;
894 case Bytecodes::_aload_0: load_local_object(0); break;
895 case Bytecodes::_aload_1: load_local_object(1); break;
896 case Bytecodes::_aload_2: load_local_object(2); break;
897 case Bytecodes::_aload_3: load_local_object(3); break;
898
899 case Bytecodes::_anewarray:
900 {
901 pop_int();
902 bool will_link;
903 ciKlass* element_klass = str->get_klass(will_link);
904 if (!will_link) {
905 trap(str, element_klass, str->get_klass_index());
906 } else {
907 push_object(ciObjArrayKlass::make(element_klass));
908 }
909 break;
910 }
911 case Bytecodes::_areturn:
912 case Bytecodes::_ifnonnull:
913 case Bytecodes::_ifnull:
914 {
915 pop_object();
916 break;
917 }
918 case Bytecodes::_monitorenter:
919 {
920 pop_object();
921 set_monitor_count(monitor_count() + 1);
922 break;
923 }
924 case Bytecodes::_monitorexit:
925 {
926 pop_object();
927 assert(monitor_count() > 0, "must be a monitor to exit from");
928 set_monitor_count(monitor_count() - 1);
929 break;
930 }
931 case Bytecodes::_arraylength:
932 {
933 pop_array();
934 push_int();
935 break;
936 }
937 case Bytecodes::_astore: store_local_object(str->get_index()); break;
938 case Bytecodes::_astore_0: store_local_object(0); break;
939 case Bytecodes::_astore_1: store_local_object(1); break;
940 case Bytecodes::_astore_2: store_local_object(2); break;
941 case Bytecodes::_astore_3: store_local_object(3); break;
942
943 case Bytecodes::_athrow:
944 {
945 NEEDS_CLEANUP;
946 pop_object();
947 break;
948 }
949 case Bytecodes::_baload:
950 case Bytecodes::_caload:
951 case Bytecodes::_iaload:
952 case Bytecodes::_saload:
953 {
954 pop_int();
955 ciTypeArrayKlass* array_klass = pop_typeArray();
956 // Put assert here for right type?
957 push_int();
958 break;
959 }
960 case Bytecodes::_bastore:
961 case Bytecodes::_castore:
962 case Bytecodes::_iastore:
963 case Bytecodes::_sastore:
964 {
965 pop_int();
966 pop_int();
967 pop_typeArray();
968 // assert here?
969 break;
970 }
971 case Bytecodes::_bipush:
972 case Bytecodes::_iconst_m1:
973 case Bytecodes::_iconst_0:
974 case Bytecodes::_iconst_1:
975 case Bytecodes::_iconst_2:
976 case Bytecodes::_iconst_3:
977 case Bytecodes::_iconst_4:
978 case Bytecodes::_iconst_5:
979 case Bytecodes::_sipush:
980 {
981 push_int();
982 break;
983 }
984 case Bytecodes::_checkcast: do_checkcast(str); break;
985
986 case Bytecodes::_d2f:
987 {
988 pop_double();
989 push_float();
990 break;
991 }
992 case Bytecodes::_d2i:
993 {
994 pop_double();
995 push_int();
996 break;
997 }
998 case Bytecodes::_d2l:
999 {
1000 pop_double();
1001 push_long();
1002 break;
1003 }
1004 case Bytecodes::_dadd:
1005 case Bytecodes::_ddiv:
1006 case Bytecodes::_dmul:
1007 case Bytecodes::_drem:
1008 case Bytecodes::_dsub:
1009 {
1010 pop_double();
1011 pop_double();
1012 push_double();
1013 break;
1014 }
1015 case Bytecodes::_daload:
1016 {
1017 pop_int();
1018 ciTypeArrayKlass* array_klass = pop_typeArray();
1019 // Put assert here for right type?
1020 push_double();
1021 break;
1022 }
1023 case Bytecodes::_dastore:
1024 {
1025 pop_double();
1026 pop_int();
1027 pop_typeArray();
1028 // assert here?
1029 break;
1030 }
1031 case Bytecodes::_dcmpg:
1032 case Bytecodes::_dcmpl:
1033 {
1034 pop_double();
1035 pop_double();
1036 push_int();
1037 break;
1038 }
1039 case Bytecodes::_dconst_0:
1040 case Bytecodes::_dconst_1:
1041 {
1042 push_double();
1043 break;
1044 }
1045 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1046 case Bytecodes::_dload_0: load_local_double(0); break;
1047 case Bytecodes::_dload_1: load_local_double(1); break;
1048 case Bytecodes::_dload_2: load_local_double(2); break;
1049 case Bytecodes::_dload_3: load_local_double(3); break;
1050
1051 case Bytecodes::_dneg:
1052 {
1053 pop_double();
1054 push_double();
1055 break;
1056 }
1057 case Bytecodes::_dreturn:
1058 {
1059 pop_double();
1060 break;
1061 }
1062 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1063 case Bytecodes::_dstore_0: store_local_double(0); break;
1064 case Bytecodes::_dstore_1: store_local_double(1); break;
1065 case Bytecodes::_dstore_2: store_local_double(2); break;
1066 case Bytecodes::_dstore_3: store_local_double(3); break;
1067
1068 case Bytecodes::_dup:
1069 {
1070 push(type_at_tos());
1071 break;
1072 }
1073 case Bytecodes::_dup_x1:
1074 {
1075 ciType* value1 = pop_value();
1076 ciType* value2 = pop_value();
1077 push(value1);
1078 push(value2);
1079 push(value1);
1080 break;
1081 }
1082 case Bytecodes::_dup_x2:
1083 {
1084 ciType* value1 = pop_value();
1085 ciType* value2 = pop_value();
1086 ciType* value3 = pop_value();
1087 push(value1);
1088 push(value3);
1089 push(value2);
1090 push(value1);
1091 break;
1092 }
1093 case Bytecodes::_dup2:
1094 {
1095 ciType* value1 = pop_value();
1096 ciType* value2 = pop_value();
1097 push(value2);
1098 push(value1);
1099 push(value2);
1100 push(value1);
1101 break;
1102 }
1103 case Bytecodes::_dup2_x1:
1104 {
1105 ciType* value1 = pop_value();
1106 ciType* value2 = pop_value();
1107 ciType* value3 = pop_value();
1108 push(value2);
1109 push(value1);
1110 push(value3);
1111 push(value2);
1112 push(value1);
1113 break;
1114 }
1115 case Bytecodes::_dup2_x2:
1116 {
1117 ciType* value1 = pop_value();
1118 ciType* value2 = pop_value();
1119 ciType* value3 = pop_value();
1120 ciType* value4 = pop_value();
1121 push(value2);
1122 push(value1);
1123 push(value4);
1124 push(value3);
1125 push(value2);
1126 push(value1);
1127 break;
1128 }
1129 case Bytecodes::_f2d:
1130 {
1131 pop_float();
1132 push_double();
1133 break;
1134 }
1135 case Bytecodes::_f2i:
1136 {
1137 pop_float();
1138 push_int();
1139 break;
1140 }
1141 case Bytecodes::_f2l:
1142 {
1143 pop_float();
1144 push_long();
1145 break;
1146 }
1147 case Bytecodes::_fadd:
1148 case Bytecodes::_fdiv:
1149 case Bytecodes::_fmul:
1150 case Bytecodes::_frem:
1151 case Bytecodes::_fsub:
1152 {
1153 pop_float();
1154 pop_float();
1155 push_float();
1156 break;
1157 }
1158 case Bytecodes::_faload:
1159 {
1160 pop_int();
1161 ciTypeArrayKlass* array_klass = pop_typeArray();
1162 // Put assert here.
1163 push_float();
1164 break;
1165 }
1166 case Bytecodes::_fastore:
1167 {
1168 pop_float();
1169 pop_int();
1170 ciTypeArrayKlass* array_klass = pop_typeArray();
1171 // Put assert here.
1172 break;
1173 }
1174 case Bytecodes::_fcmpg:
1175 case Bytecodes::_fcmpl:
1176 {
1177 pop_float();
1178 pop_float();
1179 push_int();
1180 break;
1181 }
1182 case Bytecodes::_fconst_0:
1183 case Bytecodes::_fconst_1:
1184 case Bytecodes::_fconst_2:
1185 {
1186 push_float();
1187 break;
1188 }
1189 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1190 case Bytecodes::_fload_0: load_local_float(0); break;
1191 case Bytecodes::_fload_1: load_local_float(1); break;
1192 case Bytecodes::_fload_2: load_local_float(2); break;
1193 case Bytecodes::_fload_3: load_local_float(3); break;
1194
1195 case Bytecodes::_fneg:
1196 {
1197 pop_float();
1198 push_float();
1199 break;
1200 }
1201 case Bytecodes::_freturn:
1202 {
1203 pop_float();
1204 break;
1205 }
1206 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1207 case Bytecodes::_fstore_0: store_local_float(0); break;
1208 case Bytecodes::_fstore_1: store_local_float(1); break;
1209 case Bytecodes::_fstore_2: store_local_float(2); break;
1210 case Bytecodes::_fstore_3: store_local_float(3); break;
1211
1212 case Bytecodes::_getfield: do_getfield(str); break;
1213 case Bytecodes::_getstatic: do_getstatic(str); break;
1214
1215 case Bytecodes::_goto:
1216 case Bytecodes::_goto_w:
1217 case Bytecodes::_nop:
1218 case Bytecodes::_return:
1219 {
1220 // do nothing.
1221 break;
1222 }
1223 case Bytecodes::_i2b:
1224 case Bytecodes::_i2c:
1225 case Bytecodes::_i2s:
1226 case Bytecodes::_ineg:
1227 {
1228 pop_int();
1229 push_int();
1230 break;
1231 }
1232 case Bytecodes::_i2d:
1233 {
1234 pop_int();
1235 push_double();
1236 break;
1237 }
1238 case Bytecodes::_i2f:
1239 {
1240 pop_int();
1241 push_float();
1242 break;
1243 }
1244 case Bytecodes::_i2l:
1245 {
1246 pop_int();
1247 push_long();
1248 break;
1249 }
1250 case Bytecodes::_iadd:
1251 case Bytecodes::_iand:
1252 case Bytecodes::_idiv:
1253 case Bytecodes::_imul:
1254 case Bytecodes::_ior:
1255 case Bytecodes::_irem:
1256 case Bytecodes::_ishl:
1257 case Bytecodes::_ishr:
1258 case Bytecodes::_isub:
1259 case Bytecodes::_iushr:
1260 case Bytecodes::_ixor:
1261 {
1262 pop_int();
1263 pop_int();
1264 push_int();
1265 break;
1266 }
1267 case Bytecodes::_if_acmpeq:
1268 case Bytecodes::_if_acmpne:
1269 {
1270 pop_object();
1271 pop_object();
1272 break;
1273 }
1274 case Bytecodes::_if_icmpeq:
1275 case Bytecodes::_if_icmpge:
1276 case Bytecodes::_if_icmpgt:
1277 case Bytecodes::_if_icmple:
1278 case Bytecodes::_if_icmplt:
1279 case Bytecodes::_if_icmpne:
1280 {
1281 pop_int();
1282 pop_int();
1283 break;
1284 }
1285 case Bytecodes::_ifeq:
1286 case Bytecodes::_ifle:
1287 case Bytecodes::_iflt:
1288 case Bytecodes::_ifge:
1289 case Bytecodes::_ifgt:
1290 case Bytecodes::_ifne:
1291 case Bytecodes::_ireturn:
1292 case Bytecodes::_lookupswitch:
1293 case Bytecodes::_tableswitch:
1294 {
1295 pop_int();
1296 break;
1297 }
1298 case Bytecodes::_iinc:
1299 {
1300 int lnum = str->get_index();
1301 check_int(local(lnum));
1302 store_to_local(lnum);
1303 break;
1304 }
1305 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1306 case Bytecodes::_iload_0: load_local_int(0); break;
1307 case Bytecodes::_iload_1: load_local_int(1); break;
1308 case Bytecodes::_iload_2: load_local_int(2); break;
1309 case Bytecodes::_iload_3: load_local_int(3); break;
1310
1311 case Bytecodes::_instanceof:
1312 {
1313 // Check for uncommon trap:
1314 do_checkcast(str);
1315 pop_object();
1316 push_int();
1317 break;
1318 }
1319 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1320 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1321 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1322
1323 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1324
1325 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1326 case Bytecodes::_istore_0: store_local_int(0); break;
1327 case Bytecodes::_istore_1: store_local_int(1); break;
1328 case Bytecodes::_istore_2: store_local_int(2); break;
1329 case Bytecodes::_istore_3: store_local_int(3); break;
1330
1331 case Bytecodes::_jsr:
1332 case Bytecodes::_jsr_w: do_jsr(str); break;
1333
1334 case Bytecodes::_l2d:
1335 {
1336 pop_long();
1337 push_double();
1338 break;
1339 }
1340 case Bytecodes::_l2f:
1341 {
1342 pop_long();
1343 push_float();
1344 break;
1345 }
1346 case Bytecodes::_l2i:
1347 {
1348 pop_long();
1349 push_int();
1350 break;
1351 }
1352 case Bytecodes::_ladd:
1353 case Bytecodes::_land:
1354 case Bytecodes::_ldiv:
1355 case Bytecodes::_lmul:
1356 case Bytecodes::_lor:
1357 case Bytecodes::_lrem:
1358 case Bytecodes::_lsub:
1359 case Bytecodes::_lxor:
1360 {
1361 pop_long();
1362 pop_long();
1363 push_long();
1364 break;
1365 }
1366 case Bytecodes::_laload:
1367 {
1368 pop_int();
1369 ciTypeArrayKlass* array_klass = pop_typeArray();
1370 // Put assert here for right type?
1371 push_long();
1372 break;
1373 }
1374 case Bytecodes::_lastore:
1375 {
1376 pop_long();
1377 pop_int();
1378 pop_typeArray();
1379 // assert here?
1380 break;
1381 }
1382 case Bytecodes::_lcmp:
1383 {
1384 pop_long();
1385 pop_long();
1386 push_int();
1387 break;
1388 }
1389 case Bytecodes::_lconst_0:
1390 case Bytecodes::_lconst_1:
1391 {
1392 push_long();
1393 break;
1394 }
1395 case Bytecodes::_ldc:
1396 case Bytecodes::_ldc_w:
1397 case Bytecodes::_ldc2_w:
1398 {
1399 do_ldc(str);
1400 break;
1401 }
1402
1403 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1404 case Bytecodes::_lload_0: load_local_long(0); break;
1405 case Bytecodes::_lload_1: load_local_long(1); break;
1406 case Bytecodes::_lload_2: load_local_long(2); break;
1407 case Bytecodes::_lload_3: load_local_long(3); break;
1408
1409 case Bytecodes::_lneg:
1410 {
1411 pop_long();
1412 push_long();
1413 break;
1414 }
1415 case Bytecodes::_lreturn:
1416 {
1417 pop_long();
1418 break;
1419 }
1420 case Bytecodes::_lshl:
1421 case Bytecodes::_lshr:
1422 case Bytecodes::_lushr:
1423 {
1424 pop_int();
1425 pop_long();
1426 push_long();
1427 break;
1428 }
1429 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1430 case Bytecodes::_lstore_0: store_local_long(0); break;
1431 case Bytecodes::_lstore_1: store_local_long(1); break;
1432 case Bytecodes::_lstore_2: store_local_long(2); break;
1433 case Bytecodes::_lstore_3: store_local_long(3); break;
1434
1435 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1436
1437 case Bytecodes::_new: do_new(str); break;
1438
1439 case Bytecodes::_newarray: do_newarray(str); break;
1440
1441 case Bytecodes::_pop:
1442 {
1443 pop();
1444 break;
1445 }
1446 case Bytecodes::_pop2:
1447 {
1448 pop();
1449 pop();
1450 break;
1451 }
1452
1453 case Bytecodes::_putfield: do_putfield(str); break;
1454 case Bytecodes::_putstatic: do_putstatic(str); break;
1455
1456 case Bytecodes::_ret: do_ret(str); break;
1457
1458 case Bytecodes::_swap:
1459 {
1460 ciType* value1 = pop_value();
1461 ciType* value2 = pop_value();
1462 push(value1);
1463 push(value2);
1464 break;
1465 }
1466 case Bytecodes::_wide:
1467 default:
1468 {
1469 // The iterator should skip this.
1470 ShouldNotReachHere();
1471 break;
1472 }
1473 }
1474
1475 if (CITraceTypeFlow) {
1476 print_on(tty);
1477 }
1478
1479 return (_trap_bci != -1);
1480 }
1481
1482 #ifndef PRODUCT
1483 // ------------------------------------------------------------------
1484 // ciTypeFlow::StateVector::print_cell_on
1485 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1486 ciType* type = type_at(c);
1487 if (type == top_type()) {
1488 st->print("top");
1489 } else if (type == bottom_type()) {
1490 st->print("bottom");
1491 } else if (type == null_type()) {
1492 st->print("null");
1493 } else if (type == long2_type()) {
1494 st->print("long2");
1495 } else if (type == double2_type()) {
1496 st->print("double2");
1497 } else if (is_int(type)) {
1498 st->print("int");
1499 } else if (is_long(type)) {
1500 st->print("long");
1501 } else if (is_float(type)) {
1502 st->print("float");
1503 } else if (is_double(type)) {
1504 st->print("double");
1505 } else if (type->is_return_address()) {
1506 st->print("address(%d)", type->as_return_address()->bci());
1507 } else {
1508 if (type->is_klass()) {
1509 type->as_klass()->name()->print_symbol_on(st);
1510 } else {
1511 st->print("UNEXPECTED TYPE");
1512 type->print();
1513 }
1514 }
1515 }
1516
1517 // ------------------------------------------------------------------
1518 // ciTypeFlow::StateVector::print_on
1519 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1520 int num_locals = _outer->max_locals();
1521 int num_stack = stack_size();
1522 int num_monitors = monitor_count();
1523 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1524 if (num_stack >= 0) {
1525 int i;
1526 for (i = 0; i < num_locals; i++) {
1527 st->print(" local %2d : ", i);
1528 print_cell_on(st, local(i));
1529 st->cr();
1530 }
1531 for (i = 0; i < num_stack; i++) {
1532 st->print(" stack %2d : ", i);
1533 print_cell_on(st, stack(i));
1534 st->cr();
1535 }
1536 }
1537 }
1538 #endif
1539
1540
1541 // ------------------------------------------------------------------
1542 // ciTypeFlow::SuccIter::next
1543 //
1544 void ciTypeFlow::SuccIter::next() {
1545 int succ_ct = _pred->successors()->length();
1546 int next = _index + 1;
1547 if (next < succ_ct) {
1548 _index = next;
1549 _succ = _pred->successors()->at(next);
1550 return;
1551 }
1552 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1553 // Do not compile any code for unloaded exception types.
1554 // Following compiler passes are responsible for doing this also.
1555 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1556 if (exception_klass->is_loaded()) {
1557 _index = next;
1558 _succ = _pred->exceptions()->at(i);
1559 return;
1560 }
1561 next++;
1562 }
1563 _index = -1;
1564 _succ = NULL;
1565 }
1566
1567 // ------------------------------------------------------------------
1568 // ciTypeFlow::SuccIter::set_succ
1569 //
1570 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1571 int succ_ct = _pred->successors()->length();
1572 if (_index < succ_ct) {
1573 _pred->successors()->at_put(_index, succ);
1574 } else {
1575 int idx = _index - succ_ct;
1576 _pred->exceptions()->at_put(idx, succ);
1577 }
1578 }
1579
1580 // ciTypeFlow::Block
1581 //
1582 // A basic block.
1583
1584 // ------------------------------------------------------------------
1585 // ciTypeFlow::Block::Block
1586 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1587 ciBlock *ciblk,
1588 ciTypeFlow::JsrSet* jsrs) {
1589 _ciblock = ciblk;
1590 _exceptions = NULL;
1591 _exc_klasses = NULL;
1592 _successors = NULL;
1593 _state = new (outer->arena()) StateVector(outer);
1594 JsrSet* new_jsrs =
1595 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1596 jsrs->copy_into(new_jsrs);
1597 _jsrs = new_jsrs;
1598 _next = NULL;
1599 _on_work_list = false;
1600 _backedge_copy = false;
1601 _exception_entry = false;
1602 _trap_bci = -1;
1603 _trap_index = 0;
1604 df_init();
1605
1606 if (CITraceTypeFlow) {
1607 tty->print_cr(">> Created new block");
1608 print_on(tty);
1609 }
1610
1611 assert(this->outer() == outer, "outer link set up");
1612 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1613 }
1614
1615
1616 bool ciTypeFlow::Block::delete_dead_addresses() {
1617 bool changed = false;
1618 if (_jsrs->size() != 0) {
1619 ciMethod* method = outer()->method();
1620 MethodLivenessResult live_locals = method->liveness_at_bci(start(), true);
1621 if (live_locals.is_valid()) {
1622 int addresses = 0;
1623 for (int i = 0; i < stack_size(); i++) {
1624 ciType* local = stack_type_at(i);
1625 if (local->is_return_address()) {
1626 addresses++;
1627 }
1628 }
1629 for (int i = 0; i < method->max_locals(); i++) {
1630 ciType* local = local_type_at(i);
1631 if (local->is_return_address()) {
1632 if (!live_locals.at(i)) {
1633 state()->set_type_at(state()->local(i), StateVector::bottom_type());
1634 changed = true;
1635 } else {
1636 addresses++;
1637 }
1638 }
1639 }
1640 if (addresses != _jsrs->size()) {
1641 // The size of the JsrSet and the number of address in the
1642 // state disagree so trim any unreachable JsrRecords.
1643 _jsrs->apply_state(state());
1644 }
1645 }
1646 }
1647 return changed;
1648 }
1649
1650 // ------------------------------------------------------------------
1651 // ciTypeFlow::Block::df_init
1652 void ciTypeFlow::Block::df_init() {
1653 _pre_order = -1; assert(!has_pre_order(), "");
1654 _post_order = -1; assert(!has_post_order(), "");
1655 _loop = NULL;
1656 _irreducible_entry = false;
1657 _rpo_next = NULL;
1658 }
1659
1660 // ------------------------------------------------------------------
1661 // ciTypeFlow::Block::successors
1662 //
1663 // Get the successors for this Block.
1664 GrowableArray<ciTypeFlow::Block*>*
1665 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1666 ciTypeFlow::StateVector* state,
1667 ciTypeFlow::JsrSet* jsrs) {
1668 if (_successors == NULL) {
1669 if (CITraceTypeFlow) {
1670 tty->print(">> Computing successors for block ");
1671 print_value_on(tty);
1672 tty->cr();
1673 }
1674
1675 ciTypeFlow* analyzer = outer();
1676 Arena* arena = analyzer->arena();
1677 Block* block = NULL;
1678 bool has_successor = !has_trap() &&
1679 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1680 if (!has_successor) {
1681 _successors =
1682 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1683 // No successors
1684 } else if (control() == ciBlock::fall_through_bci) {
1685 assert(str->cur_bci() == limit(), "bad block end");
1686 // This block simply falls through to the next.
1687 _successors =
1688 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1689
1690 Block* block = analyzer->block_at(limit(), _jsrs);
1691 assert(_successors->length() == FALL_THROUGH, "");
1692 _successors->append(block);
1693 } else {
1694 int current_bci = str->cur_bci();
1695 int next_bci = str->next_bci();
1696 int branch_bci = -1;
1697 Block* target = NULL;
1698 assert(str->next_bci() == limit(), "bad block end");
1699 // This block is not a simple fall-though. Interpret
1700 // the current bytecode to find our successors.
1701 switch (str->cur_bc()) {
1702 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1703 case Bytecodes::_iflt: case Bytecodes::_ifge:
1704 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1705 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1706 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1707 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1708 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1709 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1710 // Our successors are the branch target and the next bci.
1711 branch_bci = str->get_dest();
1712 _successors =
1713 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1714 assert(_successors->length() == IF_NOT_TAKEN, "");
1715 _successors->append(analyzer->block_at(next_bci, jsrs));
1716 assert(_successors->length() == IF_TAKEN, "");
1717 _successors->append(analyzer->block_at(branch_bci, jsrs));
1718 break;
1719
1720 case Bytecodes::_goto:
1721 branch_bci = str->get_dest();
1722 _successors =
1723 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1724 assert(_successors->length() == GOTO_TARGET, "");
1725 _successors->append(analyzer->block_at(branch_bci, jsrs));
1726 break;
1727
1728 case Bytecodes::_jsr:
1729 branch_bci = str->get_dest();
1730 _successors =
1731 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1732 assert(_successors->length() == GOTO_TARGET, "");
1733 _successors->append(analyzer->block_at(branch_bci, jsrs));
1734 break;
1735
1736 case Bytecodes::_goto_w:
1737 case Bytecodes::_jsr_w:
1738 _successors =
1739 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1740 assert(_successors->length() == GOTO_TARGET, "");
1741 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1742 break;
1743
1744 case Bytecodes::_tableswitch: {
1745 Bytecode_tableswitch *tableswitch =
1746 Bytecode_tableswitch_at(str->cur_bcp());
1747
1748 int len = tableswitch->length();
1749 _successors =
1750 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1751 int bci = current_bci + tableswitch->default_offset();
1752 Block* block = analyzer->block_at(bci, jsrs);
1753 assert(_successors->length() == SWITCH_DEFAULT, "");
1754 _successors->append(block);
1755 while (--len >= 0) {
1756 int bci = current_bci + tableswitch->dest_offset_at(len);
1757 block = analyzer->block_at(bci, jsrs);
1758 assert(_successors->length() >= SWITCH_CASES, "");
1759 _successors->append_if_missing(block);
1760 }
1761 break;
1762 }
1763
1764 case Bytecodes::_lookupswitch: {
1765 Bytecode_lookupswitch *lookupswitch =
1766 Bytecode_lookupswitch_at(str->cur_bcp());
1767
1768 int npairs = lookupswitch->number_of_pairs();
1769 _successors =
1770 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1771 int bci = current_bci + lookupswitch->default_offset();
1772 Block* block = analyzer->block_at(bci, jsrs);
1773 assert(_successors->length() == SWITCH_DEFAULT, "");
1774 _successors->append(block);
1775 while(--npairs >= 0) {
1776 LookupswitchPair *pair = lookupswitch->pair_at(npairs);
1777 int bci = current_bci + pair->offset();
1778 Block* block = analyzer->block_at(bci, jsrs);
1779 assert(_successors->length() >= SWITCH_CASES, "");
1780 _successors->append_if_missing(block);
1781 }
1782 break;
1783 }
1784
1785 case Bytecodes::_athrow: case Bytecodes::_ireturn:
1786 case Bytecodes::_lreturn: case Bytecodes::_freturn:
1787 case Bytecodes::_dreturn: case Bytecodes::_areturn:
1788 case Bytecodes::_return:
1789 _successors =
1790 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1791 // No successors
1792 break;
1793
1794 case Bytecodes::_ret: {
1795 _successors =
1796 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1797
1798 Cell local = state->local(str->get_index());
1799 ciType* return_address = state->type_at(local);
1800 assert(return_address->is_return_address(), "verify: wrong type");
1801 int bci = return_address->as_return_address()->bci();
1802 assert(_successors->length() == GOTO_TARGET, "");
1803 _successors->append(analyzer->block_at(bci, jsrs));
1804 break;
1805 }
1806
1807 case Bytecodes::_wide:
1808 default:
1809 ShouldNotReachHere();
1810 break;
1811 }
1812 }
1813 }
1814 return _successors;
1815 }
1816
1817 // ------------------------------------------------------------------
1818 // ciTypeFlow::Block:compute_exceptions
1819 //
1820 // Compute the exceptional successors and types for this Block.
1821 void ciTypeFlow::Block::compute_exceptions() {
1822 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1823
1824 if (CITraceTypeFlow) {
1825 tty->print(">> Computing exceptions for block ");
1826 print_value_on(tty);
1827 tty->cr();
1828 }
1829
1830 ciTypeFlow* analyzer = outer();
1831 Arena* arena = analyzer->arena();
1832
1833 // Any bci in the block will do.
1834 ciExceptionHandlerStream str(analyzer->method(), start());
1835
1836 // Allocate our growable arrays.
1837 int exc_count = str.count();
1838 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1839 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1840 0, NULL);
1841
1842 for ( ; !str.is_done(); str.next()) {
1843 ciExceptionHandler* handler = str.handler();
1844 int bci = handler->handler_bci();
1845 ciInstanceKlass* klass = NULL;
1846 if (bci == -1) {
1847 // There is no catch all. It is possible to exit the method.
1848 break;
1849 }
1850 if (handler->is_catch_all()) {
1851 klass = analyzer->env()->Throwable_klass();
1852 } else {
1853 klass = handler->catch_klass();
1854 }
1855 _exceptions->append(analyzer->block_at(bci, _jsrs));
1856 _exc_klasses->append(klass);
1857 }
1858 }
1859
1860 // ------------------------------------------------------------------
1861 // ciTypeFlow::Block::set_backedge_copy
1862 // Use this only to make a pre-existing public block into a backedge copy.
1863 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1864 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1865 _backedge_copy = z;
1866 }
1867
1868 // ------------------------------------------------------------------
1869 // ciTypeFlow::Block::is_clonable_exit
1870 //
1871 // At most 2 normal successors, one of which continues looping,
1872 // and all exceptional successors must exit.
1873 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1874 int normal_cnt = 0;
1875 int in_loop_cnt = 0;
1876 for (SuccIter iter(this); !iter.done(); iter.next()) {
1877 Block* succ = iter.succ();
1878 if (iter.is_normal_ctrl()) {
1879 if (++normal_cnt > 2) return false;
1880 if (lp->contains(succ->loop())) {
1881 if (++in_loop_cnt > 1) return false;
1882 }
1883 } else {
1884 if (lp->contains(succ->loop())) return false;
1885 }
1886 }
1887 return in_loop_cnt == 1;
1888 }
1889
1890 // ------------------------------------------------------------------
1891 // ciTypeFlow::Block::looping_succ
1892 //
1893 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1894 assert(successors()->length() <= 2, "at most 2 normal successors");
1895 for (SuccIter iter(this); !iter.done(); iter.next()) {
1896 Block* succ = iter.succ();
1897 if (lp->contains(succ->loop())) {
1898 return succ;
1899 }
1900 }
1901 return NULL;
1902 }
1903
1904 #ifndef PRODUCT
1905 // ------------------------------------------------------------------
1906 // ciTypeFlow::Block::print_value_on
1907 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1908 if (has_pre_order()) st->print("#%-2d ", pre_order());
1909 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1910 st->print("[%d - %d)", start(), limit());
1911 if (is_loop_head()) st->print(" lphd");
1912 if (is_irreducible_entry()) st->print(" irred");
1913 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1914 if (is_backedge_copy()) st->print("/backedge_copy");
1915 }
1916
1917 // ------------------------------------------------------------------
1918 // ciTypeFlow::Block::print_on
1919 void ciTypeFlow::Block::print_on(outputStream* st) const {
1920 if ((Verbose || WizardMode)) {
1921 outer()->method()->print_codes_on(start(), limit(), st);
1922 }
1923 st->print_cr(" ==================================================== ");
1924 st->print (" ");
1925 print_value_on(st);
1926 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1927 if (loop() && loop()->parent() != NULL) {
1928 st->print(" loops:");
1929 Loop* lp = loop();
1930 do {
1931 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1932 if (lp->is_irreducible()) st->print("(ir)");
1933 lp = lp->parent();
1934 } while (lp->parent() != NULL);
1935 }
1936 st->cr();
1937 _state->print_on(st);
1938 if (_successors == NULL) {
1939 st->print_cr(" No successor information");
1940 } else {
1941 int num_successors = _successors->length();
1942 st->print_cr(" Successors : %d", num_successors);
1943 for (int i = 0; i < num_successors; i++) {
1944 Block* successor = _successors->at(i);
1945 st->print(" ");
1946 successor->print_value_on(st);
1947 st->cr();
1948 }
1949 }
1950 if (_exceptions == NULL) {
1951 st->print_cr(" No exception information");
1952 } else {
1953 int num_exceptions = _exceptions->length();
1954 st->print_cr(" Exceptions : %d", num_exceptions);
1955 for (int i = 0; i < num_exceptions; i++) {
1956 Block* exc_succ = _exceptions->at(i);
1957 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
1958 st->print(" ");
1959 exc_succ->print_value_on(st);
1960 st->print(" -- ");
1961 exc_klass->name()->print_symbol_on(st);
1962 st->cr();
1963 }
1964 }
1965 if (has_trap()) {
1966 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
1967 }
1968 st->print_cr(" ==================================================== ");
1969 }
1970 #endif
1971
1972 #ifndef PRODUCT
1973 // ------------------------------------------------------------------
1974 // ciTypeFlow::LocalSet::print_on
1975 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
1976 st->print("{");
1977 for (int i = 0; i < max; i++) {
1978 if (test(i)) st->print(" %d", i);
1979 }
1980 if (limit > max) {
1981 st->print(" %d..%d ", max, limit);
1982 }
1983 st->print(" }");
1984 }
1985 #endif
1986
1987 // ciTypeFlow
1988 //
1989 // This is a pass over the bytecodes which computes the following:
1990 // basic block structure
1991 // interpreter type-states (a la the verifier)
1992
1993 // ------------------------------------------------------------------
1994 // ciTypeFlow::ciTypeFlow
1995 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
1996 _env = env;
1997 _method = method;
1998 _methodBlocks = method->get_method_blocks();
1999 _max_locals = method->max_locals();
2000 _max_stack = method->max_stack();
2001 _code_size = method->code_size();
2002 _has_irreducible_entry = false;
2003 _osr_bci = osr_bci;
2004 _failure_reason = NULL;
2005 assert(start_bci() >= 0 && start_bci() < code_size() , "correct osr_bci argument");
2006 _work_list = NULL;
2007
2008 _ciblock_count = _methodBlocks->num_blocks();
2009 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
2010 for (int i = 0; i < _ciblock_count; i++) {
2011 _idx_to_blocklist[i] = NULL;
2012 }
2013 _block_map = NULL; // until all blocks are seen
2014 _jsr_count = 0;
2015 _jsr_records = NULL;
2016 }
2017
2018 // ------------------------------------------------------------------
2019 // ciTypeFlow::work_list_next
2020 //
2021 // Get the next basic block from our work list.
2022 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2023 assert(!work_list_empty(), "work list must not be empty");
2024 Block* next_block = _work_list;
2025 _work_list = next_block->next();
2026 next_block->set_next(NULL);
2027 next_block->set_on_work_list(false);
2028 return next_block;
2029 }
2030
2031 // ------------------------------------------------------------------
2032 // ciTypeFlow::add_to_work_list
2033 //
2034 // Add a basic block to our work list.
2035 // List is sorted by decreasing postorder sort (same as increasing RPO)
2036 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2037 assert(!block->is_on_work_list(), "must not already be on work list");
2038
2039 if (CITraceTypeFlow) {
2040 tty->print(">> Adding block ");
2041 block->print_value_on(tty);
2042 tty->print_cr(" to the work list : ");
2043 }
2044
2045 block->set_on_work_list(true);
2046
2047 // decreasing post order sort
2048
2049 Block* prev = NULL;
2050 Block* current = _work_list;
2051 int po = block->post_order();
2052 while (current != NULL) {
2053 if (!current->has_post_order() || po > current->post_order())
2054 break;
2055 prev = current;
2056 current = current->next();
2057 }
2058 if (prev == NULL) {
2059 block->set_next(_work_list);
2060 _work_list = block;
2061 } else {
2062 block->set_next(current);
2063 prev->set_next(block);
2064 }
2065
2066 if (CITraceTypeFlow) {
2067 tty->cr();
2068 }
2069 }
2070
2071 // ------------------------------------------------------------------
2072 // ciTypeFlow::block_at
2073 //
2074 // Return the block beginning at bci which has a JsrSet compatible
2075 // with jsrs.
2076 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2077 // First find the right ciBlock.
2078 if (CITraceTypeFlow) {
2079 tty->print(">> Requesting block for %d/", bci);
2080 jsrs->print_on(tty);
2081 tty->cr();
2082 }
2083
2084 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2085 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2086 Block* block = get_block_for(ciblk->index(), jsrs, option);
2087
2088 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2089
2090 if (CITraceTypeFlow) {
2091 if (block != NULL) {
2092 tty->print(">> Found block ");
2093 block->print_value_on(tty);
2094 tty->cr();
2095 } else {
2096 tty->print_cr(">> No such block.");
2097 }
2098 }
2099
2100 return block;
2101 }
2102
2103 // ------------------------------------------------------------------
2104 // ciTypeFlow::make_jsr_record
2105 //
2106 // Make a JsrRecord for a given (entry, return) pair, if such a record
2107 // does not already exist.
2108 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2109 int return_address) {
2110 if (_jsr_records == NULL) {
2111 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2112 _jsr_count,
2113 0,
2114 NULL);
2115 }
2116 JsrRecord* record = NULL;
2117 int len = _jsr_records->length();
2118 for (int i = 0; i < len; i++) {
2119 JsrRecord* record = _jsr_records->at(i);
2120 if (record->entry_address() == entry_address &&
2121 record->return_address() == return_address) {
2122 return record;
2123 }
2124 }
2125
2126 record = new (arena()) JsrRecord(entry_address, return_address);
2127 _jsr_records->append(record);
2128 return record;
2129 }
2130
2131 // ------------------------------------------------------------------
2132 // ciTypeFlow::flow_exceptions
2133 //
2134 // Merge the current state into all exceptional successors at the
2135 // current point in the code.
2136 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2137 GrowableArray<ciInstanceKlass*>* exc_klasses,
2138 ciTypeFlow::StateVector* state) {
2139 int len = exceptions->length();
2140 assert(exc_klasses->length() == len, "must have same length");
2141 for (int i = 0; i < len; i++) {
2142 Block* block = exceptions->at(i);
2143 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2144
2145 if (!exception_klass->is_loaded()) {
2146 // Do not compile any code for unloaded exception types.
2147 // Following compiler passes are responsible for doing this also.
2148 continue;
2149 }
2150
2151 if (block->meet_exception(exception_klass, state)) {
2152 // Block was modified and has PO. Add it to the work list.
2153 if (block->has_post_order() &&
2154 !block->is_on_work_list()) {
2155 add_to_work_list(block);
2156 }
2157 }
2158 }
2159 }
2160
2161 // ------------------------------------------------------------------
2162 // ciTypeFlow::flow_successors
2163 //
2164 // Merge the current state into all successors at the current point
2165 // in the code.
2166 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2167 ciTypeFlow::StateVector* state) {
2168 int len = successors->length();
2169 for (int i = 0; i < len; i++) {
2170 Block* block = successors->at(i);
2171 if (block->meet(state)) {
2172 // Block was modified and has PO. Add it to the work list.
2173 if (block->has_post_order() &&
2174 !block->is_on_work_list()) {
2175 add_to_work_list(block);
2176 }
2177 }
2178 }
2179 }
2180
2181 // ------------------------------------------------------------------
2182 // ciTypeFlow::can_trap
2183 //
2184 // Tells if a given instruction is able to generate an exception edge.
2185 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2186 // Cf. GenerateOopMap::do_exception_edge.
2187 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2188
2189 switch (str.cur_bc()) {
2190 case Bytecodes::_ldc:
2191 case Bytecodes::_ldc_w:
2192 case Bytecodes::_ldc2_w:
2193 case Bytecodes::_aload_0:
2194 // These bytecodes can trap for rewriting. We need to assume that
2195 // they do not throw exceptions to make the monitor analysis work.
2196 return false;
2197
2198 case Bytecodes::_ireturn:
2199 case Bytecodes::_lreturn:
2200 case Bytecodes::_freturn:
2201 case Bytecodes::_dreturn:
2202 case Bytecodes::_areturn:
2203 case Bytecodes::_return:
2204 // We can assume the monitor stack is empty in this analysis.
2205 return false;
2206
2207 case Bytecodes::_monitorexit:
2208 // We can assume monitors are matched in this analysis.
2209 return false;
2210 }
2211
2212 return true;
2213 }
2214
2215 // ------------------------------------------------------------------
2216 // ciTypeFlow::clone_loop_heads
2217 //
2218 // Clone the loop heads
2219 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2220 bool rslt = false;
2221 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2222 lp = iter.current();
2223 Block* head = lp->head();
2224 if (lp == loop_tree_root() ||
2225 lp->is_irreducible() ||
2226 !head->is_clonable_exit(lp))
2227 continue;
2228
2229 // check not already cloned
2230 if (head->backedge_copy_count() != 0)
2231 continue;
2232
2233 // check _no_ shared head below us
2234 Loop* ch;
2235 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2236 if (ch != NULL)
2237 continue;
2238
2239 // Clone head
2240 Block* new_head = head->looping_succ(lp);
2241 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2242 // Update lp's info
2243 clone->set_loop(lp);
2244 lp->set_head(new_head);
2245 lp->set_tail(clone);
2246 // And move original head into outer loop
2247 head->set_loop(lp->parent());
2248
2249 rslt = true;
2250 }
2251 return rslt;
2252 }
2253
2254 // ------------------------------------------------------------------
2255 // ciTypeFlow::clone_loop_head
2256 //
2257 // Clone lp's head and replace tail's successors with clone.
2258 //
2259 // |
2260 // v
2261 // head <-> body
2262 // |
2263 // v
2264 // exit
2265 //
2266 // new_head
2267 //
2268 // |
2269 // v
2270 // head ----------\
2271 // | |
2272 // | v
2273 // | clone <-> body
2274 // | |
2275 // | /--/
2276 // | |
2277 // v v
2278 // exit
2279 //
2280 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2281 Block* head = lp->head();
2282 Block* tail = lp->tail();
2283 if (CITraceTypeFlow) {
2284 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2285 tty->print(" for predecessor "); tail->print_value_on(tty);
2286 tty->cr();
2287 }
2288 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2289 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2290
2291 assert(!clone->has_pre_order(), "just created");
2292 clone->set_next_pre_order();
2293
2294 // Insert clone after (orig) tail in reverse post order
2295 clone->set_rpo_next(tail->rpo_next());
2296 tail->set_rpo_next(clone);
2297
2298 // tail->head becomes tail->clone
2299 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2300 if (iter.succ() == head) {
2301 iter.set_succ(clone);
2302 }
2303 }
2304 flow_block(tail, temp_vector, temp_set);
2305 if (head == tail) {
2306 // For self-loops, clone->head becomes clone->clone
2307 flow_block(clone, temp_vector, temp_set);
2308 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2309 if (iter.succ() == head) {
2310 iter.set_succ(clone);
2311 break;
2312 }
2313 }
2314 }
2315 flow_block(clone, temp_vector, temp_set);
2316
2317 return clone;
2318 }
2319
2320 // ------------------------------------------------------------------
2321 // ciTypeFlow::flow_block
2322 //
2323 // Interpret the effects of the bytecodes on the incoming state
2324 // vector of a basic block. Push the changed state to succeeding
2325 // basic blocks.
2326 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2327 ciTypeFlow::StateVector* state,
2328 ciTypeFlow::JsrSet* jsrs) {
2329 if (CITraceTypeFlow) {
2330 tty->print("\n>> ANALYZING BLOCK : ");
2331 tty->cr();
2332 block->print_on(tty);
2333 }
2334 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2335
2336 if (UseNewCode3 && block->delete_dead_addresses()) {
2337 // Trimming addresses changed some locals to bottom so reflow the block
2338 if (block->has_post_order() &&
2339 !block->is_on_work_list()) {
2340 add_to_work_list(block);
2341 }
2342 }
2343
2344 int start = block->start();
2345 int limit = block->limit();
2346 int control = block->control();
2347 if (control != ciBlock::fall_through_bci) {
2348 limit = control;
2349 }
2350
2351 // Grab the state from the current block.
2352 block->copy_state_into(state);
2353 state->def_locals()->clear();
2354
2355 GrowableArray<Block*>* exceptions = block->exceptions();
2356 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2357 bool has_exceptions = exceptions->length() > 0;
2358
2359 bool exceptions_used = false;
2360
2361 ciBytecodeStream str(method());
2362 str.reset_to_bci(start);
2363 Bytecodes::Code code;
2364 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2365 str.cur_bci() < limit) {
2366 // Check for exceptional control flow from this point.
2367 if (has_exceptions && can_trap(str)) {
2368 flow_exceptions(exceptions, exc_klasses, state);
2369 exceptions_used = true;
2370 }
2371 // Apply the effects of the current bytecode to our state.
2372 bool res = state->apply_one_bytecode(&str);
2373
2374 // Watch for bailouts.
2375 if (failing()) return;
2376
2377 if (res) {
2378
2379 // We have encountered a trap. Record it in this block.
2380 block->set_trap(state->trap_bci(), state->trap_index());
2381
2382 if (CITraceTypeFlow) {
2383 tty->print_cr(">> Found trap");
2384 block->print_on(tty);
2385 }
2386
2387 // Save set of locals defined in this block
2388 block->def_locals()->add(state->def_locals());
2389
2390 // Record (no) successors.
2391 block->successors(&str, state, jsrs);
2392
2393 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2394
2395 // Discontinue interpretation of this Block.
2396 return;
2397 }
2398 }
2399
2400 GrowableArray<Block*>* successors = NULL;
2401 if (control != ciBlock::fall_through_bci) {
2402 // Check for exceptional control flow from this point.
2403 if (has_exceptions && can_trap(str)) {
2404 flow_exceptions(exceptions, exc_klasses, state);
2405 exceptions_used = true;
2406 }
2407
2408 // Fix the JsrSet to reflect effect of the bytecode.
2409 block->copy_jsrs_into(jsrs);
2410 jsrs->apply_control(this, &str, state);
2411
2412 // Find successor edges based on old state and new JsrSet.
2413 successors = block->successors(&str, state, jsrs);
2414
2415 // Apply the control changes to the state.
2416 state->apply_one_bytecode(&str);
2417 } else {
2418 // Fall through control
2419 successors = block->successors(&str, NULL, NULL);
2420 }
2421
2422 // Save set of locals defined in this block
2423 block->def_locals()->add(state->def_locals());
2424
2425 // Remove untaken exception paths
2426 if (!exceptions_used)
2427 exceptions->clear();
2428
2429 // Pass our state to successors.
2430 flow_successors(successors, state);
2431 }
2432
2433 // ------------------------------------------------------------------
2434 // ciTypeFlow::PostOrderLoops::next
2435 //
2436 // Advance to next loop tree using a postorder, left-to-right traversal.
2437 void ciTypeFlow::PostorderLoops::next() {
2438 assert(!done(), "must not be done.");
2439 if (_current->sibling() != NULL) {
2440 _current = _current->sibling();
2441 while (_current->child() != NULL) {
2442 _current = _current->child();
2443 }
2444 } else {
2445 _current = _current->parent();
2446 }
2447 }
2448
2449 // ------------------------------------------------------------------
2450 // ciTypeFlow::PreOrderLoops::next
2451 //
2452 // Advance to next loop tree using a preorder, left-to-right traversal.
2453 void ciTypeFlow::PreorderLoops::next() {
2454 assert(!done(), "must not be done.");
2455 if (_current->child() != NULL) {
2456 _current = _current->child();
2457 } else if (_current->sibling() != NULL) {
2458 _current = _current->sibling();
2459 } else {
2460 while (_current != _root && _current->sibling() == NULL) {
2461 _current = _current->parent();
2462 }
2463 if (_current == _root) {
2464 _current = NULL;
2465 assert(done(), "must be done.");
2466 } else {
2467 assert(_current->sibling() != NULL, "must be more to do");
2468 _current = _current->sibling();
2469 }
2470 }
2471 }
2472
2473 // ------------------------------------------------------------------
2474 // ciTypeFlow::Loop::sorted_merge
2475 //
2476 // Merge the branch lp into this branch, sorting on the loop head
2477 // pre_orders. Returns the leaf of the merged branch.
2478 // Child and sibling pointers will be setup later.
2479 // Sort is (looking from leaf towards the root)
2480 // descending on primary key: loop head's pre_order, and
2481 // ascending on secondary key: loop tail's pre_order.
2482 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2483 Loop* leaf = this;
2484 Loop* prev = NULL;
2485 Loop* current = leaf;
2486 while (lp != NULL) {
2487 int lp_pre_order = lp->head()->pre_order();
2488 // Find insertion point for "lp"
2489 while (current != NULL) {
2490 if (current == lp)
2491 return leaf; // Already in list
2492 if (current->head()->pre_order() < lp_pre_order)
2493 break;
2494 if (current->head()->pre_order() == lp_pre_order &&
2495 current->tail()->pre_order() > lp->tail()->pre_order()) {
2496 break;
2497 }
2498 prev = current;
2499 current = current->parent();
2500 }
2501 Loop* next_lp = lp->parent(); // Save future list of items to insert
2502 // Insert lp before current
2503 lp->set_parent(current);
2504 if (prev != NULL) {
2505 prev->set_parent(lp);
2506 } else {
2507 leaf = lp;
2508 }
2509 prev = lp; // Inserted item is new prev[ious]
2510 lp = next_lp; // Next item to insert
2511 }
2512 return leaf;
2513 }
2514
2515 // ------------------------------------------------------------------
2516 // ciTypeFlow::build_loop_tree
2517 //
2518 // Incrementally build loop tree.
2519 void ciTypeFlow::build_loop_tree(Block* blk) {
2520 assert(!blk->is_post_visited(), "precondition");
2521 Loop* innermost = NULL; // merge of loop tree branches over all successors
2522
2523 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2524 Loop* lp = NULL;
2525 Block* succ = iter.succ();
2526 if (!succ->is_post_visited()) {
2527 // Found backedge since predecessor post visited, but successor is not
2528 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2529
2530 // Create a LoopNode to mark this loop.
2531 lp = new (arena()) Loop(succ, blk);
2532 if (succ->loop() == NULL)
2533 succ->set_loop(lp);
2534 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2535
2536 } else { // Nested loop
2537 lp = succ->loop();
2538
2539 // If succ is loop head, find outer loop.
2540 while (lp != NULL && lp->head() == succ) {
2541 lp = lp->parent();
2542 }
2543 if (lp == NULL) {
2544 // Infinite loop, it's parent is the root
2545 lp = loop_tree_root();
2546 }
2547 }
2548
2549 // Check for irreducible loop.
2550 // Successor has already been visited. If the successor's loop head
2551 // has already been post-visited, then this is another entry into the loop.
2552 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2553 _has_irreducible_entry = true;
2554 lp->set_irreducible(succ);
2555 if (!succ->is_on_work_list()) {
2556 // Assume irreducible entries need more data flow
2557 add_to_work_list(succ);
2558 }
2559 lp = lp->parent();
2560 assert(lp != NULL, "nested loop must have parent by now");
2561 }
2562
2563 // Merge loop tree branch for all successors.
2564 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2565
2566 } // end loop
2567
2568 if (innermost == NULL) {
2569 assert(blk->successors()->length() == 0, "CFG exit");
2570 blk->set_loop(loop_tree_root());
2571 } else if (innermost->head() == blk) {
2572 // If loop header, complete the tree pointers
2573 if (blk->loop() != innermost) {
2574 #if ASSERT
2575 assert(blk->loop()->head() == innermost->head(), "same head");
2576 Loop* dl;
2577 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2578 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2579 #endif
2580 blk->set_loop(innermost);
2581 }
2582 innermost->def_locals()->add(blk->def_locals());
2583 Loop* l = innermost;
2584 Loop* p = l->parent();
2585 while (p && l->head() == blk) {
2586 l->set_sibling(p->child()); // Put self on parents 'next child'
2587 p->set_child(l); // Make self the first child of parent
2588 p->def_locals()->add(l->def_locals());
2589 l = p; // Walk up the parent chain
2590 p = l->parent();
2591 }
2592 } else {
2593 blk->set_loop(innermost);
2594 innermost->def_locals()->add(blk->def_locals());
2595 }
2596 }
2597
2598 // ------------------------------------------------------------------
2599 // ciTypeFlow::Loop::contains
2600 //
2601 // Returns true if lp is nested loop.
2602 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2603 assert(lp != NULL, "");
2604 if (this == lp || head() == lp->head()) return true;
2605 int depth1 = depth();
2606 int depth2 = lp->depth();
2607 if (depth1 > depth2)
2608 return false;
2609 while (depth1 < depth2) {
2610 depth2--;
2611 lp = lp->parent();
2612 }
2613 return this == lp;
2614 }
2615
2616 // ------------------------------------------------------------------
2617 // ciTypeFlow::Loop::depth
2618 //
2619 // Loop depth
2620 int ciTypeFlow::Loop::depth() const {
2621 int dp = 0;
2622 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2623 dp++;
2624 return dp;
2625 }
2626
2627 #ifndef PRODUCT
2628 // ------------------------------------------------------------------
2629 // ciTypeFlow::Loop::print
2630 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2631 for (int i = 0; i < indent; i++) st->print(" ");
2632 st->print("%d<-%d %s",
2633 is_root() ? 0 : this->head()->pre_order(),
2634 is_root() ? 0 : this->tail()->pre_order(),
2635 is_irreducible()?" irr":"");
2636 st->print(" defs: ");
2637 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2638 st->cr();
2639 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2640 ch->print(st, indent+2);
2641 }
2642 #endif
2643
2644 // ------------------------------------------------------------------
2645 // ciTypeFlow::df_flow_types
2646 //
2647 // Perform the depth first type flow analysis. Helper for flow_types.
2648 void ciTypeFlow::df_flow_types(Block* start,
2649 bool do_flow,
2650 StateVector* temp_vector,
2651 JsrSet* temp_set) {
2652 int dft_len = 100;
2653 GrowableArray<Block*> stk(arena(), dft_len, 0, NULL);
2654
2655 ciBlock* dummy = _methodBlocks->make_dummy_block();
2656 JsrSet* root_set = new JsrSet(NULL, 0);
2657 Block* root_head = new (arena()) Block(this, dummy, root_set);
2658 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2659 root_head->set_pre_order(0);
2660 root_head->set_post_order(0);
2661 root_tail->set_pre_order(max_jint);
2662 root_tail->set_post_order(max_jint);
2663 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2664
2665 stk.push(start);
2666
2667 _next_pre_order = 0; // initialize pre_order counter
2668 _rpo_list = NULL;
2669 int next_po = 0; // initialize post_order counter
2670
2671 // Compute RPO and the control flow graph
2672 int size;
2673 while ((size = stk.length()) > 0) {
2674 Block* blk = stk.top(); // Leave node on stack
2675 if (!blk->is_visited()) {
2676 // forward arc in graph
2677 assert (!blk->has_pre_order(), "");
2678 blk->set_next_pre_order();
2679
2680 if (_next_pre_order >= MaxNodeLimit / 2) {
2681 // Too many basic blocks. Bail out.
2682 // This can happen when try/finally constructs are nested to depth N,
2683 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2684 // "MaxNodeLimit / 2" is used because probably the parser will
2685 // generate at least twice that many nodes and bail out.
2686 record_failure("too many basic blocks");
2687 return;
2688 }
2689 if (do_flow) {
2690 flow_block(blk, temp_vector, temp_set);
2691 if (failing()) return; // Watch for bailouts.
2692 }
2693 } else if (!blk->is_post_visited()) {
2694 // cross or back arc
2695 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2696 Block* succ = iter.succ();
2697 if (!succ->is_visited()) {
2698 stk.push(succ);
2699 }
2700 }
2701 if (stk.length() == size) {
2702 // There were no additional children, post visit node now
2703 stk.pop(); // Remove node from stack
2704
2705 build_loop_tree(blk);
2706 blk->set_post_order(next_po++); // Assign post order
2707 prepend_to_rpo_list(blk);
2708 assert(blk->is_post_visited(), "");
2709
2710 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2711 // Assume loop heads need more data flow
2712 add_to_work_list(blk);
2713 }
2714 }
2715 } else {
2716 stk.pop(); // Remove post-visited node from stack
2717 }
2718 }
2719 }
2720
2721 // ------------------------------------------------------------------
2722 // ciTypeFlow::flow_types
2723 //
2724 // Perform the type flow analysis, creating and cloning Blocks as
2725 // necessary.
2726 void ciTypeFlow::flow_types() {
2727 ResourceMark rm;
2728 StateVector* temp_vector = new StateVector(this);
2729 JsrSet* temp_set = new JsrSet(NULL, 16);
2730
2731 // Create the method entry block.
2732 Block* start = block_at(start_bci(), temp_set);
2733
2734 // Load the initial state into it.
2735 const StateVector* start_state = get_start_state();
2736 if (failing()) return;
2737 start->meet(start_state);
2738
2739 // Depth first visit
2740 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2741
2742 if (failing()) return;
2743 assert(_rpo_list == start, "must be start");
2744
2745 // Any loops found?
2746 if (loop_tree_root()->child() != NULL &&
2747 env()->comp_level() >= CompLevel_full_optimization) {
2748 // Loop optimizations are not performed on Tier1 compiles.
2749
2750 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2751
2752 // If some loop heads were cloned, recompute postorder and loop tree
2753 if (changed) {
2754 loop_tree_root()->set_child(NULL);
2755 for (Block* blk = _rpo_list; blk != NULL;) {
2756 Block* next = blk->rpo_next();
2757 blk->df_init();
2758 blk = next;
2759 }
2760 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2761 }
2762 }
2763
2764 if (CITraceTypeFlow) {
2765 tty->print_cr("\nLoop tree");
2766 loop_tree_root()->print();
2767 }
2768
2769 // Continue flow analysis until fixed point reached
2770
2771 debug_only(int max_block = _next_pre_order;)
2772
2773 while (!work_list_empty()) {
2774 Block* blk = work_list_next();
2775 assert (blk->has_post_order(), "post order assigned above");
2776
2777 flow_block(blk, temp_vector, temp_set);
2778
2779 assert (max_block == _next_pre_order, "no new blocks");
2780 assert (!failing(), "no more bailouts");
2781 }
2782 }
2783
2784 // ------------------------------------------------------------------
2785 // ciTypeFlow::map_blocks
2786 //
2787 // Create the block map, which indexes blocks in reverse post-order.
2788 void ciTypeFlow::map_blocks() {
2789 assert(_block_map == NULL, "single initialization");
2790 int block_ct = _next_pre_order;
2791 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2792 assert(block_ct == block_count(), "");
2793
2794 Block* blk = _rpo_list;
2795 for (int m = 0; m < block_ct; m++) {
2796 int rpo = blk->rpo();
2797 assert(rpo == m, "should be sequential");
2798 _block_map[rpo] = blk;
2799 blk = blk->rpo_next();
2800 }
2801 assert(blk == NULL, "should be done");
2802
2803 for (int j = 0; j < block_ct; j++) {
2804 assert(_block_map[j] != NULL, "must not drop any blocks");
2805 Block* block = _block_map[j];
2806 // Remove dead blocks from successor lists:
2807 for (int e = 0; e <= 1; e++) {
2808 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2809 for (int k = 0; k < l->length(); k++) {
2810 Block* s = l->at(k);
2811 if (!s->has_post_order()) {
2812 if (CITraceTypeFlow) {
2813 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2814 s->print_value_on(tty);
2815 tty->cr();
2816 }
2817 l->remove(s);
2818 --k;
2819 }
2820 }
2821 }
2822 }
2823 }
2824
2825 // ------------------------------------------------------------------
2826 // ciTypeFlow::get_block_for
2827 //
2828 // Find a block with this ciBlock which has a compatible JsrSet.
2829 // If no such block exists, create it, unless the option is no_create.
2830 // If the option is create_backedge_copy, always create a fresh backedge copy.
2831 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2832 Arena* a = arena();
2833 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2834 if (blocks == NULL) {
2835 // Query only?
2836 if (option == no_create) return NULL;
2837
2838 // Allocate the growable array.
2839 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2840 _idx_to_blocklist[ciBlockIndex] = blocks;
2841 }
2842
2843 if (option != create_backedge_copy) {
2844 int len = blocks->length();
2845 for (int i = 0; i < len; i++) {
2846 Block* block = blocks->at(i);
2847 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2848 return block;
2849 }
2850 }
2851 }
2852
2853 // Query only?
2854 if (option == no_create) return NULL;
2855
2856 // We did not find a compatible block. Create one.
2857 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2858 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2859 blocks->append(new_block);
2860 return new_block;
2861 }
2862
2863 // ------------------------------------------------------------------
2864 // ciTypeFlow::backedge_copy_count
2865 //
2866 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2867 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2868
2869 if (blocks == NULL) {
2870 return 0;
2871 }
2872
2873 int count = 0;
2874 int len = blocks->length();
2875 for (int i = 0; i < len; i++) {
2876 Block* block = blocks->at(i);
2877 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2878 count++;
2879 }
2880 }
2881
2882 return count;
2883 }
2884
2885 // ------------------------------------------------------------------
2886 // ciTypeFlow::do_flow
2887 //
2888 // Perform type inference flow analysis.
2889 void ciTypeFlow::do_flow() {
2890 if (CITraceTypeFlow) {
2891 tty->print_cr("\nPerforming flow analysis on method");
2892 method()->print();
2893 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2894 tty->cr();
2895 method()->print_codes();
2896 }
2897 if (CITraceTypeFlow) {
2898 tty->print_cr("Initial CI Blocks");
2899 print_on(tty);
2900 }
2901 flow_types();
2902 // Watch for bailouts.
2903 if (failing()) {
2904 return;
2905 }
2906
2907 map_blocks();
2908
2909 if (UseNewCode) {
2910 tty->print_cr("*** ciTypeFlow blocks = %d", _next_pre_order);
2911 }
2912
2913 if (CIPrintTypeFlow || CITraceTypeFlow) {
2914 rpo_print_on(tty);
2915 }
2916 }
2917
2918 // ------------------------------------------------------------------
2919 // ciTypeFlow::record_failure()
2920 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
2921 // This is required because there is not a 1-1 relation between the ciEnv and
2922 // the TypeFlow passes within a compilation task. For example, if the compiler
2923 // is considering inlining a method, it will request a TypeFlow. If that fails,
2924 // the compilation as a whole may continue without the inlining. Some TypeFlow
2925 // requests are not optional; if they fail the requestor is responsible for
2926 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
2927 void ciTypeFlow::record_failure(const char* reason) {
2928 if (env()->log() != NULL) {
2929 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
2930 }
2931 if (_failure_reason == NULL) {
2932 // Record the first failure reason.
2933 _failure_reason = reason;
2934 }
2935 }
2936
2937 #ifndef PRODUCT
2938 // ------------------------------------------------------------------
2939 // ciTypeFlow::print_on
2940 void ciTypeFlow::print_on(outputStream* st) const {
2941 // Walk through CI blocks
2942 st->print_cr("********************************************************");
2943 st->print ("TypeFlow for ");
2944 method()->name()->print_symbol_on(st);
2945 int limit_bci = code_size();
2946 st->print_cr(" %d bytes", limit_bci);
2947 ciMethodBlocks *mblks = _methodBlocks;
2948 ciBlock* current = NULL;
2949 for (int bci = 0; bci < limit_bci; bci++) {
2950 ciBlock* blk = mblks->block_containing(bci);
2951 if (blk != NULL && blk != current) {
2952 current = blk;
2953 current->print_on(st);
2954
2955 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
2956 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
2957
2958 if (num_blocks == 0) {
2959 st->print_cr(" No Blocks");
2960 } else {
2961 for (int i = 0; i < num_blocks; i++) {
2962 Block* block = blocks->at(i);
2963 block->print_on(st);
2964 }
2965 }
2966 st->print_cr("--------------------------------------------------------");
2967 st->cr();
2968 }
2969 }
2970 st->print_cr("********************************************************");
2971 st->cr();
2972 }
2973
2974 void ciTypeFlow::rpo_print_on(outputStream* st) const {
2975 st->print_cr("********************************************************");
2976 st->print ("TypeFlow for ");
2977 method()->name()->print_symbol_on(st);
2978 int limit_bci = code_size();
2979 st->print_cr(" %d bytes", limit_bci);
2980 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
2981 blk->print_on(st);
2982 st->print_cr("--------------------------------------------------------");
2983 st->cr();
2984 }
2985 st->print_cr("********************************************************");
2986 st->cr();
2987 }
2988 #endif