1 /*
2 * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "ci/ciConstant.hpp"
27 #include "ci/ciField.hpp"
28 #include "ci/ciMethod.hpp"
29 #include "ci/ciMethodData.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciStreams.hpp"
32 #include "ci/ciTypeArrayKlass.hpp"
33 #include "ci/ciTypeFlow.hpp"
34 #include "ci/ciValueKlass.hpp"
35 #include "compiler/compileLog.hpp"
36 #include "interpreter/bytecode.hpp"
37 #include "interpreter/bytecodes.hpp"
38 #include "memory/allocation.inline.hpp"
39 #include "memory/resourceArea.hpp"
40 #include "oops/oop.inline.hpp"
41 #include "opto/compile.hpp"
42 #include "opto/node.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "utilities/growableArray.hpp"
45
46 // ciTypeFlow::JsrSet
47 //
48 // A JsrSet represents some set of JsrRecords. This class
49 // is used to record a set of all jsr routines which we permit
50 // execution to return (ret) from.
51 //
52 // During abstract interpretation, JsrSets are used to determine
53 // whether two paths which reach a given block are unique, and
54 // should be cloned apart, or are compatible, and should merge
55 // together.
56
57 // ------------------------------------------------------------------
58 // ciTypeFlow::JsrSet::JsrSet
59 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) {
60 if (arena != NULL) {
61 // Allocate growable array in Arena.
62 _set = new (arena) GrowableArray<JsrRecord*>(arena, default_len, 0, NULL);
63 } else {
64 // Allocate growable array in current ResourceArea.
65 _set = new GrowableArray<JsrRecord*>(4, 0, NULL, false);
66 }
67 }
68
69 // ------------------------------------------------------------------
70 // ciTypeFlow::JsrSet::copy_into
71 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) {
72 int len = size();
73 jsrs->_set->clear();
74 for (int i = 0; i < len; i++) {
75 jsrs->_set->append(_set->at(i));
76 }
77 }
78
79 // ------------------------------------------------------------------
80 // ciTypeFlow::JsrSet::is_compatible_with
81 //
82 // !!!! MISGIVINGS ABOUT THIS... disregard
83 //
84 // Is this JsrSet compatible with some other JsrSet?
85 //
86 // In set-theoretic terms, a JsrSet can be viewed as a partial function
87 // from entry addresses to return addresses. Two JsrSets A and B are
88 // compatible iff
89 //
90 // For any x,
91 // A(x) defined and B(x) defined implies A(x) == B(x)
92 //
93 // Less formally, two JsrSets are compatible when they have identical
94 // return addresses for any entry addresses they share in common.
95 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) {
96 // Walk through both sets in parallel. If the same entry address
97 // appears in both sets, then the return address must match for
98 // the sets to be compatible.
99 int size1 = size();
100 int size2 = other->size();
101
102 // Special case. If nothing is on the jsr stack, then there can
103 // be no ret.
104 if (size2 == 0) {
105 return true;
106 } else if (size1 != size2) {
107 return false;
108 } else {
109 for (int i = 0; i < size1; i++) {
110 JsrRecord* record1 = record_at(i);
111 JsrRecord* record2 = other->record_at(i);
112 if (record1->entry_address() != record2->entry_address() ||
113 record1->return_address() != record2->return_address()) {
114 return false;
115 }
116 }
117 return true;
118 }
119
120 #if 0
121 int pos1 = 0;
122 int pos2 = 0;
123 int size1 = size();
124 int size2 = other->size();
125 while (pos1 < size1 && pos2 < size2) {
126 JsrRecord* record1 = record_at(pos1);
127 JsrRecord* record2 = other->record_at(pos2);
128 int entry1 = record1->entry_address();
129 int entry2 = record2->entry_address();
130 if (entry1 < entry2) {
131 pos1++;
132 } else if (entry1 > entry2) {
133 pos2++;
134 } else {
135 if (record1->return_address() == record2->return_address()) {
136 pos1++;
137 pos2++;
138 } else {
139 // These two JsrSets are incompatible.
140 return false;
141 }
142 }
143 }
144 // The two JsrSets agree.
145 return true;
146 #endif
147 }
148
149 // ------------------------------------------------------------------
150 // ciTypeFlow::JsrSet::insert_jsr_record
151 //
152 // Insert the given JsrRecord into the JsrSet, maintaining the order
153 // of the set and replacing any element with the same entry address.
154 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) {
155 int len = size();
156 int entry = record->entry_address();
157 int pos = 0;
158 for ( ; pos < len; pos++) {
159 JsrRecord* current = record_at(pos);
160 if (entry == current->entry_address()) {
161 // Stomp over this entry.
162 _set->at_put(pos, record);
163 assert(size() == len, "must be same size");
164 return;
165 } else if (entry < current->entry_address()) {
166 break;
167 }
168 }
169
170 // Insert the record into the list.
171 JsrRecord* swap = record;
172 JsrRecord* temp = NULL;
173 for ( ; pos < len; pos++) {
174 temp = _set->at(pos);
175 _set->at_put(pos, swap);
176 swap = temp;
177 }
178 _set->append(swap);
179 assert(size() == len+1, "must be larger");
180 }
181
182 // ------------------------------------------------------------------
183 // ciTypeFlow::JsrSet::remove_jsr_record
184 //
185 // Remove the JsrRecord with the given return address from the JsrSet.
186 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) {
187 int len = size();
188 for (int i = 0; i < len; i++) {
189 if (record_at(i)->return_address() == return_address) {
190 // We have found the proper entry. Remove it from the
191 // JsrSet and exit.
192 for (int j = i+1; j < len ; j++) {
193 _set->at_put(j-1, _set->at(j));
194 }
195 _set->trunc_to(len-1);
196 assert(size() == len-1, "must be smaller");
197 return;
198 }
199 }
200 assert(false, "verify: returning from invalid subroutine");
201 }
202
203 // ------------------------------------------------------------------
204 // ciTypeFlow::JsrSet::apply_control
205 //
206 // Apply the effect of a control-flow bytecode on the JsrSet. The
207 // only bytecodes that modify the JsrSet are jsr and ret.
208 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer,
209 ciBytecodeStream* str,
210 ciTypeFlow::StateVector* state) {
211 Bytecodes::Code code = str->cur_bc();
212 if (code == Bytecodes::_jsr) {
213 JsrRecord* record =
214 analyzer->make_jsr_record(str->get_dest(), str->next_bci());
215 insert_jsr_record(record);
216 } else if (code == Bytecodes::_jsr_w) {
217 JsrRecord* record =
218 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci());
219 insert_jsr_record(record);
220 } else if (code == Bytecodes::_ret) {
221 Cell local = state->local(str->get_index());
222 ciType* return_address = state->type_at(local);
223 assert(return_address->is_return_address(), "verify: wrong type");
224 if (size() == 0) {
225 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out.
226 // This can happen when a loop is inside a finally clause (4614060).
227 analyzer->record_failure("OSR in finally clause");
228 return;
229 }
230 remove_jsr_record(return_address->as_return_address()->bci());
231 }
232 }
233
234 #ifndef PRODUCT
235 // ------------------------------------------------------------------
236 // ciTypeFlow::JsrSet::print_on
237 void ciTypeFlow::JsrSet::print_on(outputStream* st) const {
238 st->print("{ ");
239 int num_elements = size();
240 if (num_elements > 0) {
241 int i = 0;
242 for( ; i < num_elements - 1; i++) {
243 _set->at(i)->print_on(st);
244 st->print(", ");
245 }
246 _set->at(i)->print_on(st);
247 st->print(" ");
248 }
249 st->print("}");
250 }
251 #endif
252
253 // ciTypeFlow::StateVector
254 //
255 // A StateVector summarizes the type information at some point in
256 // the program.
257
258 // ------------------------------------------------------------------
259 // ciTypeFlow::StateVector::type_meet
260 //
261 // Meet two types.
262 //
263 // The semi-lattice of types use by this analysis are modeled on those
264 // of the verifier. The lattice is as follows:
265 //
266 // top_type() >= all non-extremal types >= bottom_type
267 // and
268 // Every primitive type is comparable only with itself. The meet of
269 // reference types is determined by their kind: instance class,
270 // interface, or array class. The meet of two types of the same
271 // kind is their least common ancestor. The meet of two types of
272 // different kinds is always java.lang.Object.
273 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) {
274 assert(t1 != t2, "checked in caller");
275
276 // Unwrap the types after gathering nullness information
277 bool never_null1 = t1->is_never_null();
278 bool never_null2 = t2->is_never_null();
279 t1 = t1->unwrap();
280 t2 = t2->unwrap();
281
282 if (t1->equals(top_type())) {
283 return t2;
284 } else if (t2->equals(top_type())) {
285 return t1;
286 } else if (t1->is_primitive_type() || t2->is_primitive_type()) {
287 // Special case null_type. null_type meet any reference type T
288 // is T. null_type meet null_type is null_type.
289 if (t1->equals(null_type())) {
290 if (!t2->is_primitive_type() || t2->equals(null_type())) {
291 return t2;
292 }
293 } else if (t2->equals(null_type())) {
294 if (!t1->is_primitive_type()) {
295 return t1;
296 }
297 }
298
299 // At least one of the two types is a non-top primitive type.
300 // The other type is not equal to it. Fall to bottom.
301 return bottom_type();
302 } else {
303 // Both types are non-top non-primitive types. That is,
304 // both types are either instanceKlasses or arrayKlasses.
305 ciKlass* object_klass = analyzer->env()->Object_klass();
306 ciKlass* k1 = t1->as_klass();
307 ciKlass* k2 = t2->as_klass();
308 if (k1->equals(object_klass) || k2->equals(object_klass)) {
309 return object_klass;
310 } else if (!k1->is_loaded() || !k2->is_loaded()) {
311 // Unloaded classes fall to java.lang.Object at a merge.
312 return object_klass;
313 } else if (k1->is_interface() != k2->is_interface()) {
314 // When an interface meets a non-interface, we get Object;
315 // This is what the verifier does.
316 return object_klass;
317 } else if (k1->is_array_klass() || k2->is_array_klass()) {
318 // When an array meets a non-array, we get Object.
319 // When objArray meets typeArray, we also get Object.
320 // And when typeArray meets different typeArray, we again get Object.
321 // But when objArray meets objArray, we look carefully at element types.
322 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) {
323 // Meet the element types, then construct the corresponding array type.
324 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass();
325 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass();
326 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
327 // Do an easy shortcut if one type is a super of the other.
328 if (elem == elem1) {
329 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK");
330 return k1;
331 } else if (elem == elem2) {
332 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK");
333 return k2;
334 } else {
335 return ciObjArrayKlass::make(elem);
336 }
337 } else if (k1->is_value_array_klass() || k2->is_value_array_klass()) {
338 ciKlass* elem1 = k1->as_array_klass()->element_klass();
339 ciKlass* elem2 = k2->as_array_klass()->element_klass();
340 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass();
341 return ciArrayKlass::make(elem);
342 } else {
343 return object_klass;
344 }
345 } else {
346 // Must be two plain old instance klasses.
347 assert(k1->is_instance_klass(), "previous cases handle non-instances");
348 assert(k2->is_instance_klass(), "previous cases handle non-instances");
349 ciType* result = k1->least_common_ancestor(k2);
350 if (never_null1 && never_null2 && result->is_valuetype()) {
351 // Both value types are never null, mark the result as never null
352 result = analyzer->mark_as_never_null(result);
353 }
354 return result;
355 }
356 }
357 }
358
359
360 // ------------------------------------------------------------------
361 // ciTypeFlow::StateVector::StateVector
362 //
363 // Build a new state vector
364 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) {
365 _outer = analyzer;
366 _stack_size = -1;
367 _monitor_count = -1;
368 // Allocate the _types array
369 int max_cells = analyzer->max_cells();
370 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells);
371 for (int i=0; i<max_cells; i++) {
372 _types[i] = top_type();
373 }
374 _trap_bci = -1;
375 _trap_index = 0;
376 _def_locals.clear();
377 }
378
379
380 // ------------------------------------------------------------------
381 // ciTypeFlow::get_start_state
382 //
383 // Set this vector to the method entry state.
384 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() {
385 StateVector* state = new StateVector(this);
386 if (is_osr_flow()) {
387 ciTypeFlow* non_osr_flow = method()->get_flow_analysis();
388 if (non_osr_flow->failing()) {
389 record_failure(non_osr_flow->failure_reason());
390 return NULL;
391 }
392 JsrSet* jsrs = new JsrSet(NULL, 16);
393 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs);
394 if (non_osr_block == NULL) {
395 record_failure("cannot reach OSR point");
396 return NULL;
397 }
398 // load up the non-OSR state at this point
399 non_osr_block->copy_state_into(state);
400 int non_osr_start = non_osr_block->start();
401 if (non_osr_start != start_bci()) {
402 // must flow forward from it
403 if (CITraceTypeFlow) {
404 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start);
405 }
406 Block* block = block_at(non_osr_start, jsrs);
407 assert(block->limit() == start_bci(), "must flow forward to start");
408 flow_block(block, state, jsrs);
409 }
410 return state;
411 // Note: The code below would be an incorrect for an OSR flow,
412 // even if it were possible for an OSR entry point to be at bci zero.
413 }
414 // "Push" the method signature into the first few locals.
415 state->set_stack_size(-max_locals());
416 if (!method()->is_static()) {
417 ciType* holder = method()->holder();
418 if (holder->is_valuetype()) {
419 // The receiver is never null
420 holder = mark_as_never_null(holder);
421 }
422 state->push(holder);
423 assert(state->tos() == state->local(0), "");
424 }
425 for (ciSignatureStream str(method()->signature());
426 !str.at_return_type();
427 str.next()) {
428 ciType* arg = str.type();
429 if (str.is_never_null()) {
430 arg = mark_as_never_null(arg);
431 }
432 state->push_translate(arg);
433 }
434 // Set the rest of the locals to bottom.
435 Cell cell = state->next_cell(state->tos());
436 state->set_stack_size(0);
437 int limit = state->limit_cell();
438 for (; cell < limit; cell = state->next_cell(cell)) {
439 state->set_type_at(cell, state->bottom_type());
440 }
441 // Lock an object, if necessary.
442 state->set_monitor_count(method()->is_synchronized() ? 1 : 0);
443 return state;
444 }
445
446 // ------------------------------------------------------------------
447 // ciTypeFlow::StateVector::copy_into
448 //
449 // Copy our value into some other StateVector
450 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy)
451 const {
452 copy->set_stack_size(stack_size());
453 copy->set_monitor_count(monitor_count());
454 Cell limit = limit_cell();
455 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
456 copy->set_type_at(c, type_at(c));
457 }
458 }
459
460 // ------------------------------------------------------------------
461 // ciTypeFlow::StateVector::meet
462 //
463 // Meets this StateVector with another, destructively modifying this
464 // one. Returns true if any modification takes place.
465 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) {
466 if (monitor_count() == -1) {
467 set_monitor_count(incoming->monitor_count());
468 }
469 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
470
471 if (stack_size() == -1) {
472 set_stack_size(incoming->stack_size());
473 Cell limit = limit_cell();
474 #ifdef ASSERT
475 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
476 assert(type_at(c) == top_type(), "");
477 } }
478 #endif
479 // Make a simple copy of the incoming state.
480 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
481 set_type_at(c, incoming->type_at(c));
482 }
483 return true; // it is always different the first time
484 }
485 #ifdef ASSERT
486 if (stack_size() != incoming->stack_size()) {
487 _outer->method()->print_codes();
488 tty->print_cr("!!!! Stack size conflict");
489 tty->print_cr("Current state:");
490 print_on(tty);
491 tty->print_cr("Incoming state:");
492 ((StateVector*)incoming)->print_on(tty);
493 }
494 #endif
495 assert(stack_size() == incoming->stack_size(), "sanity");
496
497 bool different = false;
498 Cell limit = limit_cell();
499 for (Cell c = start_cell(); c < limit; c = next_cell(c)) {
500 ciType* t1 = type_at(c);
501 ciType* t2 = incoming->type_at(c);
502 if (!t1->equals(t2)) {
503 ciType* new_type = type_meet(t1, t2);
504 if (!t1->equals(new_type)) {
505 set_type_at(c, new_type);
506 different = true;
507 }
508 }
509 }
510 return different;
511 }
512
513 // ------------------------------------------------------------------
514 // ciTypeFlow::StateVector::meet_exception
515 //
516 // Meets this StateVector with another, destructively modifying this
517 // one. The incoming state is coming via an exception. Returns true
518 // if any modification takes place.
519 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc,
520 const ciTypeFlow::StateVector* incoming) {
521 if (monitor_count() == -1) {
522 set_monitor_count(incoming->monitor_count());
523 }
524 assert(monitor_count() == incoming->monitor_count(), "monitors must match");
525
526 if (stack_size() == -1) {
527 set_stack_size(1);
528 }
529
530 assert(stack_size() == 1, "must have one-element stack");
531
532 bool different = false;
533
534 // Meet locals from incoming array.
535 Cell limit = local(_outer->max_locals()-1);
536 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) {
537 ciType* t1 = type_at(c);
538 ciType* t2 = incoming->type_at(c);
539 if (!t1->equals(t2)) {
540 ciType* new_type = type_meet(t1, t2);
541 if (!t1->equals(new_type)) {
542 set_type_at(c, new_type);
543 different = true;
544 }
545 }
546 }
547
548 // Handle stack separately. When an exception occurs, the
549 // only stack entry is the exception instance.
550 ciType* tos_type = type_at_tos();
551 if (!tos_type->equals(exc)) {
552 ciType* new_type = type_meet(tos_type, exc);
553 if (!tos_type->equals(new_type)) {
554 set_type_at_tos(new_type);
555 different = true;
556 }
557 }
558
559 return different;
560 }
561
562 // ------------------------------------------------------------------
563 // ciTypeFlow::StateVector::push_translate
564 void ciTypeFlow::StateVector::push_translate(ciType* type) {
565 BasicType basic_type = type->basic_type();
566 if (basic_type == T_BOOLEAN || basic_type == T_CHAR ||
567 basic_type == T_BYTE || basic_type == T_SHORT) {
568 push_int();
569 } else {
570 push(type);
571 if (type->is_two_word()) {
572 push(half_type(type));
573 }
574 }
575 }
576
577 // ------------------------------------------------------------------
578 // ciTypeFlow::StateVector::do_aload
579 void ciTypeFlow::StateVector::do_aload(ciBytecodeStream* str) {
580 pop_int();
581 ciArrayKlass* array_klass = pop_objOrValueArray();
582 if (array_klass == NULL) {
583 // Did aload on a null reference; push a null and ignore the exception.
584 // This instruction will never continue normally. All we have to do
585 // is report a value that will meet correctly with any downstream
586 // reference types on paths that will truly be executed. This null type
587 // meets with any reference type to yield that same reference type.
588 // (The compiler will generate an unconditional exception here.)
589 push(null_type());
590 return;
591 }
592 if (!array_klass->is_loaded()) {
593 // Only fails for some -Xcomp runs
594 trap(str, array_klass,
595 Deoptimization::make_trap_request
596 (Deoptimization::Reason_unloaded,
597 Deoptimization::Action_reinterpret));
598 return;
599 }
600 ciKlass* element_klass = array_klass->element_klass();
601 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) {
602 Untested("unloaded array element class in ciTypeFlow");
603 trap(str, element_klass,
604 Deoptimization::make_trap_request
605 (Deoptimization::Reason_unloaded,
606 Deoptimization::Action_reinterpret));
607 } else {
608 if (element_klass->is_valuetype()) {
609 // Value type array elements are never null
610 push(outer()->mark_as_never_null(element_klass));
611 } else {
612 push_object(element_klass);
613 }
614 }
615 }
616
617
618 // ------------------------------------------------------------------
619 // ciTypeFlow::StateVector::do_checkcast
620 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) {
621 bool will_link;
622 ciKlass* klass = str->get_klass(will_link);
623 if (!will_link) {
624 // VM's interpreter will not load 'klass' if object is NULL.
625 // Type flow after this block may still be needed in two situations:
626 // 1) C2 uses do_null_assert() and continues compilation for later blocks
627 // 2) C2 does an OSR compile in a later block (see bug 4778368).
628 pop_object();
629 do_null_assert(klass);
630 } else {
631 pop_object();
632 if (str->get_never_null()) {
633 assert(klass->is_valuetype(), "must be a value type");
634 push(outer()->mark_as_never_null(klass));
635 } else {
636 push_object(klass);
637 }
638 }
639 }
640
641 // ------------------------------------------------------------------
642 // ciTypeFlow::StateVector::do_getfield
643 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) {
644 // could add assert here for type of object.
645 pop_object();
646 do_getstatic(str);
647 }
648
649 // ------------------------------------------------------------------
650 // ciTypeFlow::StateVector::do_getstatic
651 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) {
652 bool will_link;
653 ciField* field = str->get_field(will_link);
654 if (!will_link) {
655 trap(str, field->holder(), str->get_field_holder_index());
656 } else {
657 ciType* field_type = field->type();
658 if (!field_type->is_loaded()) {
659 // Normally, we need the field's type to be loaded if we are to
660 // do anything interesting with its value.
661 // We used to do this: trap(str, str->get_field_signature_index());
662 //
663 // There is one good reason not to trap here. Execution can
664 // get past this "getfield" or "getstatic" if the value of
665 // the field is null. As long as the value is null, the class
666 // does not need to be loaded! The compiler must assume that
667 // the value of the unloaded class reference is null; if the code
668 // ever sees a non-null value, loading has occurred.
669 //
670 // This actually happens often enough to be annoying. If the
671 // compiler throws an uncommon trap at this bytecode, you can
672 // get an endless loop of recompilations, when all the code
673 // needs to do is load a series of null values. Also, a trap
674 // here can make an OSR entry point unreachable, triggering the
675 // assert on non_osr_block in ciTypeFlow::get_start_state.
676 // (See bug 4379915.)
677 do_null_assert(field_type->as_klass());
678 } else {
679 if (field->is_flattenable()) {
680 // A flattenable field is never null
681 field_type = outer()->mark_as_never_null(field_type);
682 }
683 push_translate(field_type);
684 }
685 }
686 }
687
688 // ------------------------------------------------------------------
689 // ciTypeFlow::StateVector::do_invoke
690 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str,
691 bool has_receiver) {
692 bool will_link;
693 ciSignature* declared_signature = NULL;
694 ciMethod* callee = str->get_method(will_link, &declared_signature);
695 assert(declared_signature != NULL, "cannot be null");
696 if (!will_link) {
697 // We weren't able to find the method.
698 if (str->cur_bc() == Bytecodes::_invokedynamic) {
699 trap(str, NULL,
700 Deoptimization::make_trap_request
701 (Deoptimization::Reason_uninitialized,
702 Deoptimization::Action_reinterpret));
703 } else {
704 ciKlass* unloaded_holder = callee->holder();
705 trap(str, unloaded_holder, str->get_method_holder_index());
706 }
707 } else {
708 // We are using the declared signature here because it might be
709 // different from the callee signature (Cf. invokedynamic and
710 // invokehandle).
711 ciSignatureStream sigstr(declared_signature);
712 const int arg_size = declared_signature->size();
713 const int stack_base = stack_size() - arg_size;
714 int i = 0;
715 for( ; !sigstr.at_return_type(); sigstr.next()) {
716 ciType* type = sigstr.type();
717 ciType* stack_type = type_at(stack(stack_base + i++));
718 // Do I want to check this type?
719 // assert(stack_type->is_subtype_of(type), "bad type for field value");
720 if (type->is_two_word()) {
721 ciType* stack_type2 = type_at(stack(stack_base + i++));
722 assert(stack_type2->equals(half_type(type)), "must be 2nd half");
723 }
724 }
725 assert(arg_size == i, "must match");
726 for (int j = 0; j < arg_size; j++) {
727 pop();
728 }
729 if (has_receiver) {
730 // Check this?
731 pop_object();
732 }
733 assert(!sigstr.is_done(), "must have return type");
734 ciType* return_type = sigstr.type();
735 if (!return_type->is_void()) {
736 if (!return_type->is_loaded()) {
737 // As in do_getstatic(), generally speaking, we need the return type to
738 // be loaded if we are to do anything interesting with its value.
739 // We used to do this: trap(str, str->get_method_signature_index());
740 //
741 // We do not trap here since execution can get past this invoke if
742 // the return value is null. As long as the value is null, the class
743 // does not need to be loaded! The compiler must assume that
744 // the value of the unloaded class reference is null; if the code
745 // ever sees a non-null value, loading has occurred.
746 //
747 // See do_getstatic() for similar explanation, as well as bug 4684993.
748 do_null_assert(return_type->as_klass());
749 } else {
750 if (sigstr.is_never_null()) {
751 return_type = outer()->mark_as_never_null(return_type);
752 }
753 push_translate(return_type);
754 }
755 }
756 }
757 }
758
759 // ------------------------------------------------------------------
760 // ciTypeFlow::StateVector::do_jsr
761 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) {
762 push(ciReturnAddress::make(str->next_bci()));
763 }
764
765 // ------------------------------------------------------------------
766 // ciTypeFlow::StateVector::do_ldc
767 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) {
768 ciConstant con = str->get_constant();
769 BasicType basic_type = con.basic_type();
770 if (basic_type == T_ILLEGAL) {
771 // OutOfMemoryError in the CI while loading constant
772 push_null();
773 outer()->record_failure("ldc did not link");
774 return;
775 }
776 if (basic_type == T_OBJECT || basic_type == T_OBJECT || basic_type == T_ARRAY) {
777 ciObject* obj = con.as_object();
778 if (obj->is_null_object()) {
779 push_null();
780 } else {
781 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass");
782 ciType* type = obj->klass();
783 if (type->is_valuetype()) {
784 type = outer()->mark_as_never_null(type);
785 }
786 push(type);
787 }
788 } else {
789 push_translate(ciType::make(basic_type));
790 }
791 }
792
793 // ------------------------------------------------------------------
794 // ciTypeFlow::StateVector::do_multianewarray
795 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) {
796 int dimensions = str->get_dimensions();
797 bool will_link;
798 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass();
799 if (!will_link) {
800 trap(str, array_klass, str->get_klass_index());
801 } else {
802 for (int i = 0; i < dimensions; i++) {
803 pop_int();
804 }
805 push_object(array_klass);
806 }
807 }
808
809 // ------------------------------------------------------------------
810 // ciTypeFlow::StateVector::do_new
811 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) {
812 bool will_link;
813 ciKlass* klass = str->get_klass(will_link);
814 if (!will_link || str->is_unresolved_klass()) {
815 trap(str, klass, str->get_klass_index());
816 } else {
817 push_object(klass);
818 }
819 }
820
821 // ------------------------------------------------------------------
822 // ciTypeFlow::StateVector::do_defaultvalue
823 void ciTypeFlow::StateVector::do_defaultvalue(ciBytecodeStream* str) {
824 bool will_link;
825 ciKlass* klass = str->get_klass(will_link);
826 if (!will_link) {
827 trap(str, klass, str->get_klass_index());
828 } else {
829 // The default value type is never null
830 push(outer()->mark_as_never_null(klass));
831 }
832 }
833
834 // ------------------------------------------------------------------
835 // ciTypeFlow::StateVector::do_withfield
836 void ciTypeFlow::StateVector::do_withfield(ciBytecodeStream* str) {
837 bool will_link;
838 ciField* field = str->get_field(will_link);
839 ciKlass* klass = field->holder();
840 if (!will_link) {
841 trap(str, klass, str->get_field_holder_index());
842 } else {
843 ciType* type = pop_value();
844 ciType* field_type = field->type();
845 assert(field_type->is_loaded(), "field type must be loaded");
846 if (field_type->is_two_word()) {
847 ciType* type2 = pop_value();
848 assert(type2->is_two_word(), "must be 2nd half");
849 assert(type == half_type(type2), "must be 2nd half");
850 }
851 pop_object();
852 // The newly created value type can never be null
853 push(outer()->mark_as_never_null(klass));
854 }
855 }
856
857 // ------------------------------------------------------------------
858 // ciTypeFlow::StateVector::do_newarray
859 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) {
860 pop_int();
861 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index());
862 push_object(klass);
863 }
864
865 // ------------------------------------------------------------------
866 // ciTypeFlow::StateVector::do_putfield
867 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) {
868 do_putstatic(str);
869 if (_trap_bci != -1) return; // unloaded field holder, etc.
870 // could add assert here for type of object.
871 pop_object();
872 }
873
874 // ------------------------------------------------------------------
875 // ciTypeFlow::StateVector::do_putstatic
876 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) {
877 bool will_link;
878 ciField* field = str->get_field(will_link);
879 if (!will_link) {
880 trap(str, field->holder(), str->get_field_holder_index());
881 } else {
882 ciType* field_type = field->type();
883 ciType* type = pop_value();
884 // Do I want to check this type?
885 // assert(type->is_subtype_of(field_type), "bad type for field value");
886 if (field_type->is_two_word()) {
887 ciType* type2 = pop_value();
888 assert(type2->is_two_word(), "must be 2nd half");
889 assert(type == half_type(type2), "must be 2nd half");
890 }
891 }
892 }
893
894 // ------------------------------------------------------------------
895 // ciTypeFlow::StateVector::do_ret
896 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) {
897 Cell index = local(str->get_index());
898
899 ciType* address = type_at(index);
900 assert(address->is_return_address(), "bad return address");
901 set_type_at(index, bottom_type());
902 }
903
904 // ------------------------------------------------------------------
905 // ciTypeFlow::StateVector::trap
906 //
907 // Stop interpretation of this path with a trap.
908 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) {
909 _trap_bci = str->cur_bci();
910 _trap_index = index;
911
912 // Log information about this trap:
913 CompileLog* log = outer()->env()->log();
914 if (log != NULL) {
915 int mid = log->identify(outer()->method());
916 int kid = (klass == NULL)? -1: log->identify(klass);
917 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci());
918 char buf[100];
919 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf),
920 index));
921 if (kid >= 0)
922 log->print(" klass='%d'", kid);
923 log->end_elem();
924 }
925 }
926
927 // ------------------------------------------------------------------
928 // ciTypeFlow::StateVector::do_null_assert
929 // Corresponds to graphKit::do_null_assert.
930 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) {
931 if (unloaded_klass->is_loaded()) {
932 // We failed to link, but we can still compute with this class,
933 // since it is loaded somewhere. The compiler will uncommon_trap
934 // if the object is not null, but the typeflow pass can not assume
935 // that the object will be null, otherwise it may incorrectly tell
936 // the parser that an object is known to be null. 4761344, 4807707
937 push_object(unloaded_klass);
938 } else {
939 // The class is not loaded anywhere. It is safe to model the
940 // null in the typestates, because we can compile in a null check
941 // which will deoptimize us if someone manages to load the
942 // class later.
943 push_null();
944 }
945 }
946
947
948 // ------------------------------------------------------------------
949 // ciTypeFlow::StateVector::apply_one_bytecode
950 //
951 // Apply the effect of one bytecode to this StateVector
952 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) {
953 _trap_bci = -1;
954 _trap_index = 0;
955
956 if (CITraceTypeFlow) {
957 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(),
958 Bytecodes::name(str->cur_bc()));
959 }
960
961 switch(str->cur_bc()) {
962 case Bytecodes::_aaload: do_aload(str); break;
963
964 case Bytecodes::_aastore:
965 {
966 pop_object();
967 pop_int();
968 pop_objOrValueArray();
969 break;
970 }
971 case Bytecodes::_aconst_null:
972 {
973 push_null();
974 break;
975 }
976 case Bytecodes::_aload: load_local_object(str->get_index()); break;
977 case Bytecodes::_aload_0: load_local_object(0); break;
978 case Bytecodes::_aload_1: load_local_object(1); break;
979 case Bytecodes::_aload_2: load_local_object(2); break;
980 case Bytecodes::_aload_3: load_local_object(3); break;
981
982 case Bytecodes::_anewarray:
983 {
984 pop_int();
985 bool will_link;
986 ciKlass* element_klass = str->get_klass(will_link);
987 if (!will_link) {
988 trap(str, element_klass, str->get_klass_index());
989 } else {
990 push_object(ciArrayKlass::make(element_klass));
991 }
992 break;
993 }
994 case Bytecodes::_areturn:
995 case Bytecodes::_ifnonnull:
996 case Bytecodes::_ifnull:
997 {
998 pop_object();
999 break;
1000 }
1001 case Bytecodes::_monitorenter:
1002 {
1003 pop_object();
1004 set_monitor_count(monitor_count() + 1);
1005 break;
1006 }
1007 case Bytecodes::_monitorexit:
1008 {
1009 pop_object();
1010 assert(monitor_count() > 0, "must be a monitor to exit from");
1011 set_monitor_count(monitor_count() - 1);
1012 break;
1013 }
1014 case Bytecodes::_arraylength:
1015 {
1016 pop_array();
1017 push_int();
1018 break;
1019 }
1020 case Bytecodes::_astore: store_local_object(str->get_index()); break;
1021 case Bytecodes::_astore_0: store_local_object(0); break;
1022 case Bytecodes::_astore_1: store_local_object(1); break;
1023 case Bytecodes::_astore_2: store_local_object(2); break;
1024 case Bytecodes::_astore_3: store_local_object(3); break;
1025
1026 case Bytecodes::_athrow:
1027 {
1028 NEEDS_CLEANUP;
1029 pop_object();
1030 break;
1031 }
1032 case Bytecodes::_baload:
1033 case Bytecodes::_caload:
1034 case Bytecodes::_iaload:
1035 case Bytecodes::_saload:
1036 {
1037 pop_int();
1038 ciTypeArrayKlass* array_klass = pop_typeArray();
1039 // Put assert here for right type?
1040 push_int();
1041 break;
1042 }
1043 case Bytecodes::_bastore:
1044 case Bytecodes::_castore:
1045 case Bytecodes::_iastore:
1046 case Bytecodes::_sastore:
1047 {
1048 pop_int();
1049 pop_int();
1050 pop_typeArray();
1051 // assert here?
1052 break;
1053 }
1054 case Bytecodes::_bipush:
1055 case Bytecodes::_iconst_m1:
1056 case Bytecodes::_iconst_0:
1057 case Bytecodes::_iconst_1:
1058 case Bytecodes::_iconst_2:
1059 case Bytecodes::_iconst_3:
1060 case Bytecodes::_iconst_4:
1061 case Bytecodes::_iconst_5:
1062 case Bytecodes::_sipush:
1063 {
1064 push_int();
1065 break;
1066 }
1067 case Bytecodes::_checkcast: do_checkcast(str); break;
1068
1069 case Bytecodes::_d2f:
1070 {
1071 pop_double();
1072 push_float();
1073 break;
1074 }
1075 case Bytecodes::_d2i:
1076 {
1077 pop_double();
1078 push_int();
1079 break;
1080 }
1081 case Bytecodes::_d2l:
1082 {
1083 pop_double();
1084 push_long();
1085 break;
1086 }
1087 case Bytecodes::_dadd:
1088 case Bytecodes::_ddiv:
1089 case Bytecodes::_dmul:
1090 case Bytecodes::_drem:
1091 case Bytecodes::_dsub:
1092 {
1093 pop_double();
1094 pop_double();
1095 push_double();
1096 break;
1097 }
1098 case Bytecodes::_daload:
1099 {
1100 pop_int();
1101 ciTypeArrayKlass* array_klass = pop_typeArray();
1102 // Put assert here for right type?
1103 push_double();
1104 break;
1105 }
1106 case Bytecodes::_dastore:
1107 {
1108 pop_double();
1109 pop_int();
1110 pop_typeArray();
1111 // assert here?
1112 break;
1113 }
1114 case Bytecodes::_dcmpg:
1115 case Bytecodes::_dcmpl:
1116 {
1117 pop_double();
1118 pop_double();
1119 push_int();
1120 break;
1121 }
1122 case Bytecodes::_dconst_0:
1123 case Bytecodes::_dconst_1:
1124 {
1125 push_double();
1126 break;
1127 }
1128 case Bytecodes::_dload: load_local_double(str->get_index()); break;
1129 case Bytecodes::_dload_0: load_local_double(0); break;
1130 case Bytecodes::_dload_1: load_local_double(1); break;
1131 case Bytecodes::_dload_2: load_local_double(2); break;
1132 case Bytecodes::_dload_3: load_local_double(3); break;
1133
1134 case Bytecodes::_dneg:
1135 {
1136 pop_double();
1137 push_double();
1138 break;
1139 }
1140 case Bytecodes::_dreturn:
1141 {
1142 pop_double();
1143 break;
1144 }
1145 case Bytecodes::_dstore: store_local_double(str->get_index()); break;
1146 case Bytecodes::_dstore_0: store_local_double(0); break;
1147 case Bytecodes::_dstore_1: store_local_double(1); break;
1148 case Bytecodes::_dstore_2: store_local_double(2); break;
1149 case Bytecodes::_dstore_3: store_local_double(3); break;
1150
1151 case Bytecodes::_dup:
1152 {
1153 push(type_at_tos());
1154 break;
1155 }
1156 case Bytecodes::_dup_x1:
1157 {
1158 ciType* value1 = pop_value();
1159 ciType* value2 = pop_value();
1160 push(value1);
1161 push(value2);
1162 push(value1);
1163 break;
1164 }
1165 case Bytecodes::_dup_x2:
1166 {
1167 ciType* value1 = pop_value();
1168 ciType* value2 = pop_value();
1169 ciType* value3 = pop_value();
1170 push(value1);
1171 push(value3);
1172 push(value2);
1173 push(value1);
1174 break;
1175 }
1176 case Bytecodes::_dup2:
1177 {
1178 ciType* value1 = pop_value();
1179 ciType* value2 = pop_value();
1180 push(value2);
1181 push(value1);
1182 push(value2);
1183 push(value1);
1184 break;
1185 }
1186 case Bytecodes::_dup2_x1:
1187 {
1188 ciType* value1 = pop_value();
1189 ciType* value2 = pop_value();
1190 ciType* value3 = pop_value();
1191 push(value2);
1192 push(value1);
1193 push(value3);
1194 push(value2);
1195 push(value1);
1196 break;
1197 }
1198 case Bytecodes::_dup2_x2:
1199 {
1200 ciType* value1 = pop_value();
1201 ciType* value2 = pop_value();
1202 ciType* value3 = pop_value();
1203 ciType* value4 = pop_value();
1204 push(value2);
1205 push(value1);
1206 push(value4);
1207 push(value3);
1208 push(value2);
1209 push(value1);
1210 break;
1211 }
1212 case Bytecodes::_f2d:
1213 {
1214 pop_float();
1215 push_double();
1216 break;
1217 }
1218 case Bytecodes::_f2i:
1219 {
1220 pop_float();
1221 push_int();
1222 break;
1223 }
1224 case Bytecodes::_f2l:
1225 {
1226 pop_float();
1227 push_long();
1228 break;
1229 }
1230 case Bytecodes::_fadd:
1231 case Bytecodes::_fdiv:
1232 case Bytecodes::_fmul:
1233 case Bytecodes::_frem:
1234 case Bytecodes::_fsub:
1235 {
1236 pop_float();
1237 pop_float();
1238 push_float();
1239 break;
1240 }
1241 case Bytecodes::_faload:
1242 {
1243 pop_int();
1244 ciTypeArrayKlass* array_klass = pop_typeArray();
1245 // Put assert here.
1246 push_float();
1247 break;
1248 }
1249 case Bytecodes::_fastore:
1250 {
1251 pop_float();
1252 pop_int();
1253 ciTypeArrayKlass* array_klass = pop_typeArray();
1254 // Put assert here.
1255 break;
1256 }
1257 case Bytecodes::_fcmpg:
1258 case Bytecodes::_fcmpl:
1259 {
1260 pop_float();
1261 pop_float();
1262 push_int();
1263 break;
1264 }
1265 case Bytecodes::_fconst_0:
1266 case Bytecodes::_fconst_1:
1267 case Bytecodes::_fconst_2:
1268 {
1269 push_float();
1270 break;
1271 }
1272 case Bytecodes::_fload: load_local_float(str->get_index()); break;
1273 case Bytecodes::_fload_0: load_local_float(0); break;
1274 case Bytecodes::_fload_1: load_local_float(1); break;
1275 case Bytecodes::_fload_2: load_local_float(2); break;
1276 case Bytecodes::_fload_3: load_local_float(3); break;
1277
1278 case Bytecodes::_fneg:
1279 {
1280 pop_float();
1281 push_float();
1282 break;
1283 }
1284 case Bytecodes::_freturn:
1285 {
1286 pop_float();
1287 break;
1288 }
1289 case Bytecodes::_fstore: store_local_float(str->get_index()); break;
1290 case Bytecodes::_fstore_0: store_local_float(0); break;
1291 case Bytecodes::_fstore_1: store_local_float(1); break;
1292 case Bytecodes::_fstore_2: store_local_float(2); break;
1293 case Bytecodes::_fstore_3: store_local_float(3); break;
1294
1295 case Bytecodes::_getfield: do_getfield(str); break;
1296 case Bytecodes::_getstatic: do_getstatic(str); break;
1297
1298 case Bytecodes::_goto:
1299 case Bytecodes::_goto_w:
1300 case Bytecodes::_nop:
1301 case Bytecodes::_return:
1302 {
1303 // do nothing.
1304 break;
1305 }
1306 case Bytecodes::_i2b:
1307 case Bytecodes::_i2c:
1308 case Bytecodes::_i2s:
1309 case Bytecodes::_ineg:
1310 {
1311 pop_int();
1312 push_int();
1313 break;
1314 }
1315 case Bytecodes::_i2d:
1316 {
1317 pop_int();
1318 push_double();
1319 break;
1320 }
1321 case Bytecodes::_i2f:
1322 {
1323 pop_int();
1324 push_float();
1325 break;
1326 }
1327 case Bytecodes::_i2l:
1328 {
1329 pop_int();
1330 push_long();
1331 break;
1332 }
1333 case Bytecodes::_iadd:
1334 case Bytecodes::_iand:
1335 case Bytecodes::_idiv:
1336 case Bytecodes::_imul:
1337 case Bytecodes::_ior:
1338 case Bytecodes::_irem:
1339 case Bytecodes::_ishl:
1340 case Bytecodes::_ishr:
1341 case Bytecodes::_isub:
1342 case Bytecodes::_iushr:
1343 case Bytecodes::_ixor:
1344 {
1345 pop_int();
1346 pop_int();
1347 push_int();
1348 break;
1349 }
1350 case Bytecodes::_if_acmpeq:
1351 case Bytecodes::_if_acmpne:
1352 {
1353 pop_object();
1354 pop_object();
1355 break;
1356 }
1357 case Bytecodes::_if_icmpeq:
1358 case Bytecodes::_if_icmpge:
1359 case Bytecodes::_if_icmpgt:
1360 case Bytecodes::_if_icmple:
1361 case Bytecodes::_if_icmplt:
1362 case Bytecodes::_if_icmpne:
1363 {
1364 pop_int();
1365 pop_int();
1366 break;
1367 }
1368 case Bytecodes::_ifeq:
1369 case Bytecodes::_ifle:
1370 case Bytecodes::_iflt:
1371 case Bytecodes::_ifge:
1372 case Bytecodes::_ifgt:
1373 case Bytecodes::_ifne:
1374 case Bytecodes::_ireturn:
1375 case Bytecodes::_lookupswitch:
1376 case Bytecodes::_tableswitch:
1377 {
1378 pop_int();
1379 break;
1380 }
1381 case Bytecodes::_iinc:
1382 {
1383 int lnum = str->get_index();
1384 check_int(local(lnum));
1385 store_to_local(lnum);
1386 break;
1387 }
1388 case Bytecodes::_iload: load_local_int(str->get_index()); break;
1389 case Bytecodes::_iload_0: load_local_int(0); break;
1390 case Bytecodes::_iload_1: load_local_int(1); break;
1391 case Bytecodes::_iload_2: load_local_int(2); break;
1392 case Bytecodes::_iload_3: load_local_int(3); break;
1393
1394 case Bytecodes::_instanceof:
1395 {
1396 // Check for uncommon trap:
1397 do_checkcast(str);
1398 pop_object();
1399 push_int();
1400 break;
1401 }
1402 case Bytecodes::_invokeinterface: do_invoke(str, true); break;
1403 case Bytecodes::_invokespecial: do_invoke(str, true); break;
1404 case Bytecodes::_invokestatic: do_invoke(str, false); break;
1405 case Bytecodes::_invokevirtual: do_invoke(str, true); break;
1406 case Bytecodes::_invokedynamic: do_invoke(str, false); break;
1407
1408 case Bytecodes::_istore: store_local_int(str->get_index()); break;
1409 case Bytecodes::_istore_0: store_local_int(0); break;
1410 case Bytecodes::_istore_1: store_local_int(1); break;
1411 case Bytecodes::_istore_2: store_local_int(2); break;
1412 case Bytecodes::_istore_3: store_local_int(3); break;
1413
1414 case Bytecodes::_jsr:
1415 case Bytecodes::_jsr_w: do_jsr(str); break;
1416
1417 case Bytecodes::_l2d:
1418 {
1419 pop_long();
1420 push_double();
1421 break;
1422 }
1423 case Bytecodes::_l2f:
1424 {
1425 pop_long();
1426 push_float();
1427 break;
1428 }
1429 case Bytecodes::_l2i:
1430 {
1431 pop_long();
1432 push_int();
1433 break;
1434 }
1435 case Bytecodes::_ladd:
1436 case Bytecodes::_land:
1437 case Bytecodes::_ldiv:
1438 case Bytecodes::_lmul:
1439 case Bytecodes::_lor:
1440 case Bytecodes::_lrem:
1441 case Bytecodes::_lsub:
1442 case Bytecodes::_lxor:
1443 {
1444 pop_long();
1445 pop_long();
1446 push_long();
1447 break;
1448 }
1449 case Bytecodes::_laload:
1450 {
1451 pop_int();
1452 ciTypeArrayKlass* array_klass = pop_typeArray();
1453 // Put assert here for right type?
1454 push_long();
1455 break;
1456 }
1457 case Bytecodes::_lastore:
1458 {
1459 pop_long();
1460 pop_int();
1461 pop_typeArray();
1462 // assert here?
1463 break;
1464 }
1465 case Bytecodes::_lcmp:
1466 {
1467 pop_long();
1468 pop_long();
1469 push_int();
1470 break;
1471 }
1472 case Bytecodes::_lconst_0:
1473 case Bytecodes::_lconst_1:
1474 {
1475 push_long();
1476 break;
1477 }
1478 case Bytecodes::_ldc:
1479 case Bytecodes::_ldc_w:
1480 case Bytecodes::_ldc2_w:
1481 {
1482 do_ldc(str);
1483 break;
1484 }
1485
1486 case Bytecodes::_lload: load_local_long(str->get_index()); break;
1487 case Bytecodes::_lload_0: load_local_long(0); break;
1488 case Bytecodes::_lload_1: load_local_long(1); break;
1489 case Bytecodes::_lload_2: load_local_long(2); break;
1490 case Bytecodes::_lload_3: load_local_long(3); break;
1491
1492 case Bytecodes::_lneg:
1493 {
1494 pop_long();
1495 push_long();
1496 break;
1497 }
1498 case Bytecodes::_lreturn:
1499 {
1500 pop_long();
1501 break;
1502 }
1503 case Bytecodes::_lshl:
1504 case Bytecodes::_lshr:
1505 case Bytecodes::_lushr:
1506 {
1507 pop_int();
1508 pop_long();
1509 push_long();
1510 break;
1511 }
1512 case Bytecodes::_lstore: store_local_long(str->get_index()); break;
1513 case Bytecodes::_lstore_0: store_local_long(0); break;
1514 case Bytecodes::_lstore_1: store_local_long(1); break;
1515 case Bytecodes::_lstore_2: store_local_long(2); break;
1516 case Bytecodes::_lstore_3: store_local_long(3); break;
1517
1518 case Bytecodes::_multianewarray: do_multianewarray(str); break;
1519
1520 case Bytecodes::_new: do_new(str); break;
1521
1522 case Bytecodes::_defaultvalue: do_defaultvalue(str); break;
1523 case Bytecodes::_withfield: do_withfield(str); break;
1524
1525 case Bytecodes::_newarray: do_newarray(str); break;
1526
1527 case Bytecodes::_pop:
1528 {
1529 pop();
1530 break;
1531 }
1532 case Bytecodes::_pop2:
1533 {
1534 pop();
1535 pop();
1536 break;
1537 }
1538
1539 case Bytecodes::_putfield: do_putfield(str); break;
1540 case Bytecodes::_putstatic: do_putstatic(str); break;
1541
1542 case Bytecodes::_ret: do_ret(str); break;
1543
1544 case Bytecodes::_swap:
1545 {
1546 ciType* value1 = pop_value();
1547 ciType* value2 = pop_value();
1548 push(value1);
1549 push(value2);
1550 break;
1551 }
1552
1553 case Bytecodes::_wide:
1554 default:
1555 {
1556 // The iterator should skip this.
1557 ShouldNotReachHere();
1558 break;
1559 }
1560 }
1561
1562 if (CITraceTypeFlow) {
1563 print_on(tty);
1564 }
1565
1566 return (_trap_bci != -1);
1567 }
1568
1569 #ifndef PRODUCT
1570 // ------------------------------------------------------------------
1571 // ciTypeFlow::StateVector::print_cell_on
1572 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const {
1573 ciType* type = type_at(c);
1574 if (type == top_type()) {
1575 st->print("top");
1576 } else if (type == bottom_type()) {
1577 st->print("bottom");
1578 } else if (type == null_type()) {
1579 st->print("null");
1580 } else if (type == long2_type()) {
1581 st->print("long2");
1582 } else if (type == double2_type()) {
1583 st->print("double2");
1584 } else if (is_int(type)) {
1585 st->print("int");
1586 } else if (is_long(type)) {
1587 st->print("long");
1588 } else if (is_float(type)) {
1589 st->print("float");
1590 } else if (is_double(type)) {
1591 st->print("double");
1592 } else if (type->is_return_address()) {
1593 st->print("address(%d)", type->as_return_address()->bci());
1594 } else {
1595 if (type->is_klass()) {
1596 type->as_klass()->name()->print_symbol_on(st);
1597 } else {
1598 st->print("UNEXPECTED TYPE");
1599 type->print();
1600 }
1601 }
1602 }
1603
1604 // ------------------------------------------------------------------
1605 // ciTypeFlow::StateVector::print_on
1606 void ciTypeFlow::StateVector::print_on(outputStream* st) const {
1607 int num_locals = _outer->max_locals();
1608 int num_stack = stack_size();
1609 int num_monitors = monitor_count();
1610 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors);
1611 if (num_stack >= 0) {
1612 int i;
1613 for (i = 0; i < num_locals; i++) {
1614 st->print(" local %2d : ", i);
1615 print_cell_on(st, local(i));
1616 st->cr();
1617 }
1618 for (i = 0; i < num_stack; i++) {
1619 st->print(" stack %2d : ", i);
1620 print_cell_on(st, stack(i));
1621 st->cr();
1622 }
1623 }
1624 }
1625 #endif
1626
1627
1628 // ------------------------------------------------------------------
1629 // ciTypeFlow::SuccIter::next
1630 //
1631 void ciTypeFlow::SuccIter::next() {
1632 int succ_ct = _pred->successors()->length();
1633 int next = _index + 1;
1634 if (next < succ_ct) {
1635 _index = next;
1636 _succ = _pred->successors()->at(next);
1637 return;
1638 }
1639 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) {
1640 // Do not compile any code for unloaded exception types.
1641 // Following compiler passes are responsible for doing this also.
1642 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i);
1643 if (exception_klass->is_loaded()) {
1644 _index = next;
1645 _succ = _pred->exceptions()->at(i);
1646 return;
1647 }
1648 next++;
1649 }
1650 _index = -1;
1651 _succ = NULL;
1652 }
1653
1654 // ------------------------------------------------------------------
1655 // ciTypeFlow::SuccIter::set_succ
1656 //
1657 void ciTypeFlow::SuccIter::set_succ(Block* succ) {
1658 int succ_ct = _pred->successors()->length();
1659 if (_index < succ_ct) {
1660 _pred->successors()->at_put(_index, succ);
1661 } else {
1662 int idx = _index - succ_ct;
1663 _pred->exceptions()->at_put(idx, succ);
1664 }
1665 }
1666
1667 // ciTypeFlow::Block
1668 //
1669 // A basic block.
1670
1671 // ------------------------------------------------------------------
1672 // ciTypeFlow::Block::Block
1673 ciTypeFlow::Block::Block(ciTypeFlow* outer,
1674 ciBlock *ciblk,
1675 ciTypeFlow::JsrSet* jsrs) {
1676 _ciblock = ciblk;
1677 _exceptions = NULL;
1678 _exc_klasses = NULL;
1679 _successors = NULL;
1680 _predecessors = new (outer->arena()) GrowableArray<Block*>(outer->arena(), 1, 0, NULL);
1681 _state = new (outer->arena()) StateVector(outer);
1682 JsrSet* new_jsrs =
1683 new (outer->arena()) JsrSet(outer->arena(), jsrs->size());
1684 jsrs->copy_into(new_jsrs);
1685 _jsrs = new_jsrs;
1686 _next = NULL;
1687 _on_work_list = false;
1688 _backedge_copy = false;
1689 _has_monitorenter = false;
1690 _trap_bci = -1;
1691 _trap_index = 0;
1692 df_init();
1693
1694 if (CITraceTypeFlow) {
1695 tty->print_cr(">> Created new block");
1696 print_on(tty);
1697 }
1698
1699 assert(this->outer() == outer, "outer link set up");
1700 assert(!outer->have_block_count(), "must not have mapped blocks yet");
1701 }
1702
1703 // ------------------------------------------------------------------
1704 // ciTypeFlow::Block::df_init
1705 void ciTypeFlow::Block::df_init() {
1706 _pre_order = -1; assert(!has_pre_order(), "");
1707 _post_order = -1; assert(!has_post_order(), "");
1708 _loop = NULL;
1709 _irreducible_entry = false;
1710 _rpo_next = NULL;
1711 }
1712
1713 // ------------------------------------------------------------------
1714 // ciTypeFlow::Block::successors
1715 //
1716 // Get the successors for this Block.
1717 GrowableArray<ciTypeFlow::Block*>*
1718 ciTypeFlow::Block::successors(ciBytecodeStream* str,
1719 ciTypeFlow::StateVector* state,
1720 ciTypeFlow::JsrSet* jsrs) {
1721 if (_successors == NULL) {
1722 if (CITraceTypeFlow) {
1723 tty->print(">> Computing successors for block ");
1724 print_value_on(tty);
1725 tty->cr();
1726 }
1727
1728 ciTypeFlow* analyzer = outer();
1729 Arena* arena = analyzer->arena();
1730 Block* block = NULL;
1731 bool has_successor = !has_trap() &&
1732 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size());
1733 if (!has_successor) {
1734 _successors =
1735 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1736 // No successors
1737 } else if (control() == ciBlock::fall_through_bci) {
1738 assert(str->cur_bci() == limit(), "bad block end");
1739 // This block simply falls through to the next.
1740 _successors =
1741 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1742
1743 Block* block = analyzer->block_at(limit(), _jsrs);
1744 assert(_successors->length() == FALL_THROUGH, "");
1745 _successors->append(block);
1746 } else {
1747 int current_bci = str->cur_bci();
1748 int next_bci = str->next_bci();
1749 int branch_bci = -1;
1750 Block* target = NULL;
1751 assert(str->next_bci() == limit(), "bad block end");
1752 // This block is not a simple fall-though. Interpret
1753 // the current bytecode to find our successors.
1754 switch (str->cur_bc()) {
1755 case Bytecodes::_ifeq: case Bytecodes::_ifne:
1756 case Bytecodes::_iflt: case Bytecodes::_ifge:
1757 case Bytecodes::_ifgt: case Bytecodes::_ifle:
1758 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne:
1759 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge:
1760 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple:
1761 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne:
1762 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull:
1763 // Our successors are the branch target and the next bci.
1764 branch_bci = str->get_dest();
1765 _successors =
1766 new (arena) GrowableArray<Block*>(arena, 2, 0, NULL);
1767 assert(_successors->length() == IF_NOT_TAKEN, "");
1768 _successors->append(analyzer->block_at(next_bci, jsrs));
1769 assert(_successors->length() == IF_TAKEN, "");
1770 _successors->append(analyzer->block_at(branch_bci, jsrs));
1771 break;
1772
1773 case Bytecodes::_goto:
1774 branch_bci = str->get_dest();
1775 _successors =
1776 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1777 assert(_successors->length() == GOTO_TARGET, "");
1778 _successors->append(analyzer->block_at(branch_bci, jsrs));
1779 break;
1780
1781 case Bytecodes::_jsr:
1782 branch_bci = str->get_dest();
1783 _successors =
1784 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1785 assert(_successors->length() == GOTO_TARGET, "");
1786 _successors->append(analyzer->block_at(branch_bci, jsrs));
1787 break;
1788
1789 case Bytecodes::_goto_w:
1790 case Bytecodes::_jsr_w:
1791 _successors =
1792 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1793 assert(_successors->length() == GOTO_TARGET, "");
1794 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs));
1795 break;
1796
1797 case Bytecodes::_tableswitch: {
1798 Bytecode_tableswitch tableswitch(str);
1799
1800 int len = tableswitch.length();
1801 _successors =
1802 new (arena) GrowableArray<Block*>(arena, len+1, 0, NULL);
1803 int bci = current_bci + tableswitch.default_offset();
1804 Block* block = analyzer->block_at(bci, jsrs);
1805 assert(_successors->length() == SWITCH_DEFAULT, "");
1806 _successors->append(block);
1807 while (--len >= 0) {
1808 int bci = current_bci + tableswitch.dest_offset_at(len);
1809 block = analyzer->block_at(bci, jsrs);
1810 assert(_successors->length() >= SWITCH_CASES, "");
1811 _successors->append_if_missing(block);
1812 }
1813 break;
1814 }
1815
1816 case Bytecodes::_lookupswitch: {
1817 Bytecode_lookupswitch lookupswitch(str);
1818
1819 int npairs = lookupswitch.number_of_pairs();
1820 _successors =
1821 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, NULL);
1822 int bci = current_bci + lookupswitch.default_offset();
1823 Block* block = analyzer->block_at(bci, jsrs);
1824 assert(_successors->length() == SWITCH_DEFAULT, "");
1825 _successors->append(block);
1826 while(--npairs >= 0) {
1827 LookupswitchPair pair = lookupswitch.pair_at(npairs);
1828 int bci = current_bci + pair.offset();
1829 Block* block = analyzer->block_at(bci, jsrs);
1830 assert(_successors->length() >= SWITCH_CASES, "");
1831 _successors->append_if_missing(block);
1832 }
1833 break;
1834 }
1835
1836 case Bytecodes::_athrow:
1837 case Bytecodes::_ireturn:
1838 case Bytecodes::_lreturn:
1839 case Bytecodes::_freturn:
1840 case Bytecodes::_dreturn:
1841 case Bytecodes::_areturn:
1842 case Bytecodes::_return:
1843 _successors =
1844 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1845 // No successors
1846 break;
1847
1848 case Bytecodes::_ret: {
1849 _successors =
1850 new (arena) GrowableArray<Block*>(arena, 1, 0, NULL);
1851
1852 Cell local = state->local(str->get_index());
1853 ciType* return_address = state->type_at(local);
1854 assert(return_address->is_return_address(), "verify: wrong type");
1855 int bci = return_address->as_return_address()->bci();
1856 assert(_successors->length() == GOTO_TARGET, "");
1857 _successors->append(analyzer->block_at(bci, jsrs));
1858 break;
1859 }
1860
1861 case Bytecodes::_wide:
1862 default:
1863 ShouldNotReachHere();
1864 break;
1865 }
1866 }
1867
1868 // Set predecessor information
1869 for (int i = 0; i < _successors->length(); i++) {
1870 Block* block = _successors->at(i);
1871 block->predecessors()->append(this);
1872 }
1873 }
1874 return _successors;
1875 }
1876
1877 // ------------------------------------------------------------------
1878 // ciTypeFlow::Block:compute_exceptions
1879 //
1880 // Compute the exceptional successors and types for this Block.
1881 void ciTypeFlow::Block::compute_exceptions() {
1882 assert(_exceptions == NULL && _exc_klasses == NULL, "repeat");
1883
1884 if (CITraceTypeFlow) {
1885 tty->print(">> Computing exceptions for block ");
1886 print_value_on(tty);
1887 tty->cr();
1888 }
1889
1890 ciTypeFlow* analyzer = outer();
1891 Arena* arena = analyzer->arena();
1892
1893 // Any bci in the block will do.
1894 ciExceptionHandlerStream str(analyzer->method(), start());
1895
1896 // Allocate our growable arrays.
1897 int exc_count = str.count();
1898 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, NULL);
1899 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count,
1900 0, NULL);
1901
1902 for ( ; !str.is_done(); str.next()) {
1903 ciExceptionHandler* handler = str.handler();
1904 int bci = handler->handler_bci();
1905 ciInstanceKlass* klass = NULL;
1906 if (bci == -1) {
1907 // There is no catch all. It is possible to exit the method.
1908 break;
1909 }
1910 if (handler->is_catch_all()) {
1911 klass = analyzer->env()->Throwable_klass();
1912 } else {
1913 klass = handler->catch_klass();
1914 }
1915 Block* block = analyzer->block_at(bci, _jsrs);
1916 _exceptions->append(block);
1917 block->predecessors()->append(this);
1918 _exc_klasses->append(klass);
1919 }
1920 }
1921
1922 // ------------------------------------------------------------------
1923 // ciTypeFlow::Block::set_backedge_copy
1924 // Use this only to make a pre-existing public block into a backedge copy.
1925 void ciTypeFlow::Block::set_backedge_copy(bool z) {
1926 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public");
1927 _backedge_copy = z;
1928 }
1929
1930 // ------------------------------------------------------------------
1931 // ciTypeFlow::Block::is_clonable_exit
1932 //
1933 // At most 2 normal successors, one of which continues looping,
1934 // and all exceptional successors must exit.
1935 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) {
1936 int normal_cnt = 0;
1937 int in_loop_cnt = 0;
1938 for (SuccIter iter(this); !iter.done(); iter.next()) {
1939 Block* succ = iter.succ();
1940 if (iter.is_normal_ctrl()) {
1941 if (++normal_cnt > 2) return false;
1942 if (lp->contains(succ->loop())) {
1943 if (++in_loop_cnt > 1) return false;
1944 }
1945 } else {
1946 if (lp->contains(succ->loop())) return false;
1947 }
1948 }
1949 return in_loop_cnt == 1;
1950 }
1951
1952 // ------------------------------------------------------------------
1953 // ciTypeFlow::Block::looping_succ
1954 //
1955 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) {
1956 assert(successors()->length() <= 2, "at most 2 normal successors");
1957 for (SuccIter iter(this); !iter.done(); iter.next()) {
1958 Block* succ = iter.succ();
1959 if (lp->contains(succ->loop())) {
1960 return succ;
1961 }
1962 }
1963 return NULL;
1964 }
1965
1966 #ifndef PRODUCT
1967 // ------------------------------------------------------------------
1968 // ciTypeFlow::Block::print_value_on
1969 void ciTypeFlow::Block::print_value_on(outputStream* st) const {
1970 if (has_pre_order()) st->print("#%-2d ", pre_order());
1971 if (has_rpo()) st->print("rpo#%-2d ", rpo());
1972 st->print("[%d - %d)", start(), limit());
1973 if (is_loop_head()) st->print(" lphd");
1974 if (is_irreducible_entry()) st->print(" irred");
1975 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); }
1976 if (is_backedge_copy()) st->print("/backedge_copy");
1977 }
1978
1979 // ------------------------------------------------------------------
1980 // ciTypeFlow::Block::print_on
1981 void ciTypeFlow::Block::print_on(outputStream* st) const {
1982 if ((Verbose || WizardMode) && (limit() >= 0)) {
1983 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1')
1984 outer()->method()->print_codes_on(start(), limit(), st);
1985 }
1986 st->print_cr(" ==================================================== ");
1987 st->print (" ");
1988 print_value_on(st);
1989 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr();
1990 if (loop() && loop()->parent() != NULL) {
1991 st->print(" loops:");
1992 Loop* lp = loop();
1993 do {
1994 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order());
1995 if (lp->is_irreducible()) st->print("(ir)");
1996 lp = lp->parent();
1997 } while (lp->parent() != NULL);
1998 }
1999 st->cr();
2000 _state->print_on(st);
2001 if (_successors == NULL) {
2002 st->print_cr(" No successor information");
2003 } else {
2004 int num_successors = _successors->length();
2005 st->print_cr(" Successors : %d", num_successors);
2006 for (int i = 0; i < num_successors; i++) {
2007 Block* successor = _successors->at(i);
2008 st->print(" ");
2009 successor->print_value_on(st);
2010 st->cr();
2011 }
2012 }
2013 if (_predecessors == NULL) {
2014 st->print_cr(" No predecessor information");
2015 } else {
2016 int num_predecessors = _predecessors->length();
2017 st->print_cr(" Predecessors : %d", num_predecessors);
2018 for (int i = 0; i < num_predecessors; i++) {
2019 Block* predecessor = _predecessors->at(i);
2020 st->print(" ");
2021 predecessor->print_value_on(st);
2022 st->cr();
2023 }
2024 }
2025 if (_exceptions == NULL) {
2026 st->print_cr(" No exception information");
2027 } else {
2028 int num_exceptions = _exceptions->length();
2029 st->print_cr(" Exceptions : %d", num_exceptions);
2030 for (int i = 0; i < num_exceptions; i++) {
2031 Block* exc_succ = _exceptions->at(i);
2032 ciInstanceKlass* exc_klass = _exc_klasses->at(i);
2033 st->print(" ");
2034 exc_succ->print_value_on(st);
2035 st->print(" -- ");
2036 exc_klass->name()->print_symbol_on(st);
2037 st->cr();
2038 }
2039 }
2040 if (has_trap()) {
2041 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index());
2042 }
2043 st->print_cr(" ==================================================== ");
2044 }
2045 #endif
2046
2047 #ifndef PRODUCT
2048 // ------------------------------------------------------------------
2049 // ciTypeFlow::LocalSet::print_on
2050 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const {
2051 st->print("{");
2052 for (int i = 0; i < max; i++) {
2053 if (test(i)) st->print(" %d", i);
2054 }
2055 if (limit > max) {
2056 st->print(" %d..%d ", max, limit);
2057 }
2058 st->print(" }");
2059 }
2060 #endif
2061
2062 // ciTypeFlow
2063 //
2064 // This is a pass over the bytecodes which computes the following:
2065 // basic block structure
2066 // interpreter type-states (a la the verifier)
2067
2068 // ------------------------------------------------------------------
2069 // ciTypeFlow::ciTypeFlow
2070 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) {
2071 _env = env;
2072 _method = method;
2073 _methodBlocks = method->get_method_blocks();
2074 _max_locals = method->max_locals();
2075 _max_stack = method->max_stack();
2076 _code_size = method->code_size();
2077 _has_irreducible_entry = false;
2078 _osr_bci = osr_bci;
2079 _failure_reason = NULL;
2080 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size());
2081 _work_list = NULL;
2082
2083 _ciblock_count = _methodBlocks->num_blocks();
2084 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, _ciblock_count);
2085 for (int i = 0; i < _ciblock_count; i++) {
2086 _idx_to_blocklist[i] = NULL;
2087 }
2088 _block_map = NULL; // until all blocks are seen
2089 _jsr_count = 0;
2090 _jsr_records = NULL;
2091 }
2092
2093 // ------------------------------------------------------------------
2094 // ciTypeFlow::work_list_next
2095 //
2096 // Get the next basic block from our work list.
2097 ciTypeFlow::Block* ciTypeFlow::work_list_next() {
2098 assert(!work_list_empty(), "work list must not be empty");
2099 Block* next_block = _work_list;
2100 _work_list = next_block->next();
2101 next_block->set_next(NULL);
2102 next_block->set_on_work_list(false);
2103 return next_block;
2104 }
2105
2106 // ------------------------------------------------------------------
2107 // ciTypeFlow::add_to_work_list
2108 //
2109 // Add a basic block to our work list.
2110 // List is sorted by decreasing postorder sort (same as increasing RPO)
2111 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) {
2112 assert(!block->is_on_work_list(), "must not already be on work list");
2113
2114 if (CITraceTypeFlow) {
2115 tty->print(">> Adding block ");
2116 block->print_value_on(tty);
2117 tty->print_cr(" to the work list : ");
2118 }
2119
2120 block->set_on_work_list(true);
2121
2122 // decreasing post order sort
2123
2124 Block* prev = NULL;
2125 Block* current = _work_list;
2126 int po = block->post_order();
2127 while (current != NULL) {
2128 if (!current->has_post_order() || po > current->post_order())
2129 break;
2130 prev = current;
2131 current = current->next();
2132 }
2133 if (prev == NULL) {
2134 block->set_next(_work_list);
2135 _work_list = block;
2136 } else {
2137 block->set_next(current);
2138 prev->set_next(block);
2139 }
2140
2141 if (CITraceTypeFlow) {
2142 tty->cr();
2143 }
2144 }
2145
2146 // ------------------------------------------------------------------
2147 // ciTypeFlow::block_at
2148 //
2149 // Return the block beginning at bci which has a JsrSet compatible
2150 // with jsrs.
2151 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2152 // First find the right ciBlock.
2153 if (CITraceTypeFlow) {
2154 tty->print(">> Requesting block for %d/", bci);
2155 jsrs->print_on(tty);
2156 tty->cr();
2157 }
2158
2159 ciBlock* ciblk = _methodBlocks->block_containing(bci);
2160 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries");
2161 Block* block = get_block_for(ciblk->index(), jsrs, option);
2162
2163 assert(block == NULL? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result");
2164
2165 if (CITraceTypeFlow) {
2166 if (block != NULL) {
2167 tty->print(">> Found block ");
2168 block->print_value_on(tty);
2169 tty->cr();
2170 } else {
2171 tty->print_cr(">> No such block.");
2172 }
2173 }
2174
2175 return block;
2176 }
2177
2178 // ------------------------------------------------------------------
2179 // ciTypeFlow::make_jsr_record
2180 //
2181 // Make a JsrRecord for a given (entry, return) pair, if such a record
2182 // does not already exist.
2183 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address,
2184 int return_address) {
2185 if (_jsr_records == NULL) {
2186 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(),
2187 _jsr_count,
2188 0,
2189 NULL);
2190 }
2191 JsrRecord* record = NULL;
2192 int len = _jsr_records->length();
2193 for (int i = 0; i < len; i++) {
2194 JsrRecord* record = _jsr_records->at(i);
2195 if (record->entry_address() == entry_address &&
2196 record->return_address() == return_address) {
2197 return record;
2198 }
2199 }
2200
2201 record = new (arena()) JsrRecord(entry_address, return_address);
2202 _jsr_records->append(record);
2203 return record;
2204 }
2205
2206 // ------------------------------------------------------------------
2207 // ciTypeFlow::flow_exceptions
2208 //
2209 // Merge the current state into all exceptional successors at the
2210 // current point in the code.
2211 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions,
2212 GrowableArray<ciInstanceKlass*>* exc_klasses,
2213 ciTypeFlow::StateVector* state) {
2214 int len = exceptions->length();
2215 assert(exc_klasses->length() == len, "must have same length");
2216 for (int i = 0; i < len; i++) {
2217 Block* block = exceptions->at(i);
2218 ciInstanceKlass* exception_klass = exc_klasses->at(i);
2219
2220 if (!exception_klass->is_loaded()) {
2221 // Do not compile any code for unloaded exception types.
2222 // Following compiler passes are responsible for doing this also.
2223 continue;
2224 }
2225
2226 if (block->meet_exception(exception_klass, state)) {
2227 // Block was modified and has PO. Add it to the work list.
2228 if (block->has_post_order() &&
2229 !block->is_on_work_list()) {
2230 add_to_work_list(block);
2231 }
2232 }
2233 }
2234 }
2235
2236 // ------------------------------------------------------------------
2237 // ciTypeFlow::flow_successors
2238 //
2239 // Merge the current state into all successors at the current point
2240 // in the code.
2241 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors,
2242 ciTypeFlow::StateVector* state) {
2243 int len = successors->length();
2244 for (int i = 0; i < len; i++) {
2245 Block* block = successors->at(i);
2246 if (block->meet(state)) {
2247 // Block was modified and has PO. Add it to the work list.
2248 if (block->has_post_order() &&
2249 !block->is_on_work_list()) {
2250 add_to_work_list(block);
2251 }
2252 }
2253 }
2254 }
2255
2256 // ------------------------------------------------------------------
2257 // ciTypeFlow::can_trap
2258 //
2259 // Tells if a given instruction is able to generate an exception edge.
2260 bool ciTypeFlow::can_trap(ciBytecodeStream& str) {
2261 // Cf. GenerateOopMap::do_exception_edge.
2262 if (!Bytecodes::can_trap(str.cur_bc())) return false;
2263
2264 switch (str.cur_bc()) {
2265 // %%% FIXME: ldc of Class can generate an exception
2266 case Bytecodes::_ldc:
2267 case Bytecodes::_ldc_w:
2268 case Bytecodes::_ldc2_w:
2269 case Bytecodes::_aload_0:
2270 // These bytecodes can trap for rewriting. We need to assume that
2271 // they do not throw exceptions to make the monitor analysis work.
2272 return false;
2273
2274 case Bytecodes::_ireturn:
2275 case Bytecodes::_lreturn:
2276 case Bytecodes::_freturn:
2277 case Bytecodes::_dreturn:
2278 case Bytecodes::_areturn:
2279 case Bytecodes::_return:
2280 // We can assume the monitor stack is empty in this analysis.
2281 return false;
2282
2283 case Bytecodes::_monitorexit:
2284 // We can assume monitors are matched in this analysis.
2285 return false;
2286
2287 default:
2288 return true;
2289 }
2290 }
2291
2292 // ------------------------------------------------------------------
2293 // ciTypeFlow::clone_loop_heads
2294 //
2295 // Clone the loop heads
2296 bool ciTypeFlow::clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2297 bool rslt = false;
2298 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) {
2299 lp = iter.current();
2300 Block* head = lp->head();
2301 if (lp == loop_tree_root() ||
2302 lp->is_irreducible() ||
2303 !head->is_clonable_exit(lp))
2304 continue;
2305
2306 // Avoid BoxLock merge.
2307 if (EliminateNestedLocks && head->has_monitorenter())
2308 continue;
2309
2310 // check not already cloned
2311 if (head->backedge_copy_count() != 0)
2312 continue;
2313
2314 // Don't clone head of OSR loop to get correct types in start block.
2315 if (is_osr_flow() && head->start() == start_bci())
2316 continue;
2317
2318 // check _no_ shared head below us
2319 Loop* ch;
2320 for (ch = lp->child(); ch != NULL && ch->head() != head; ch = ch->sibling());
2321 if (ch != NULL)
2322 continue;
2323
2324 // Clone head
2325 Block* new_head = head->looping_succ(lp);
2326 Block* clone = clone_loop_head(lp, temp_vector, temp_set);
2327 // Update lp's info
2328 clone->set_loop(lp);
2329 lp->set_head(new_head);
2330 lp->set_tail(clone);
2331 // And move original head into outer loop
2332 head->set_loop(lp->parent());
2333
2334 rslt = true;
2335 }
2336 return rslt;
2337 }
2338
2339 // ------------------------------------------------------------------
2340 // ciTypeFlow::clone_loop_head
2341 //
2342 // Clone lp's head and replace tail's successors with clone.
2343 //
2344 // |
2345 // v
2346 // head <-> body
2347 // |
2348 // v
2349 // exit
2350 //
2351 // new_head
2352 //
2353 // |
2354 // v
2355 // head ----------\
2356 // | |
2357 // | v
2358 // | clone <-> body
2359 // | |
2360 // | /--/
2361 // | |
2362 // v v
2363 // exit
2364 //
2365 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) {
2366 Block* head = lp->head();
2367 Block* tail = lp->tail();
2368 if (CITraceTypeFlow) {
2369 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty);
2370 tty->print(" for predecessor "); tail->print_value_on(tty);
2371 tty->cr();
2372 }
2373 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy);
2374 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges");
2375
2376 assert(!clone->has_pre_order(), "just created");
2377 clone->set_next_pre_order();
2378
2379 // Insert clone after (orig) tail in reverse post order
2380 clone->set_rpo_next(tail->rpo_next());
2381 tail->set_rpo_next(clone);
2382
2383 // tail->head becomes tail->clone
2384 for (SuccIter iter(tail); !iter.done(); iter.next()) {
2385 if (iter.succ() == head) {
2386 iter.set_succ(clone);
2387 // Update predecessor information
2388 head->predecessors()->remove(tail);
2389 clone->predecessors()->append(tail);
2390 }
2391 }
2392 flow_block(tail, temp_vector, temp_set);
2393 if (head == tail) {
2394 // For self-loops, clone->head becomes clone->clone
2395 flow_block(clone, temp_vector, temp_set);
2396 for (SuccIter iter(clone); !iter.done(); iter.next()) {
2397 if (iter.succ() == head) {
2398 iter.set_succ(clone);
2399 // Update predecessor information
2400 head->predecessors()->remove(clone);
2401 clone->predecessors()->append(clone);
2402 break;
2403 }
2404 }
2405 }
2406 flow_block(clone, temp_vector, temp_set);
2407
2408 return clone;
2409 }
2410
2411 // ------------------------------------------------------------------
2412 // ciTypeFlow::flow_block
2413 //
2414 // Interpret the effects of the bytecodes on the incoming state
2415 // vector of a basic block. Push the changed state to succeeding
2416 // basic blocks.
2417 void ciTypeFlow::flow_block(ciTypeFlow::Block* block,
2418 ciTypeFlow::StateVector* state,
2419 ciTypeFlow::JsrSet* jsrs) {
2420 if (CITraceTypeFlow) {
2421 tty->print("\n>> ANALYZING BLOCK : ");
2422 tty->cr();
2423 block->print_on(tty);
2424 }
2425 assert(block->has_pre_order(), "pre-order is assigned before 1st flow");
2426
2427 int start = block->start();
2428 int limit = block->limit();
2429 int control = block->control();
2430 if (control != ciBlock::fall_through_bci) {
2431 limit = control;
2432 }
2433
2434 // Grab the state from the current block.
2435 block->copy_state_into(state);
2436 state->def_locals()->clear();
2437
2438 GrowableArray<Block*>* exceptions = block->exceptions();
2439 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses();
2440 bool has_exceptions = exceptions->length() > 0;
2441
2442 bool exceptions_used = false;
2443
2444 ciBytecodeStream str(method());
2445 str.reset_to_bci(start);
2446 Bytecodes::Code code;
2447 while ((code = str.next()) != ciBytecodeStream::EOBC() &&
2448 str.cur_bci() < limit) {
2449 // Check for exceptional control flow from this point.
2450 if (has_exceptions && can_trap(str)) {
2451 flow_exceptions(exceptions, exc_klasses, state);
2452 exceptions_used = true;
2453 }
2454 // Apply the effects of the current bytecode to our state.
2455 bool res = state->apply_one_bytecode(&str);
2456
2457 // Watch for bailouts.
2458 if (failing()) return;
2459
2460 if (str.cur_bc() == Bytecodes::_monitorenter) {
2461 block->set_has_monitorenter();
2462 }
2463
2464 if (res) {
2465
2466 // We have encountered a trap. Record it in this block.
2467 block->set_trap(state->trap_bci(), state->trap_index());
2468
2469 if (CITraceTypeFlow) {
2470 tty->print_cr(">> Found trap");
2471 block->print_on(tty);
2472 }
2473
2474 // Save set of locals defined in this block
2475 block->def_locals()->add(state->def_locals());
2476
2477 // Record (no) successors.
2478 block->successors(&str, state, jsrs);
2479
2480 assert(!has_exceptions || exceptions_used, "Not removing exceptions");
2481
2482 // Discontinue interpretation of this Block.
2483 return;
2484 }
2485 }
2486
2487 GrowableArray<Block*>* successors = NULL;
2488 if (control != ciBlock::fall_through_bci) {
2489 // Check for exceptional control flow from this point.
2490 if (has_exceptions && can_trap(str)) {
2491 flow_exceptions(exceptions, exc_klasses, state);
2492 exceptions_used = true;
2493 }
2494
2495 // Fix the JsrSet to reflect effect of the bytecode.
2496 block->copy_jsrs_into(jsrs);
2497 jsrs->apply_control(this, &str, state);
2498
2499 // Find successor edges based on old state and new JsrSet.
2500 successors = block->successors(&str, state, jsrs);
2501
2502 // Apply the control changes to the state.
2503 state->apply_one_bytecode(&str);
2504 } else {
2505 // Fall through control
2506 successors = block->successors(&str, NULL, NULL);
2507 }
2508
2509 // Save set of locals defined in this block
2510 block->def_locals()->add(state->def_locals());
2511
2512 // Remove untaken exception paths
2513 if (!exceptions_used)
2514 exceptions->clear();
2515
2516 // Pass our state to successors.
2517 flow_successors(successors, state);
2518 }
2519
2520 // ------------------------------------------------------------------
2521 // ciTypeFlow::PostOrderLoops::next
2522 //
2523 // Advance to next loop tree using a postorder, left-to-right traversal.
2524 void ciTypeFlow::PostorderLoops::next() {
2525 assert(!done(), "must not be done.");
2526 if (_current->sibling() != NULL) {
2527 _current = _current->sibling();
2528 while (_current->child() != NULL) {
2529 _current = _current->child();
2530 }
2531 } else {
2532 _current = _current->parent();
2533 }
2534 }
2535
2536 // ------------------------------------------------------------------
2537 // ciTypeFlow::PreOrderLoops::next
2538 //
2539 // Advance to next loop tree using a preorder, left-to-right traversal.
2540 void ciTypeFlow::PreorderLoops::next() {
2541 assert(!done(), "must not be done.");
2542 if (_current->child() != NULL) {
2543 _current = _current->child();
2544 } else if (_current->sibling() != NULL) {
2545 _current = _current->sibling();
2546 } else {
2547 while (_current != _root && _current->sibling() == NULL) {
2548 _current = _current->parent();
2549 }
2550 if (_current == _root) {
2551 _current = NULL;
2552 assert(done(), "must be done.");
2553 } else {
2554 assert(_current->sibling() != NULL, "must be more to do");
2555 _current = _current->sibling();
2556 }
2557 }
2558 }
2559
2560 // ------------------------------------------------------------------
2561 // ciTypeFlow::Loop::sorted_merge
2562 //
2563 // Merge the branch lp into this branch, sorting on the loop head
2564 // pre_orders. Returns the leaf of the merged branch.
2565 // Child and sibling pointers will be setup later.
2566 // Sort is (looking from leaf towards the root)
2567 // descending on primary key: loop head's pre_order, and
2568 // ascending on secondary key: loop tail's pre_order.
2569 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) {
2570 Loop* leaf = this;
2571 Loop* prev = NULL;
2572 Loop* current = leaf;
2573 while (lp != NULL) {
2574 int lp_pre_order = lp->head()->pre_order();
2575 // Find insertion point for "lp"
2576 while (current != NULL) {
2577 if (current == lp)
2578 return leaf; // Already in list
2579 if (current->head()->pre_order() < lp_pre_order)
2580 break;
2581 if (current->head()->pre_order() == lp_pre_order &&
2582 current->tail()->pre_order() > lp->tail()->pre_order()) {
2583 break;
2584 }
2585 prev = current;
2586 current = current->parent();
2587 }
2588 Loop* next_lp = lp->parent(); // Save future list of items to insert
2589 // Insert lp before current
2590 lp->set_parent(current);
2591 if (prev != NULL) {
2592 prev->set_parent(lp);
2593 } else {
2594 leaf = lp;
2595 }
2596 prev = lp; // Inserted item is new prev[ious]
2597 lp = next_lp; // Next item to insert
2598 }
2599 return leaf;
2600 }
2601
2602 // ------------------------------------------------------------------
2603 // ciTypeFlow::build_loop_tree
2604 //
2605 // Incrementally build loop tree.
2606 void ciTypeFlow::build_loop_tree(Block* blk) {
2607 assert(!blk->is_post_visited(), "precondition");
2608 Loop* innermost = NULL; // merge of loop tree branches over all successors
2609
2610 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2611 Loop* lp = NULL;
2612 Block* succ = iter.succ();
2613 if (!succ->is_post_visited()) {
2614 // Found backedge since predecessor post visited, but successor is not
2615 assert(succ->pre_order() <= blk->pre_order(), "should be backedge");
2616
2617 // Create a LoopNode to mark this loop.
2618 lp = new (arena()) Loop(succ, blk);
2619 if (succ->loop() == NULL)
2620 succ->set_loop(lp);
2621 // succ->loop will be updated to innermost loop on a later call, when blk==succ
2622
2623 } else { // Nested loop
2624 lp = succ->loop();
2625
2626 // If succ is loop head, find outer loop.
2627 while (lp != NULL && lp->head() == succ) {
2628 lp = lp->parent();
2629 }
2630 if (lp == NULL) {
2631 // Infinite loop, it's parent is the root
2632 lp = loop_tree_root();
2633 }
2634 }
2635
2636 // Check for irreducible loop.
2637 // Successor has already been visited. If the successor's loop head
2638 // has already been post-visited, then this is another entry into the loop.
2639 while (lp->head()->is_post_visited() && lp != loop_tree_root()) {
2640 _has_irreducible_entry = true;
2641 lp->set_irreducible(succ);
2642 if (!succ->is_on_work_list()) {
2643 // Assume irreducible entries need more data flow
2644 add_to_work_list(succ);
2645 }
2646 Loop* plp = lp->parent();
2647 if (plp == NULL) {
2648 // This only happens for some irreducible cases. The parent
2649 // will be updated during a later pass.
2650 break;
2651 }
2652 lp = plp;
2653 }
2654
2655 // Merge loop tree branch for all successors.
2656 innermost = innermost == NULL ? lp : innermost->sorted_merge(lp);
2657
2658 } // end loop
2659
2660 if (innermost == NULL) {
2661 assert(blk->successors()->length() == 0, "CFG exit");
2662 blk->set_loop(loop_tree_root());
2663 } else if (innermost->head() == blk) {
2664 // If loop header, complete the tree pointers
2665 if (blk->loop() != innermost) {
2666 #ifdef ASSERT
2667 assert(blk->loop()->head() == innermost->head(), "same head");
2668 Loop* dl;
2669 for (dl = innermost; dl != NULL && dl != blk->loop(); dl = dl->parent());
2670 assert(dl == blk->loop(), "blk->loop() already in innermost list");
2671 #endif
2672 blk->set_loop(innermost);
2673 }
2674 innermost->def_locals()->add(blk->def_locals());
2675 Loop* l = innermost;
2676 Loop* p = l->parent();
2677 while (p && l->head() == blk) {
2678 l->set_sibling(p->child()); // Put self on parents 'next child'
2679 p->set_child(l); // Make self the first child of parent
2680 p->def_locals()->add(l->def_locals());
2681 l = p; // Walk up the parent chain
2682 p = l->parent();
2683 }
2684 } else {
2685 blk->set_loop(innermost);
2686 innermost->def_locals()->add(blk->def_locals());
2687 }
2688 }
2689
2690 // ------------------------------------------------------------------
2691 // ciTypeFlow::Loop::contains
2692 //
2693 // Returns true if lp is nested loop.
2694 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const {
2695 assert(lp != NULL, "");
2696 if (this == lp || head() == lp->head()) return true;
2697 int depth1 = depth();
2698 int depth2 = lp->depth();
2699 if (depth1 > depth2)
2700 return false;
2701 while (depth1 < depth2) {
2702 depth2--;
2703 lp = lp->parent();
2704 }
2705 return this == lp;
2706 }
2707
2708 // ------------------------------------------------------------------
2709 // ciTypeFlow::Loop::depth
2710 //
2711 // Loop depth
2712 int ciTypeFlow::Loop::depth() const {
2713 int dp = 0;
2714 for (Loop* lp = this->parent(); lp != NULL; lp = lp->parent())
2715 dp++;
2716 return dp;
2717 }
2718
2719 #ifndef PRODUCT
2720 // ------------------------------------------------------------------
2721 // ciTypeFlow::Loop::print
2722 void ciTypeFlow::Loop::print(outputStream* st, int indent) const {
2723 for (int i = 0; i < indent; i++) st->print(" ");
2724 st->print("%d<-%d %s",
2725 is_root() ? 0 : this->head()->pre_order(),
2726 is_root() ? 0 : this->tail()->pre_order(),
2727 is_irreducible()?" irr":"");
2728 st->print(" defs: ");
2729 def_locals()->print_on(st, _head->outer()->method()->max_locals());
2730 st->cr();
2731 for (Loop* ch = child(); ch != NULL; ch = ch->sibling())
2732 ch->print(st, indent+2);
2733 }
2734 #endif
2735
2736 // ------------------------------------------------------------------
2737 // ciTypeFlow::df_flow_types
2738 //
2739 // Perform the depth first type flow analysis. Helper for flow_types.
2740 void ciTypeFlow::df_flow_types(Block* start,
2741 bool do_flow,
2742 StateVector* temp_vector,
2743 JsrSet* temp_set) {
2744 int dft_len = 100;
2745 GrowableArray<Block*> stk(dft_len);
2746
2747 ciBlock* dummy = _methodBlocks->make_dummy_block();
2748 JsrSet* root_set = new JsrSet(NULL, 0);
2749 Block* root_head = new (arena()) Block(this, dummy, root_set);
2750 Block* root_tail = new (arena()) Block(this, dummy, root_set);
2751 root_head->set_pre_order(0);
2752 root_head->set_post_order(0);
2753 root_tail->set_pre_order(max_jint);
2754 root_tail->set_post_order(max_jint);
2755 set_loop_tree_root(new (arena()) Loop(root_head, root_tail));
2756
2757 stk.push(start);
2758
2759 _next_pre_order = 0; // initialize pre_order counter
2760 _rpo_list = NULL;
2761 int next_po = 0; // initialize post_order counter
2762
2763 // Compute RPO and the control flow graph
2764 int size;
2765 while ((size = stk.length()) > 0) {
2766 Block* blk = stk.top(); // Leave node on stack
2767 if (!blk->is_visited()) {
2768 // forward arc in graph
2769 assert (!blk->has_pre_order(), "");
2770 blk->set_next_pre_order();
2771
2772 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) {
2773 // Too many basic blocks. Bail out.
2774 // This can happen when try/finally constructs are nested to depth N,
2775 // and there is O(2**N) cloning of jsr bodies. See bug 4697245!
2776 // "MaxNodeLimit / 2" is used because probably the parser will
2777 // generate at least twice that many nodes and bail out.
2778 record_failure("too many basic blocks");
2779 return;
2780 }
2781 if (do_flow) {
2782 flow_block(blk, temp_vector, temp_set);
2783 if (failing()) return; // Watch for bailouts.
2784 }
2785 } else if (!blk->is_post_visited()) {
2786 // cross or back arc
2787 for (SuccIter iter(blk); !iter.done(); iter.next()) {
2788 Block* succ = iter.succ();
2789 if (!succ->is_visited()) {
2790 stk.push(succ);
2791 }
2792 }
2793 if (stk.length() == size) {
2794 // There were no additional children, post visit node now
2795 stk.pop(); // Remove node from stack
2796
2797 build_loop_tree(blk);
2798 blk->set_post_order(next_po++); // Assign post order
2799 prepend_to_rpo_list(blk);
2800 assert(blk->is_post_visited(), "");
2801
2802 if (blk->is_loop_head() && !blk->is_on_work_list()) {
2803 // Assume loop heads need more data flow
2804 add_to_work_list(blk);
2805 }
2806 }
2807 } else {
2808 stk.pop(); // Remove post-visited node from stack
2809 }
2810 }
2811 }
2812
2813 // ------------------------------------------------------------------
2814 // ciTypeFlow::flow_types
2815 //
2816 // Perform the type flow analysis, creating and cloning Blocks as
2817 // necessary.
2818 void ciTypeFlow::flow_types() {
2819 ResourceMark rm;
2820 StateVector* temp_vector = new StateVector(this);
2821 JsrSet* temp_set = new JsrSet(NULL, 16);
2822
2823 // Create the method entry block.
2824 Block* start = block_at(start_bci(), temp_set);
2825
2826 // Load the initial state into it.
2827 const StateVector* start_state = get_start_state();
2828 if (failing()) return;
2829 start->meet(start_state);
2830
2831 // Depth first visit
2832 df_flow_types(start, true /*do flow*/, temp_vector, temp_set);
2833
2834 if (failing()) return;
2835 assert(_rpo_list == start, "must be start");
2836
2837 // Any loops found?
2838 if (loop_tree_root()->child() != NULL &&
2839 env()->comp_level() >= CompLevel_full_optimization) {
2840 // Loop optimizations are not performed on Tier1 compiles.
2841
2842 bool changed = clone_loop_heads(loop_tree_root(), temp_vector, temp_set);
2843
2844 // If some loop heads were cloned, recompute postorder and loop tree
2845 if (changed) {
2846 loop_tree_root()->set_child(NULL);
2847 for (Block* blk = _rpo_list; blk != NULL;) {
2848 Block* next = blk->rpo_next();
2849 blk->df_init();
2850 blk = next;
2851 }
2852 df_flow_types(start, false /*no flow*/, temp_vector, temp_set);
2853 }
2854 }
2855
2856 if (CITraceTypeFlow) {
2857 tty->print_cr("\nLoop tree");
2858 loop_tree_root()->print();
2859 }
2860
2861 // Continue flow analysis until fixed point reached
2862
2863 debug_only(int max_block = _next_pre_order;)
2864
2865 while (!work_list_empty()) {
2866 Block* blk = work_list_next();
2867 assert (blk->has_post_order(), "post order assigned above");
2868
2869 flow_block(blk, temp_vector, temp_set);
2870
2871 assert (max_block == _next_pre_order, "no new blocks");
2872 assert (!failing(), "no more bailouts");
2873 }
2874 }
2875
2876 // ------------------------------------------------------------------
2877 // ciTypeFlow::map_blocks
2878 //
2879 // Create the block map, which indexes blocks in reverse post-order.
2880 void ciTypeFlow::map_blocks() {
2881 assert(_block_map == NULL, "single initialization");
2882 int block_ct = _next_pre_order;
2883 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct);
2884 assert(block_ct == block_count(), "");
2885
2886 Block* blk = _rpo_list;
2887 for (int m = 0; m < block_ct; m++) {
2888 int rpo = blk->rpo();
2889 assert(rpo == m, "should be sequential");
2890 _block_map[rpo] = blk;
2891 blk = blk->rpo_next();
2892 }
2893 assert(blk == NULL, "should be done");
2894
2895 for (int j = 0; j < block_ct; j++) {
2896 assert(_block_map[j] != NULL, "must not drop any blocks");
2897 Block* block = _block_map[j];
2898 // Remove dead blocks from successor lists:
2899 for (int e = 0; e <= 1; e++) {
2900 GrowableArray<Block*>* l = e? block->exceptions(): block->successors();
2901 for (int k = 0; k < l->length(); k++) {
2902 Block* s = l->at(k);
2903 if (!s->has_post_order()) {
2904 if (CITraceTypeFlow) {
2905 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order());
2906 s->print_value_on(tty);
2907 tty->cr();
2908 }
2909 l->remove(s);
2910 --k;
2911 }
2912 }
2913 }
2914 }
2915 }
2916
2917 // ------------------------------------------------------------------
2918 // ciTypeFlow::get_block_for
2919 //
2920 // Find a block with this ciBlock which has a compatible JsrSet.
2921 // If no such block exists, create it, unless the option is no_create.
2922 // If the option is create_backedge_copy, always create a fresh backedge copy.
2923 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) {
2924 Arena* a = arena();
2925 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2926 if (blocks == NULL) {
2927 // Query only?
2928 if (option == no_create) return NULL;
2929
2930 // Allocate the growable array.
2931 blocks = new (a) GrowableArray<Block*>(a, 4, 0, NULL);
2932 _idx_to_blocklist[ciBlockIndex] = blocks;
2933 }
2934
2935 if (option != create_backedge_copy) {
2936 int len = blocks->length();
2937 for (int i = 0; i < len; i++) {
2938 Block* block = blocks->at(i);
2939 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2940 return block;
2941 }
2942 }
2943 }
2944
2945 // Query only?
2946 if (option == no_create) return NULL;
2947
2948 // We did not find a compatible block. Create one.
2949 Block* new_block = new (a) Block(this, _methodBlocks->block(ciBlockIndex), jsrs);
2950 if (option == create_backedge_copy) new_block->set_backedge_copy(true);
2951 blocks->append(new_block);
2952 return new_block;
2953 }
2954
2955 // ------------------------------------------------------------------
2956 // ciTypeFlow::backedge_copy_count
2957 //
2958 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const {
2959 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex];
2960
2961 if (blocks == NULL) {
2962 return 0;
2963 }
2964
2965 int count = 0;
2966 int len = blocks->length();
2967 for (int i = 0; i < len; i++) {
2968 Block* block = blocks->at(i);
2969 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) {
2970 count++;
2971 }
2972 }
2973
2974 return count;
2975 }
2976
2977 // ------------------------------------------------------------------
2978 // ciTypeFlow::do_flow
2979 //
2980 // Perform type inference flow analysis.
2981 void ciTypeFlow::do_flow() {
2982 if (CITraceTypeFlow) {
2983 tty->print_cr("\nPerforming flow analysis on method");
2984 method()->print();
2985 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci());
2986 tty->cr();
2987 method()->print_codes();
2988 }
2989 if (CITraceTypeFlow) {
2990 tty->print_cr("Initial CI Blocks");
2991 print_on(tty);
2992 }
2993 flow_types();
2994 // Watch for bailouts.
2995 if (failing()) {
2996 return;
2997 }
2998
2999 map_blocks();
3000
3001 if (CIPrintTypeFlow || CITraceTypeFlow) {
3002 rpo_print_on(tty);
3003 }
3004 }
3005
3006 // ------------------------------------------------------------------
3007 // ciTypeFlow::is_dominated_by
3008 //
3009 // Determine if the instruction at bci is dominated by the instruction at dom_bci.
3010 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) {
3011 assert(!method()->has_jsrs(), "jsrs are not supported");
3012
3013 ResourceMark rm;
3014 JsrSet* jsrs = new ciTypeFlow::JsrSet(NULL);
3015 int index = _methodBlocks->block_containing(bci)->index();
3016 int dom_index = _methodBlocks->block_containing(dom_bci)->index();
3017 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create);
3018 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create);
3019
3020 // Start block dominates all other blocks
3021 if (start_block()->rpo() == dom_block->rpo()) {
3022 return true;
3023 }
3024
3025 // Dominated[i] is true if block i is dominated by dom_block
3026 int num_blocks = block_count();
3027 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks);
3028 for (int i = 0; i < num_blocks; ++i) {
3029 dominated[i] = true;
3030 }
3031 dominated[start_block()->rpo()] = false;
3032
3033 // Iterative dominator algorithm
3034 bool changed = true;
3035 while (changed) {
3036 changed = false;
3037 // Use reverse postorder iteration
3038 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3039 if (blk->is_start()) {
3040 // Ignore start block
3041 continue;
3042 }
3043 // The block is dominated if it is the dominating block
3044 // itself or if all predecessors are dominated.
3045 int index = blk->rpo();
3046 bool dom = (index == dom_block->rpo());
3047 if (!dom) {
3048 // Check if all predecessors are dominated
3049 dom = true;
3050 for (int i = 0; i < blk->predecessors()->length(); ++i) {
3051 Block* pred = blk->predecessors()->at(i);
3052 if (!dominated[pred->rpo()]) {
3053 dom = false;
3054 break;
3055 }
3056 }
3057 }
3058 // Update dominator information
3059 if (dominated[index] != dom) {
3060 changed = true;
3061 dominated[index] = dom;
3062 }
3063 }
3064 }
3065 // block dominated by dom_block?
3066 return dominated[block->rpo()];
3067 }
3068
3069 // ------------------------------------------------------------------
3070 // ciTypeFlow::record_failure()
3071 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv.
3072 // This is required because there is not a 1-1 relation between the ciEnv and
3073 // the TypeFlow passes within a compilation task. For example, if the compiler
3074 // is considering inlining a method, it will request a TypeFlow. If that fails,
3075 // the compilation as a whole may continue without the inlining. Some TypeFlow
3076 // requests are not optional; if they fail the requestor is responsible for
3077 // copying the failure reason up to the ciEnv. (See Parse::Parse.)
3078 void ciTypeFlow::record_failure(const char* reason) {
3079 if (env()->log() != NULL) {
3080 env()->log()->elem("failure reason='%s' phase='typeflow'", reason);
3081 }
3082 if (_failure_reason == NULL) {
3083 // Record the first failure reason.
3084 _failure_reason = reason;
3085 }
3086 }
3087
3088 ciType* ciTypeFlow::mark_as_never_null(ciType* type) {
3089 // Wrap the type to carry the information that it is never null
3090 return new (arena()) ciWrapper(type, /* never_null */ true);
3091 }
3092
3093 #ifndef PRODUCT
3094 // ------------------------------------------------------------------
3095 // ciTypeFlow::print_on
3096 void ciTypeFlow::print_on(outputStream* st) const {
3097 // Walk through CI blocks
3098 st->print_cr("********************************************************");
3099 st->print ("TypeFlow for ");
3100 method()->name()->print_symbol_on(st);
3101 int limit_bci = code_size();
3102 st->print_cr(" %d bytes", limit_bci);
3103 ciMethodBlocks *mblks = _methodBlocks;
3104 ciBlock* current = NULL;
3105 for (int bci = 0; bci < limit_bci; bci++) {
3106 ciBlock* blk = mblks->block_containing(bci);
3107 if (blk != NULL && blk != current) {
3108 current = blk;
3109 current->print_on(st);
3110
3111 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()];
3112 int num_blocks = (blocks == NULL) ? 0 : blocks->length();
3113
3114 if (num_blocks == 0) {
3115 st->print_cr(" No Blocks");
3116 } else {
3117 for (int i = 0; i < num_blocks; i++) {
3118 Block* block = blocks->at(i);
3119 block->print_on(st);
3120 }
3121 }
3122 st->print_cr("--------------------------------------------------------");
3123 st->cr();
3124 }
3125 }
3126 st->print_cr("********************************************************");
3127 st->cr();
3128 }
3129
3130 void ciTypeFlow::rpo_print_on(outputStream* st) const {
3131 st->print_cr("********************************************************");
3132 st->print ("TypeFlow for ");
3133 method()->name()->print_symbol_on(st);
3134 int limit_bci = code_size();
3135 st->print_cr(" %d bytes", limit_bci);
3136 for (Block* blk = _rpo_list; blk != NULL; blk = blk->rpo_next()) {
3137 blk->print_on(st);
3138 st->print_cr("--------------------------------------------------------");
3139 st->cr();
3140 }
3141 st->print_cr("********************************************************");
3142 st->cr();
3143 }
3144 #endif