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src/share/vm/c1/c1_Instruction.cpp@37c18711a0df
src/share/vm/c1/c1_Instruction.cpp
Mon, 04 Feb 2013 09:11:21 +0100
- author
- roland
- date
- Mon, 04 Feb 2013 09:11:21 +0100
- changeset 4536
- 37c18711a0df
- parent 4037
- da91efe96a93
- child 4860
- 46f6f063b272
- permissions
- -rw-r--r--
8005114: VM is crashing in ciKlass*ciObjArrayKlass::element_klass() if metaspaces are full
Summary: missing test for loaded klass in c1
Reviewed-by: kvn
1 /*
2 * Copyright (c) 1999, 2012, 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 */
25 #include "precompiled.hpp"
26 #include "c1/c1_IR.hpp"
27 #include "c1/c1_Instruction.hpp"
28 #include "c1/c1_InstructionPrinter.hpp"
29 #include "c1/c1_ValueStack.hpp"
30 #include "ci/ciObjArrayKlass.hpp"
31 #include "ci/ciTypeArrayKlass.hpp"
34 // Implementation of Instruction
37 Instruction::Condition Instruction::mirror(Condition cond) {
38 switch (cond) {
39 case eql: return eql;
40 case neq: return neq;
41 case lss: return gtr;
42 case leq: return geq;
43 case gtr: return lss;
44 case geq: return leq;
45 }
46 ShouldNotReachHere();
47 return eql;
48 }
51 Instruction::Condition Instruction::negate(Condition cond) {
52 switch (cond) {
53 case eql: return neq;
54 case neq: return eql;
55 case lss: return geq;
56 case leq: return gtr;
57 case gtr: return leq;
58 case geq: return lss;
59 }
60 ShouldNotReachHere();
61 return eql;
62 }
64 void Instruction::update_exception_state(ValueStack* state) {
65 if (state != NULL && (state->kind() == ValueStack::EmptyExceptionState || state->kind() == ValueStack::ExceptionState)) {
66 assert(state->kind() == ValueStack::EmptyExceptionState || Compilation::current()->env()->jvmti_can_access_local_variables(), "unexpected state kind");
67 _exception_state = state;
68 } else {
69 _exception_state = NULL;
70 }
71 }
74 Instruction* Instruction::prev(BlockBegin* block) {
75 Instruction* p = NULL;
76 Instruction* q = block;
77 while (q != this) {
78 assert(q != NULL, "this is not in the block's instruction list");
79 p = q; q = q->next();
80 }
81 return p;
82 }
85 void Instruction::state_values_do(ValueVisitor* f) {
86 if (state_before() != NULL) {
87 state_before()->values_do(f);
88 }
89 if (exception_state() != NULL){
90 exception_state()->values_do(f);
91 }
92 }
95 #ifndef PRODUCT
96 void Instruction::check_state(ValueStack* state) {
97 if (state != NULL) {
98 state->verify();
99 }
100 }
103 void Instruction::print() {
104 InstructionPrinter ip;
105 print(ip);
106 }
109 void Instruction::print_line() {
110 InstructionPrinter ip;
111 ip.print_line(this);
112 }
115 void Instruction::print(InstructionPrinter& ip) {
116 ip.print_head();
117 ip.print_line(this);
118 tty->cr();
119 }
120 #endif // PRODUCT
123 // perform constant and interval tests on index value
124 bool AccessIndexed::compute_needs_range_check() {
125 Constant* clength = length()->as_Constant();
126 Constant* cindex = index()->as_Constant();
127 if (clength && cindex) {
128 IntConstant* l = clength->type()->as_IntConstant();
129 IntConstant* i = cindex->type()->as_IntConstant();
130 if (l && i && i->value() < l->value() && i->value() >= 0) {
131 return false;
132 }
133 }
134 return true;
135 }
138 ciType* Local::exact_type() const {
139 ciType* type = declared_type();
141 // for primitive arrays, the declared type is the exact type
142 if (type->is_type_array_klass()) {
143 return type;
144 } else if (type->is_instance_klass()) {
145 ciInstanceKlass* ik = (ciInstanceKlass*)type;
146 if (ik->is_loaded() && ik->is_final() && !ik->is_interface()) {
147 return type;
148 }
149 } else if (type->is_obj_array_klass()) {
150 ciObjArrayKlass* oak = (ciObjArrayKlass*)type;
151 ciType* base = oak->base_element_type();
152 if (base->is_instance_klass()) {
153 ciInstanceKlass* ik = base->as_instance_klass();
154 if (ik->is_loaded() && ik->is_final()) {
155 return type;
156 }
157 } else if (base->is_primitive_type()) {
158 return type;
159 }
160 }
161 return NULL;
162 }
164 ciType* Constant::exact_type() const {
165 if (type()->is_object()) {
166 return type()->as_ObjectType()->exact_type();
167 }
168 return NULL;
169 }
171 ciType* LoadIndexed::exact_type() const {
172 ciType* array_type = array()->exact_type();
173 if (array_type == NULL) {
174 return NULL;
175 }
176 assert(array_type->is_array_klass(), "what else?");
177 ciArrayKlass* ak = (ciArrayKlass*)array_type;
179 if (ak->element_type()->is_instance_klass()) {
180 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
181 if (ik->is_loaded() && ik->is_final()) {
182 return ik;
183 }
184 }
185 return NULL;
186 }
189 ciType* LoadIndexed::declared_type() const {
190 ciType* array_type = array()->declared_type();
191 if (array_type == NULL || !array_type->is_loaded()) {
192 return NULL;
193 }
194 assert(array_type->is_array_klass(), "what else?");
195 ciArrayKlass* ak = (ciArrayKlass*)array_type;
196 return ak->element_type();
197 }
200 ciType* LoadField::declared_type() const {
201 return field()->type();
202 }
205 ciType* LoadField::exact_type() const {
206 ciType* type = declared_type();
207 // for primitive arrays, the declared type is the exact type
208 if (type->is_type_array_klass()) {
209 return type;
210 }
211 if (type->is_instance_klass()) {
212 ciInstanceKlass* ik = (ciInstanceKlass*)type;
213 if (ik->is_loaded() && ik->is_final()) {
214 return type;
215 }
216 }
217 return NULL;
218 }
221 ciType* NewTypeArray::exact_type() const {
222 return ciTypeArrayKlass::make(elt_type());
223 }
225 ciType* NewObjectArray::exact_type() const {
226 return ciObjArrayKlass::make(klass());
227 }
229 ciType* NewArray::declared_type() const {
230 return exact_type();
231 }
233 ciType* NewInstance::exact_type() const {
234 return klass();
235 }
237 ciType* NewInstance::declared_type() const {
238 return exact_type();
239 }
241 ciType* CheckCast::declared_type() const {
242 return klass();
243 }
245 ciType* CheckCast::exact_type() const {
246 if (klass()->is_instance_klass()) {
247 ciInstanceKlass* ik = (ciInstanceKlass*)klass();
248 if (ik->is_loaded() && ik->is_final()) {
249 return ik;
250 }
251 }
252 return NULL;
253 }
255 // Implementation of ArithmeticOp
257 bool ArithmeticOp::is_commutative() const {
258 switch (op()) {
259 case Bytecodes::_iadd: // fall through
260 case Bytecodes::_ladd: // fall through
261 case Bytecodes::_fadd: // fall through
262 case Bytecodes::_dadd: // fall through
263 case Bytecodes::_imul: // fall through
264 case Bytecodes::_lmul: // fall through
265 case Bytecodes::_fmul: // fall through
266 case Bytecodes::_dmul: return true;
267 }
268 return false;
269 }
272 bool ArithmeticOp::can_trap() const {
273 switch (op()) {
274 case Bytecodes::_idiv: // fall through
275 case Bytecodes::_ldiv: // fall through
276 case Bytecodes::_irem: // fall through
277 case Bytecodes::_lrem: return true;
278 }
279 return false;
280 }
283 // Implementation of LogicOp
285 bool LogicOp::is_commutative() const {
286 #ifdef ASSERT
287 switch (op()) {
288 case Bytecodes::_iand: // fall through
289 case Bytecodes::_land: // fall through
290 case Bytecodes::_ior : // fall through
291 case Bytecodes::_lor : // fall through
292 case Bytecodes::_ixor: // fall through
293 case Bytecodes::_lxor: break;
294 default : ShouldNotReachHere();
295 }
296 #endif
297 // all LogicOps are commutative
298 return true;
299 }
302 // Implementation of IfOp
304 bool IfOp::is_commutative() const {
305 return cond() == eql || cond() == neq;
306 }
309 // Implementation of StateSplit
311 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
312 NOT_PRODUCT(bool assigned = false;)
313 for (int i = 0; i < list.length(); i++) {
314 BlockBegin** b = list.adr_at(i);
315 if (*b == old_block) {
316 *b = new_block;
317 NOT_PRODUCT(assigned = true;)
318 }
319 }
320 assert(assigned == true, "should have assigned at least once");
321 }
324 IRScope* StateSplit::scope() const {
325 return _state->scope();
326 }
329 void StateSplit::state_values_do(ValueVisitor* f) {
330 Instruction::state_values_do(f);
331 if (state() != NULL) state()->values_do(f);
332 }
335 void BlockBegin::state_values_do(ValueVisitor* f) {
336 StateSplit::state_values_do(f);
338 if (is_set(BlockBegin::exception_entry_flag)) {
339 for (int i = 0; i < number_of_exception_states(); i++) {
340 exception_state_at(i)->values_do(f);
341 }
342 }
343 }
346 // Implementation of Invoke
349 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
350 int vtable_index, ciMethod* target, ValueStack* state_before)
351 : StateSplit(result_type, state_before)
352 , _code(code)
353 , _recv(recv)
354 , _args(args)
355 , _vtable_index(vtable_index)
356 , _target(target)
357 {
358 set_flag(TargetIsLoadedFlag, target->is_loaded());
359 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
360 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
362 assert(args != NULL, "args must exist");
363 #ifdef ASSERT
364 AssertValues assert_value;
365 values_do(&assert_value);
366 #endif
368 // provide an initial guess of signature size.
369 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
370 if (has_receiver()) {
371 _signature->append(as_BasicType(receiver()->type()));
372 }
373 for (int i = 0; i < number_of_arguments(); i++) {
374 ValueType* t = argument_at(i)->type();
375 BasicType bt = as_BasicType(t);
376 _signature->append(bt);
377 }
378 }
381 void Invoke::state_values_do(ValueVisitor* f) {
382 StateSplit::state_values_do(f);
383 if (state_before() != NULL) state_before()->values_do(f);
384 if (state() != NULL) state()->values_do(f);
385 }
387 ciType* Invoke::declared_type() const {
388 ciType *t = _target->signature()->return_type();
389 assert(t->basic_type() != T_VOID, "need return value of void method?");
390 return t;
391 }
393 // Implementation of Contant
394 intx Constant::hash() const {
395 if (state_before() == NULL) {
396 switch (type()->tag()) {
397 case intTag:
398 return HASH2(name(), type()->as_IntConstant()->value());
399 case addressTag:
400 return HASH2(name(), type()->as_AddressConstant()->value());
401 case longTag:
402 {
403 jlong temp = type()->as_LongConstant()->value();
404 return HASH3(name(), high(temp), low(temp));
405 }
406 case floatTag:
407 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
408 case doubleTag:
409 {
410 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
411 return HASH3(name(), high(temp), low(temp));
412 }
413 case objectTag:
414 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
415 return HASH2(name(), type()->as_ObjectType()->constant_value());
416 case metaDataTag:
417 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
418 return HASH2(name(), type()->as_MetadataType()->constant_value());
419 default:
420 ShouldNotReachHere();
421 }
422 }
423 return 0;
424 }
426 bool Constant::is_equal(Value v) const {
427 if (v->as_Constant() == NULL) return false;
429 switch (type()->tag()) {
430 case intTag:
431 {
432 IntConstant* t1 = type()->as_IntConstant();
433 IntConstant* t2 = v->type()->as_IntConstant();
434 return (t1 != NULL && t2 != NULL &&
435 t1->value() == t2->value());
436 }
437 case longTag:
438 {
439 LongConstant* t1 = type()->as_LongConstant();
440 LongConstant* t2 = v->type()->as_LongConstant();
441 return (t1 != NULL && t2 != NULL &&
442 t1->value() == t2->value());
443 }
444 case floatTag:
445 {
446 FloatConstant* t1 = type()->as_FloatConstant();
447 FloatConstant* t2 = v->type()->as_FloatConstant();
448 return (t1 != NULL && t2 != NULL &&
449 jint_cast(t1->value()) == jint_cast(t2->value()));
450 }
451 case doubleTag:
452 {
453 DoubleConstant* t1 = type()->as_DoubleConstant();
454 DoubleConstant* t2 = v->type()->as_DoubleConstant();
455 return (t1 != NULL && t2 != NULL &&
456 jlong_cast(t1->value()) == jlong_cast(t2->value()));
457 }
458 case objectTag:
459 {
460 ObjectType* t1 = type()->as_ObjectType();
461 ObjectType* t2 = v->type()->as_ObjectType();
462 return (t1 != NULL && t2 != NULL &&
463 t1->is_loaded() && t2->is_loaded() &&
464 t1->constant_value() == t2->constant_value());
465 }
466 case metaDataTag:
467 {
468 MetadataType* t1 = type()->as_MetadataType();
469 MetadataType* t2 = v->type()->as_MetadataType();
470 return (t1 != NULL && t2 != NULL &&
471 t1->is_loaded() && t2->is_loaded() &&
472 t1->constant_value() == t2->constant_value());
473 }
474 }
475 return false;
476 }
478 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
479 Constant* rc = right->as_Constant();
480 // other is not a constant
481 if (rc == NULL) return not_comparable;
483 ValueType* lt = type();
484 ValueType* rt = rc->type();
485 // different types
486 if (lt->base() != rt->base()) return not_comparable;
487 switch (lt->tag()) {
488 case intTag: {
489 int x = lt->as_IntConstant()->value();
490 int y = rt->as_IntConstant()->value();
491 switch (cond) {
492 case If::eql: return x == y ? cond_true : cond_false;
493 case If::neq: return x != y ? cond_true : cond_false;
494 case If::lss: return x < y ? cond_true : cond_false;
495 case If::leq: return x <= y ? cond_true : cond_false;
496 case If::gtr: return x > y ? cond_true : cond_false;
497 case If::geq: return x >= y ? cond_true : cond_false;
498 }
499 break;
500 }
501 case longTag: {
502 jlong x = lt->as_LongConstant()->value();
503 jlong y = rt->as_LongConstant()->value();
504 switch (cond) {
505 case If::eql: return x == y ? cond_true : cond_false;
506 case If::neq: return x != y ? cond_true : cond_false;
507 case If::lss: return x < y ? cond_true : cond_false;
508 case If::leq: return x <= y ? cond_true : cond_false;
509 case If::gtr: return x > y ? cond_true : cond_false;
510 case If::geq: return x >= y ? cond_true : cond_false;
511 }
512 break;
513 }
514 case objectTag: {
515 ciObject* xvalue = lt->as_ObjectType()->constant_value();
516 ciObject* yvalue = rt->as_ObjectType()->constant_value();
517 assert(xvalue != NULL && yvalue != NULL, "not constants");
518 if (xvalue->is_loaded() && yvalue->is_loaded()) {
519 switch (cond) {
520 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
521 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
522 }
523 }
524 break;
525 }
526 case metaDataTag: {
527 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
528 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
529 assert(xvalue != NULL && yvalue != NULL, "not constants");
530 if (xvalue->is_loaded() && yvalue->is_loaded()) {
531 switch (cond) {
532 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
533 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
534 }
535 }
536 break;
537 }
538 }
539 return not_comparable;
540 }
543 // Implementation of BlockBegin
545 void BlockBegin::set_end(BlockEnd* end) {
546 assert(end != NULL, "should not reset block end to NULL");
547 if (end == _end) {
548 return;
549 }
550 clear_end();
552 // Set the new end
553 _end = end;
555 _successors.clear();
556 // Now reset successors list based on BlockEnd
557 for (int i = 0; i < end->number_of_sux(); i++) {
558 BlockBegin* sux = end->sux_at(i);
559 _successors.append(sux);
560 sux->_predecessors.append(this);
561 }
562 _end->set_begin(this);
563 }
566 void BlockBegin::clear_end() {
567 // Must make the predecessors/successors match up with the
568 // BlockEnd's notion.
569 if (_end != NULL) {
570 // disconnect from the old end
571 _end->set_begin(NULL);
573 // disconnect this block from it's current successors
574 for (int i = 0; i < _successors.length(); i++) {
575 _successors.at(i)->remove_predecessor(this);
576 }
577 _end = NULL;
578 }
579 }
582 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
583 // disconnect any edges between from and to
584 #ifndef PRODUCT
585 if (PrintIR && Verbose) {
586 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
587 }
588 #endif
589 for (int s = 0; s < from->number_of_sux();) {
590 BlockBegin* sux = from->sux_at(s);
591 if (sux == to) {
592 int index = sux->_predecessors.index_of(from);
593 if (index >= 0) {
594 sux->_predecessors.remove_at(index);
595 }
596 from->_successors.remove_at(s);
597 } else {
598 s++;
599 }
600 }
601 }
604 void BlockBegin::disconnect_from_graph() {
605 // disconnect this block from all other blocks
606 for (int p = 0; p < number_of_preds(); p++) {
607 pred_at(p)->remove_successor(this);
608 }
609 for (int s = 0; s < number_of_sux(); s++) {
610 sux_at(s)->remove_predecessor(this);
611 }
612 }
614 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
615 // modify predecessors before substituting successors
616 for (int i = 0; i < number_of_sux(); i++) {
617 if (sux_at(i) == old_sux) {
618 // remove old predecessor before adding new predecessor
619 // otherwise there is a dead predecessor in the list
620 new_sux->remove_predecessor(old_sux);
621 new_sux->add_predecessor(this);
622 }
623 }
624 old_sux->remove_predecessor(this);
625 end()->substitute_sux(old_sux, new_sux);
626 }
630 // In general it is not possible to calculate a value for the field "depth_first_number"
631 // of the inserted block, without recomputing the values of the other blocks
632 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
633 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
634 BlockBegin* new_sux = new BlockBegin(end()->state()->bci());
636 // mark this block (special treatment when block order is computed)
637 new_sux->set(critical_edge_split_flag);
639 // This goto is not a safepoint.
640 Goto* e = new Goto(sux, false);
641 new_sux->set_next(e, end()->state()->bci());
642 new_sux->set_end(e);
643 // setup states
644 ValueStack* s = end()->state();
645 new_sux->set_state(s->copy());
646 e->set_state(s->copy());
647 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
648 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
649 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
651 // link predecessor to new block
652 end()->substitute_sux(sux, new_sux);
654 // The ordering needs to be the same, so remove the link that the
655 // set_end call above added and substitute the new_sux for this
656 // block.
657 sux->remove_predecessor(new_sux);
659 // the successor could be the target of a switch so it might have
660 // multiple copies of this predecessor, so substitute the new_sux
661 // for the first and delete the rest.
662 bool assigned = false;
663 BlockList& list = sux->_predecessors;
664 for (int i = 0; i < list.length(); i++) {
665 BlockBegin** b = list.adr_at(i);
666 if (*b == this) {
667 if (assigned) {
668 list.remove_at(i);
669 // reprocess this index
670 i--;
671 } else {
672 assigned = true;
673 *b = new_sux;
674 }
675 // link the new block back to it's predecessors.
676 new_sux->add_predecessor(this);
677 }
678 }
679 assert(assigned == true, "should have assigned at least once");
680 return new_sux;
681 }
684 void BlockBegin::remove_successor(BlockBegin* pred) {
685 int idx;
686 while ((idx = _successors.index_of(pred)) >= 0) {
687 _successors.remove_at(idx);
688 }
689 }
692 void BlockBegin::add_predecessor(BlockBegin* pred) {
693 _predecessors.append(pred);
694 }
697 void BlockBegin::remove_predecessor(BlockBegin* pred) {
698 int idx;
699 while ((idx = _predecessors.index_of(pred)) >= 0) {
700 _predecessors.remove_at(idx);
701 }
702 }
705 void BlockBegin::add_exception_handler(BlockBegin* b) {
706 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
707 // add only if not in the list already
708 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
709 }
711 int BlockBegin::add_exception_state(ValueStack* state) {
712 assert(is_set(exception_entry_flag), "only for xhandlers");
713 if (_exception_states == NULL) {
714 _exception_states = new ValueStackStack(4);
715 }
716 _exception_states->append(state);
717 return _exception_states->length() - 1;
718 }
721 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
722 if (!mark.at(block_id())) {
723 mark.at_put(block_id(), true);
724 closure->block_do(this);
725 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
726 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
727 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
728 }
729 }
732 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
733 if (!mark.at(block_id())) {
734 mark.at_put(block_id(), true);
735 BlockEnd* e = end();
736 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
737 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
738 closure->block_do(this);
739 }
740 }
743 void BlockBegin::iterate_preorder(BlockClosure* closure) {
744 boolArray mark(number_of_blocks(), false);
745 iterate_preorder(mark, closure);
746 }
749 void BlockBegin::iterate_postorder(BlockClosure* closure) {
750 boolArray mark(number_of_blocks(), false);
751 iterate_postorder(mark, closure);
752 }
755 void BlockBegin::block_values_do(ValueVisitor* f) {
756 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
757 }
760 #ifndef PRODUCT
761 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
762 #else
763 #define TRACE_PHI(coce)
764 #endif
767 bool BlockBegin::try_merge(ValueStack* new_state) {
768 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
770 // local variables used for state iteration
771 int index;
772 Value new_value, existing_value;
774 ValueStack* existing_state = state();
775 if (existing_state == NULL) {
776 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
778 if (is_set(BlockBegin::was_visited_flag)) {
779 // this actually happens for complicated jsr/ret structures
780 return false; // BAILOUT in caller
781 }
783 // copy state because it is altered
784 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
786 // Use method liveness to invalidate dead locals
787 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
788 if (liveness.is_valid()) {
789 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
791 for_each_local_value(new_state, index, new_value) {
792 if (!liveness.at(index) || new_value->type()->is_illegal()) {
793 new_state->invalidate_local(index);
794 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
795 }
796 }
797 }
799 if (is_set(BlockBegin::parser_loop_header_flag)) {
800 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
802 for_each_stack_value(new_state, index, new_value) {
803 new_state->setup_phi_for_stack(this, index);
804 TRACE_PHI(tty->print_cr("creating phi-function %c%d for stack %d", new_state->stack_at(index)->type()->tchar(), new_state->stack_at(index)->id(), index));
805 }
807 BitMap requires_phi_function = new_state->scope()->requires_phi_function();
809 for_each_local_value(new_state, index, new_value) {
810 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
811 if (requires_phi || !SelectivePhiFunctions) {
812 new_state->setup_phi_for_local(this, index);
813 TRACE_PHI(tty->print_cr("creating phi-function %c%d for local %d", new_state->local_at(index)->type()->tchar(), new_state->local_at(index)->id(), index));
814 }
815 }
816 }
818 // initialize state of block
819 set_state(new_state);
821 } else if (existing_state->is_same(new_state)) {
822 TRACE_PHI(tty->print_cr("exisiting state found"));
824 assert(existing_state->scope() == new_state->scope(), "not matching");
825 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
826 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
828 if (is_set(BlockBegin::was_visited_flag)) {
829 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
831 if (!is_set(BlockBegin::parser_loop_header_flag)) {
832 // this actually happens for complicated jsr/ret structures
833 return false; // BAILOUT in caller
834 }
836 for_each_local_value(existing_state, index, existing_value) {
837 Value new_value = new_state->local_at(index);
838 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
839 // The old code invalidated the phi function here
840 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
841 return false; // BAILOUT in caller
842 }
843 }
845 #ifdef ASSERT
846 // check that all necessary phi functions are present
847 for_each_stack_value(existing_state, index, existing_value) {
848 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
849 }
850 for_each_local_value(existing_state, index, existing_value) {
851 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
852 }
853 #endif
855 } else {
856 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
858 // create necessary phi functions for stack
859 for_each_stack_value(existing_state, index, existing_value) {
860 Value new_value = new_state->stack_at(index);
861 Phi* existing_phi = existing_value->as_Phi();
863 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
864 existing_state->setup_phi_for_stack(this, index);
865 TRACE_PHI(tty->print_cr("creating phi-function %c%d for stack %d", existing_state->stack_at(index)->type()->tchar(), existing_state->stack_at(index)->id(), index));
866 }
867 }
869 // create necessary phi functions for locals
870 for_each_local_value(existing_state, index, existing_value) {
871 Value new_value = new_state->local_at(index);
872 Phi* existing_phi = existing_value->as_Phi();
874 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
875 existing_state->invalidate_local(index);
876 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
877 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
878 existing_state->setup_phi_for_local(this, index);
879 TRACE_PHI(tty->print_cr("creating phi-function %c%d for local %d", existing_state->local_at(index)->type()->tchar(), existing_state->local_at(index)->id(), index));
880 }
881 }
882 }
884 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
886 } else {
887 assert(false, "stack or locks not matching (invalid bytecodes)");
888 return false;
889 }
891 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
893 return true;
894 }
897 #ifndef PRODUCT
898 void BlockBegin::print_block() {
899 InstructionPrinter ip;
900 print_block(ip, false);
901 }
904 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
905 ip.print_instr(this); tty->cr();
906 ip.print_stack(this->state()); tty->cr();
907 ip.print_inline_level(this);
908 ip.print_head();
909 for (Instruction* n = next(); n != NULL; n = n->next()) {
910 if (!live_only || n->is_pinned() || n->use_count() > 0) {
911 ip.print_line(n);
912 }
913 }
914 tty->cr();
915 }
916 #endif // PRODUCT
919 // Implementation of BlockList
921 void BlockList::iterate_forward (BlockClosure* closure) {
922 const int l = length();
923 for (int i = 0; i < l; i++) closure->block_do(at(i));
924 }
927 void BlockList::iterate_backward(BlockClosure* closure) {
928 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
929 }
932 void BlockList::blocks_do(void f(BlockBegin*)) {
933 for (int i = length() - 1; i >= 0; i--) f(at(i));
934 }
937 void BlockList::values_do(ValueVisitor* f) {
938 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
939 }
942 #ifndef PRODUCT
943 void BlockList::print(bool cfg_only, bool live_only) {
944 InstructionPrinter ip;
945 for (int i = 0; i < length(); i++) {
946 BlockBegin* block = at(i);
947 if (cfg_only) {
948 ip.print_instr(block); tty->cr();
949 } else {
950 block->print_block(ip, live_only);
951 }
952 }
953 }
954 #endif // PRODUCT
957 // Implementation of BlockEnd
959 void BlockEnd::set_begin(BlockBegin* begin) {
960 BlockList* sux = NULL;
961 if (begin != NULL) {
962 sux = begin->successors();
963 } else if (_begin != NULL) {
964 // copy our sux list
965 BlockList* sux = new BlockList(_begin->number_of_sux());
966 for (int i = 0; i < _begin->number_of_sux(); i++) {
967 sux->append(_begin->sux_at(i));
968 }
969 }
970 _sux = sux;
971 _begin = begin;
972 }
975 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
976 substitute(*_sux, old_sux, new_sux);
977 }
980 // Implementation of Phi
982 // Normal phi functions take their operands from the last instruction of the
983 // predecessor. Special handling is needed for xhanlder entries because there
984 // the state of arbitrary instructions are needed.
986 Value Phi::operand_at(int i) const {
987 ValueStack* state;
988 if (_block->is_set(BlockBegin::exception_entry_flag)) {
989 state = _block->exception_state_at(i);
990 } else {
991 state = _block->pred_at(i)->end()->state();
992 }
993 assert(state != NULL, "");
995 if (is_local()) {
996 return state->local_at(local_index());
997 } else {
998 return state->stack_at(stack_index());
999 }
1000 }
1003 int Phi::operand_count() const {
1004 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1005 return _block->number_of_exception_states();
1006 } else {
1007 return _block->number_of_preds();
1008 }
1009 }
1013 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1014 if (state() != NULL) state()->values_do(f);
1015 }
