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src/share/vm/c1/c1_Instruction.cpp@ac27a9c85bea
src/share/vm/c1/c1_Instruction.cpp
Thu, 24 May 2018 18:41:44 +0800
- author
- aoqi
- date
- Thu, 24 May 2018 18:41:44 +0800
- changeset 8856
- ac27a9c85bea
- parent 8652
- 057571442f86
- parent 6876
- 710a3c8b516e
- child 10015
- eb7ce841ccec
- permissions
- -rw-r--r--
Merge
1 /*
2 * Copyright (c) 1999, 2013, 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 int Instruction::dominator_depth() {
38 int result = -1;
39 if (block()) {
40 result = block()->dominator_depth();
41 }
42 assert(result != -1 || this->as_Local(), "Only locals have dominator depth -1");
43 return result;
44 }
46 Instruction::Condition Instruction::mirror(Condition cond) {
47 switch (cond) {
48 case eql: return eql;
49 case neq: return neq;
50 case lss: return gtr;
51 case leq: return geq;
52 case gtr: return lss;
53 case geq: return leq;
54 case aeq: return beq;
55 case beq: return aeq;
56 }
57 ShouldNotReachHere();
58 return eql;
59 }
62 Instruction::Condition Instruction::negate(Condition cond) {
63 switch (cond) {
64 case eql: return neq;
65 case neq: return eql;
66 case lss: return geq;
67 case leq: return gtr;
68 case gtr: return leq;
69 case geq: return lss;
70 case aeq: assert(false, "Above equal cannot be negated");
71 case beq: assert(false, "Below equal cannot be negated");
72 }
73 ShouldNotReachHere();
74 return eql;
75 }
77 void Instruction::update_exception_state(ValueStack* state) {
78 if (state != NULL && (state->kind() == ValueStack::EmptyExceptionState || state->kind() == ValueStack::ExceptionState)) {
79 assert(state->kind() == ValueStack::EmptyExceptionState || Compilation::current()->env()->jvmti_can_access_local_variables(), "unexpected state kind");
80 _exception_state = state;
81 } else {
82 _exception_state = NULL;
83 }
84 }
86 // Prev without need to have BlockBegin
87 Instruction* Instruction::prev() {
88 Instruction* p = NULL;
89 Instruction* q = block();
90 while (q != this) {
91 assert(q != NULL, "this is not in the block's instruction list");
92 p = q; q = q->next();
93 }
94 return p;
95 }
98 void Instruction::state_values_do(ValueVisitor* f) {
99 if (state_before() != NULL) {
100 state_before()->values_do(f);
101 }
102 if (exception_state() != NULL){
103 exception_state()->values_do(f);
104 }
105 }
107 ciType* Instruction::exact_type() const {
108 ciType* t = declared_type();
109 if (t != NULL && t->is_klass()) {
110 return t->as_klass()->exact_klass();
111 }
112 return NULL;
113 }
116 #ifndef PRODUCT
117 void Instruction::check_state(ValueStack* state) {
118 if (state != NULL) {
119 state->verify();
120 }
121 }
124 void Instruction::print() {
125 InstructionPrinter ip;
126 print(ip);
127 }
130 void Instruction::print_line() {
131 InstructionPrinter ip;
132 ip.print_line(this);
133 }
136 void Instruction::print(InstructionPrinter& ip) {
137 ip.print_head();
138 ip.print_line(this);
139 tty->cr();
140 }
141 #endif // PRODUCT
144 // perform constant and interval tests on index value
145 bool AccessIndexed::compute_needs_range_check() {
146 if (length()) {
147 Constant* clength = length()->as_Constant();
148 Constant* cindex = index()->as_Constant();
149 if (clength && cindex) {
150 IntConstant* l = clength->type()->as_IntConstant();
151 IntConstant* i = cindex->type()->as_IntConstant();
152 if (l && i && i->value() < l->value() && i->value() >= 0) {
153 return false;
154 }
155 }
156 }
158 if (!this->check_flag(NeedsRangeCheckFlag)) {
159 return false;
160 }
162 return true;
163 }
166 ciType* Constant::exact_type() const {
167 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) {
168 return type()->as_ObjectType()->exact_type();
169 }
170 return NULL;
171 }
173 ciType* LoadIndexed::exact_type() const {
174 ciType* array_type = array()->exact_type();
175 if (array_type != NULL) {
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 }
186 return Instruction::exact_type();
187 }
190 ciType* LoadIndexed::declared_type() const {
191 ciType* array_type = array()->declared_type();
192 if (array_type == NULL || !array_type->is_loaded()) {
193 return NULL;
194 }
195 assert(array_type->is_array_klass(), "what else?");
196 ciArrayKlass* ak = (ciArrayKlass*)array_type;
197 return ak->element_type();
198 }
201 ciType* LoadField::declared_type() const {
202 return field()->type();
203 }
206 ciType* NewTypeArray::exact_type() const {
207 return ciTypeArrayKlass::make(elt_type());
208 }
210 ciType* NewObjectArray::exact_type() const {
211 return ciObjArrayKlass::make(klass());
212 }
214 ciType* NewArray::declared_type() const {
215 return exact_type();
216 }
218 ciType* NewInstance::exact_type() const {
219 return klass();
220 }
222 ciType* NewInstance::declared_type() const {
223 return exact_type();
224 }
226 ciType* CheckCast::declared_type() const {
227 return klass();
228 }
230 // Implementation of ArithmeticOp
232 bool ArithmeticOp::is_commutative() const {
233 switch (op()) {
234 case Bytecodes::_iadd: // fall through
235 case Bytecodes::_ladd: // fall through
236 case Bytecodes::_fadd: // fall through
237 case Bytecodes::_dadd: // fall through
238 case Bytecodes::_imul: // fall through
239 case Bytecodes::_lmul: // fall through
240 case Bytecodes::_fmul: // fall through
241 case Bytecodes::_dmul: return true;
242 }
243 return false;
244 }
247 bool ArithmeticOp::can_trap() const {
248 switch (op()) {
249 case Bytecodes::_idiv: // fall through
250 case Bytecodes::_ldiv: // fall through
251 case Bytecodes::_irem: // fall through
252 case Bytecodes::_lrem: return true;
253 }
254 return false;
255 }
258 // Implementation of LogicOp
260 bool LogicOp::is_commutative() const {
261 #ifdef ASSERT
262 switch (op()) {
263 case Bytecodes::_iand: // fall through
264 case Bytecodes::_land: // fall through
265 case Bytecodes::_ior : // fall through
266 case Bytecodes::_lor : // fall through
267 case Bytecodes::_ixor: // fall through
268 case Bytecodes::_lxor: break;
269 default : ShouldNotReachHere();
270 }
271 #endif
272 // all LogicOps are commutative
273 return true;
274 }
277 // Implementation of IfOp
279 bool IfOp::is_commutative() const {
280 return cond() == eql || cond() == neq;
281 }
284 // Implementation of StateSplit
286 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
287 NOT_PRODUCT(bool assigned = false;)
288 for (int i = 0; i < list.length(); i++) {
289 BlockBegin** b = list.adr_at(i);
290 if (*b == old_block) {
291 *b = new_block;
292 NOT_PRODUCT(assigned = true;)
293 }
294 }
295 assert(assigned == true, "should have assigned at least once");
296 }
299 IRScope* StateSplit::scope() const {
300 return _state->scope();
301 }
304 void StateSplit::state_values_do(ValueVisitor* f) {
305 Instruction::state_values_do(f);
306 if (state() != NULL) state()->values_do(f);
307 }
310 void BlockBegin::state_values_do(ValueVisitor* f) {
311 StateSplit::state_values_do(f);
313 if (is_set(BlockBegin::exception_entry_flag)) {
314 for (int i = 0; i < number_of_exception_states(); i++) {
315 exception_state_at(i)->values_do(f);
316 }
317 }
318 }
321 // Implementation of Invoke
324 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
325 int vtable_index, ciMethod* target, ValueStack* state_before)
326 : StateSplit(result_type, state_before)
327 , _code(code)
328 , _recv(recv)
329 , _args(args)
330 , _vtable_index(vtable_index)
331 , _target(target)
332 {
333 set_flag(TargetIsLoadedFlag, target->is_loaded());
334 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
335 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
337 assert(args != NULL, "args must exist");
338 #ifdef ASSERT
339 AssertValues assert_value;
340 values_do(&assert_value);
341 #endif
343 // provide an initial guess of signature size.
344 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
345 if (has_receiver()) {
346 _signature->append(as_BasicType(receiver()->type()));
347 }
348 for (int i = 0; i < number_of_arguments(); i++) {
349 ValueType* t = argument_at(i)->type();
350 BasicType bt = as_BasicType(t);
351 _signature->append(bt);
352 }
353 }
356 void Invoke::state_values_do(ValueVisitor* f) {
357 StateSplit::state_values_do(f);
358 if (state_before() != NULL) state_before()->values_do(f);
359 if (state() != NULL) state()->values_do(f);
360 }
362 ciType* Invoke::declared_type() const {
363 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci());
364 ciType *t = declared_signature->return_type();
365 assert(t->basic_type() != T_VOID, "need return value of void method?");
366 return t;
367 }
369 // Implementation of Contant
370 intx Constant::hash() const {
371 if (state_before() == NULL) {
372 switch (type()->tag()) {
373 case intTag:
374 return HASH2(name(), type()->as_IntConstant()->value());
375 case addressTag:
376 return HASH2(name(), type()->as_AddressConstant()->value());
377 case longTag:
378 {
379 jlong temp = type()->as_LongConstant()->value();
380 return HASH3(name(), high(temp), low(temp));
381 }
382 case floatTag:
383 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
384 case doubleTag:
385 {
386 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
387 return HASH3(name(), high(temp), low(temp));
388 }
389 case objectTag:
390 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
391 return HASH2(name(), type()->as_ObjectType()->constant_value());
392 case metaDataTag:
393 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
394 return HASH2(name(), type()->as_MetadataType()->constant_value());
395 default:
396 ShouldNotReachHere();
397 }
398 }
399 return 0;
400 }
402 bool Constant::is_equal(Value v) const {
403 if (v->as_Constant() == NULL) return false;
405 switch (type()->tag()) {
406 case intTag:
407 {
408 IntConstant* t1 = type()->as_IntConstant();
409 IntConstant* t2 = v->type()->as_IntConstant();
410 return (t1 != NULL && t2 != NULL &&
411 t1->value() == t2->value());
412 }
413 case longTag:
414 {
415 LongConstant* t1 = type()->as_LongConstant();
416 LongConstant* t2 = v->type()->as_LongConstant();
417 return (t1 != NULL && t2 != NULL &&
418 t1->value() == t2->value());
419 }
420 case floatTag:
421 {
422 FloatConstant* t1 = type()->as_FloatConstant();
423 FloatConstant* t2 = v->type()->as_FloatConstant();
424 return (t1 != NULL && t2 != NULL &&
425 jint_cast(t1->value()) == jint_cast(t2->value()));
426 }
427 case doubleTag:
428 {
429 DoubleConstant* t1 = type()->as_DoubleConstant();
430 DoubleConstant* t2 = v->type()->as_DoubleConstant();
431 return (t1 != NULL && t2 != NULL &&
432 jlong_cast(t1->value()) == jlong_cast(t2->value()));
433 }
434 case objectTag:
435 {
436 ObjectType* t1 = type()->as_ObjectType();
437 ObjectType* t2 = v->type()->as_ObjectType();
438 return (t1 != NULL && t2 != NULL &&
439 t1->is_loaded() && t2->is_loaded() &&
440 t1->constant_value() == t2->constant_value());
441 }
442 case metaDataTag:
443 {
444 MetadataType* t1 = type()->as_MetadataType();
445 MetadataType* t2 = v->type()->as_MetadataType();
446 return (t1 != NULL && t2 != NULL &&
447 t1->is_loaded() && t2->is_loaded() &&
448 t1->constant_value() == t2->constant_value());
449 }
450 }
451 return false;
452 }
454 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
455 Constant* rc = right->as_Constant();
456 // other is not a constant
457 if (rc == NULL) return not_comparable;
459 ValueType* lt = type();
460 ValueType* rt = rc->type();
461 // different types
462 if (lt->base() != rt->base()) return not_comparable;
463 switch (lt->tag()) {
464 case intTag: {
465 int x = lt->as_IntConstant()->value();
466 int y = rt->as_IntConstant()->value();
467 switch (cond) {
468 case If::eql: return x == y ? cond_true : cond_false;
469 case If::neq: return x != y ? cond_true : cond_false;
470 case If::lss: return x < y ? cond_true : cond_false;
471 case If::leq: return x <= y ? cond_true : cond_false;
472 case If::gtr: return x > y ? cond_true : cond_false;
473 case If::geq: return x >= y ? cond_true : cond_false;
474 }
475 break;
476 }
477 case longTag: {
478 jlong x = lt->as_LongConstant()->value();
479 jlong y = rt->as_LongConstant()->value();
480 switch (cond) {
481 case If::eql: return x == y ? cond_true : cond_false;
482 case If::neq: return x != y ? cond_true : cond_false;
483 case If::lss: return x < y ? cond_true : cond_false;
484 case If::leq: return x <= y ? cond_true : cond_false;
485 case If::gtr: return x > y ? cond_true : cond_false;
486 case If::geq: return x >= y ? cond_true : cond_false;
487 }
488 break;
489 }
490 case objectTag: {
491 ciObject* xvalue = lt->as_ObjectType()->constant_value();
492 ciObject* yvalue = rt->as_ObjectType()->constant_value();
493 assert(xvalue != NULL && yvalue != NULL, "not constants");
494 if (xvalue->is_loaded() && yvalue->is_loaded()) {
495 switch (cond) {
496 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
497 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
498 }
499 }
500 break;
501 }
502 case metaDataTag: {
503 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
504 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
505 assert(xvalue != NULL && yvalue != NULL, "not constants");
506 if (xvalue->is_loaded() && yvalue->is_loaded()) {
507 switch (cond) {
508 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
509 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
510 }
511 }
512 break;
513 }
514 }
515 return not_comparable;
516 }
519 // Implementation of BlockBegin
521 void BlockBegin::set_end(BlockEnd* end) {
522 assert(end != NULL, "should not reset block end to NULL");
523 if (end == _end) {
524 return;
525 }
526 clear_end();
528 // Set the new end
529 _end = end;
531 _successors.clear();
532 // Now reset successors list based on BlockEnd
533 for (int i = 0; i < end->number_of_sux(); i++) {
534 BlockBegin* sux = end->sux_at(i);
535 _successors.append(sux);
536 sux->_predecessors.append(this);
537 }
538 _end->set_begin(this);
539 }
542 void BlockBegin::clear_end() {
543 // Must make the predecessors/successors match up with the
544 // BlockEnd's notion.
545 if (_end != NULL) {
546 // disconnect from the old end
547 _end->set_begin(NULL);
549 // disconnect this block from it's current successors
550 for (int i = 0; i < _successors.length(); i++) {
551 _successors.at(i)->remove_predecessor(this);
552 }
553 _end = NULL;
554 }
555 }
558 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
559 // disconnect any edges between from and to
560 #ifndef PRODUCT
561 if (PrintIR && Verbose) {
562 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
563 }
564 #endif
565 for (int s = 0; s < from->number_of_sux();) {
566 BlockBegin* sux = from->sux_at(s);
567 if (sux == to) {
568 int index = sux->_predecessors.index_of(from);
569 if (index >= 0) {
570 sux->_predecessors.remove_at(index);
571 }
572 from->_successors.remove_at(s);
573 } else {
574 s++;
575 }
576 }
577 }
580 void BlockBegin::disconnect_from_graph() {
581 // disconnect this block from all other blocks
582 for (int p = 0; p < number_of_preds(); p++) {
583 pred_at(p)->remove_successor(this);
584 }
585 for (int s = 0; s < number_of_sux(); s++) {
586 sux_at(s)->remove_predecessor(this);
587 }
588 }
590 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
591 // modify predecessors before substituting successors
592 for (int i = 0; i < number_of_sux(); i++) {
593 if (sux_at(i) == old_sux) {
594 // remove old predecessor before adding new predecessor
595 // otherwise there is a dead predecessor in the list
596 new_sux->remove_predecessor(old_sux);
597 new_sux->add_predecessor(this);
598 }
599 }
600 old_sux->remove_predecessor(this);
601 end()->substitute_sux(old_sux, new_sux);
602 }
606 // In general it is not possible to calculate a value for the field "depth_first_number"
607 // of the inserted block, without recomputing the values of the other blocks
608 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
609 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
610 int bci = sux->bci();
611 // critical edge splitting may introduce a goto after a if and array
612 // bound check elimination may insert a predicate between the if and
613 // goto. The bci of the goto can't be the one of the if otherwise
614 // the state and bci are inconsistent and a deoptimization triggered
615 // by the predicate would lead to incorrect execution/a crash.
616 BlockBegin* new_sux = new BlockBegin(bci);
618 // mark this block (special treatment when block order is computed)
619 new_sux->set(critical_edge_split_flag);
621 // This goto is not a safepoint.
622 Goto* e = new Goto(sux, false);
623 new_sux->set_next(e, bci);
624 new_sux->set_end(e);
625 // setup states
626 ValueStack* s = end()->state();
627 new_sux->set_state(s->copy(s->kind(), bci));
628 e->set_state(s->copy(s->kind(), bci));
629 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
630 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
631 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
633 // link predecessor to new block
634 end()->substitute_sux(sux, new_sux);
636 // The ordering needs to be the same, so remove the link that the
637 // set_end call above added and substitute the new_sux for this
638 // block.
639 sux->remove_predecessor(new_sux);
641 // the successor could be the target of a switch so it might have
642 // multiple copies of this predecessor, so substitute the new_sux
643 // for the first and delete the rest.
644 bool assigned = false;
645 BlockList& list = sux->_predecessors;
646 for (int i = 0; i < list.length(); i++) {
647 BlockBegin** b = list.adr_at(i);
648 if (*b == this) {
649 if (assigned) {
650 list.remove_at(i);
651 // reprocess this index
652 i--;
653 } else {
654 assigned = true;
655 *b = new_sux;
656 }
657 // link the new block back to it's predecessors.
658 new_sux->add_predecessor(this);
659 }
660 }
661 assert(assigned == true, "should have assigned at least once");
662 return new_sux;
663 }
666 void BlockBegin::remove_successor(BlockBegin* pred) {
667 int idx;
668 while ((idx = _successors.index_of(pred)) >= 0) {
669 _successors.remove_at(idx);
670 }
671 }
674 void BlockBegin::add_predecessor(BlockBegin* pred) {
675 _predecessors.append(pred);
676 }
679 void BlockBegin::remove_predecessor(BlockBegin* pred) {
680 int idx;
681 while ((idx = _predecessors.index_of(pred)) >= 0) {
682 _predecessors.remove_at(idx);
683 }
684 }
687 void BlockBegin::add_exception_handler(BlockBegin* b) {
688 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
689 // add only if not in the list already
690 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
691 }
693 int BlockBegin::add_exception_state(ValueStack* state) {
694 assert(is_set(exception_entry_flag), "only for xhandlers");
695 if (_exception_states == NULL) {
696 _exception_states = new ValueStackStack(4);
697 }
698 _exception_states->append(state);
699 return _exception_states->length() - 1;
700 }
703 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
704 if (!mark.at(block_id())) {
705 mark.at_put(block_id(), true);
706 closure->block_do(this);
707 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
708 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
709 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
710 }
711 }
714 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
715 if (!mark.at(block_id())) {
716 mark.at_put(block_id(), true);
717 BlockEnd* e = end();
718 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
719 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
720 closure->block_do(this);
721 }
722 }
725 void BlockBegin::iterate_preorder(BlockClosure* closure) {
726 boolArray mark(number_of_blocks(), false);
727 iterate_preorder(mark, closure);
728 }
731 void BlockBegin::iterate_postorder(BlockClosure* closure) {
732 boolArray mark(number_of_blocks(), false);
733 iterate_postorder(mark, closure);
734 }
737 void BlockBegin::block_values_do(ValueVisitor* f) {
738 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
739 }
742 #ifndef PRODUCT
743 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
744 #else
745 #define TRACE_PHI(coce)
746 #endif
749 bool BlockBegin::try_merge(ValueStack* new_state) {
750 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
752 // local variables used for state iteration
753 int index;
754 Value new_value, existing_value;
756 ValueStack* existing_state = state();
757 if (existing_state == NULL) {
758 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
760 if (is_set(BlockBegin::was_visited_flag)) {
761 // this actually happens for complicated jsr/ret structures
762 return false; // BAILOUT in caller
763 }
765 // copy state because it is altered
766 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
768 // Use method liveness to invalidate dead locals
769 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
770 if (liveness.is_valid()) {
771 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
773 for_each_local_value(new_state, index, new_value) {
774 if (!liveness.at(index) || new_value->type()->is_illegal()) {
775 new_state->invalidate_local(index);
776 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
777 }
778 }
779 }
781 if (is_set(BlockBegin::parser_loop_header_flag)) {
782 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
784 for_each_stack_value(new_state, index, new_value) {
785 new_state->setup_phi_for_stack(this, index);
786 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));
787 }
789 BitMap requires_phi_function = new_state->scope()->requires_phi_function();
791 for_each_local_value(new_state, index, new_value) {
792 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
793 if (requires_phi || !SelectivePhiFunctions) {
794 new_state->setup_phi_for_local(this, index);
795 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));
796 }
797 }
798 }
800 // initialize state of block
801 set_state(new_state);
803 } else if (existing_state->is_same(new_state)) {
804 TRACE_PHI(tty->print_cr("exisiting state found"));
806 assert(existing_state->scope() == new_state->scope(), "not matching");
807 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
808 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
810 if (is_set(BlockBegin::was_visited_flag)) {
811 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
813 if (!is_set(BlockBegin::parser_loop_header_flag)) {
814 // this actually happens for complicated jsr/ret structures
815 return false; // BAILOUT in caller
816 }
818 for_each_local_value(existing_state, index, existing_value) {
819 Value new_value = new_state->local_at(index);
820 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
821 // The old code invalidated the phi function here
822 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
823 return false; // BAILOUT in caller
824 }
825 }
827 #ifdef ASSERT
828 // check that all necessary phi functions are present
829 for_each_stack_value(existing_state, index, existing_value) {
830 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
831 }
832 for_each_local_value(existing_state, index, existing_value) {
833 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
834 }
835 #endif
837 } else {
838 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
840 // create necessary phi functions for stack
841 for_each_stack_value(existing_state, index, existing_value) {
842 Value new_value = new_state->stack_at(index);
843 Phi* existing_phi = existing_value->as_Phi();
845 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
846 existing_state->setup_phi_for_stack(this, index);
847 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));
848 }
849 }
851 // create necessary phi functions for locals
852 for_each_local_value(existing_state, index, existing_value) {
853 Value new_value = new_state->local_at(index);
854 Phi* existing_phi = existing_value->as_Phi();
856 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
857 existing_state->invalidate_local(index);
858 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
859 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
860 existing_state->setup_phi_for_local(this, index);
861 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));
862 }
863 }
864 }
866 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
868 } else {
869 assert(false, "stack or locks not matching (invalid bytecodes)");
870 return false;
871 }
873 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
875 return true;
876 }
879 #ifndef PRODUCT
880 void BlockBegin::print_block() {
881 InstructionPrinter ip;
882 print_block(ip, false);
883 }
886 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
887 ip.print_instr(this); tty->cr();
888 ip.print_stack(this->state()); tty->cr();
889 ip.print_inline_level(this);
890 ip.print_head();
891 for (Instruction* n = next(); n != NULL; n = n->next()) {
892 if (!live_only || n->is_pinned() || n->use_count() > 0) {
893 ip.print_line(n);
894 }
895 }
896 tty->cr();
897 }
898 #endif // PRODUCT
901 // Implementation of BlockList
903 void BlockList::iterate_forward (BlockClosure* closure) {
904 const int l = length();
905 for (int i = 0; i < l; i++) closure->block_do(at(i));
906 }
909 void BlockList::iterate_backward(BlockClosure* closure) {
910 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
911 }
914 void BlockList::blocks_do(void f(BlockBegin*)) {
915 for (int i = length() - 1; i >= 0; i--) f(at(i));
916 }
919 void BlockList::values_do(ValueVisitor* f) {
920 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
921 }
924 #ifndef PRODUCT
925 void BlockList::print(bool cfg_only, bool live_only) {
926 InstructionPrinter ip;
927 for (int i = 0; i < length(); i++) {
928 BlockBegin* block = at(i);
929 if (cfg_only) {
930 ip.print_instr(block); tty->cr();
931 } else {
932 block->print_block(ip, live_only);
933 }
934 }
935 }
936 #endif // PRODUCT
939 // Implementation of BlockEnd
941 void BlockEnd::set_begin(BlockBegin* begin) {
942 BlockList* sux = NULL;
943 if (begin != NULL) {
944 sux = begin->successors();
945 } else if (this->begin() != NULL) {
946 // copy our sux list
947 BlockList* sux = new BlockList(this->begin()->number_of_sux());
948 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
949 sux->append(this->begin()->sux_at(i));
950 }
951 }
952 _sux = sux;
953 }
956 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
957 substitute(*_sux, old_sux, new_sux);
958 }
961 // Implementation of Phi
963 // Normal phi functions take their operands from the last instruction of the
964 // predecessor. Special handling is needed for xhanlder entries because there
965 // the state of arbitrary instructions are needed.
967 Value Phi::operand_at(int i) const {
968 ValueStack* state;
969 if (_block->is_set(BlockBegin::exception_entry_flag)) {
970 state = _block->exception_state_at(i);
971 } else {
972 state = _block->pred_at(i)->end()->state();
973 }
974 assert(state != NULL, "");
976 if (is_local()) {
977 return state->local_at(local_index());
978 } else {
979 return state->stack_at(stack_index());
980 }
981 }
984 int Phi::operand_count() const {
985 if (_block->is_set(BlockBegin::exception_entry_flag)) {
986 return _block->number_of_exception_states();
987 } else {
988 return _block->number_of_preds();
989 }
990 }
992 #ifdef ASSERT
993 // Constructor of Assert
994 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
995 , _x(x)
996 , _cond(cond)
997 , _y(y)
998 {
999 set_flag(UnorderedIsTrueFlag, unordered_is_true);
1000 assert(x->type()->tag() == y->type()->tag(), "types must match");
1001 pin();
1003 stringStream strStream;
1004 Compilation::current()->method()->print_name(&strStream);
1006 stringStream strStream1;
1007 InstructionPrinter ip1(1, &strStream1);
1008 ip1.print_instr(x);
1010 stringStream strStream2;
1011 InstructionPrinter ip2(1, &strStream2);
1012 ip2.print_instr(y);
1014 stringStream ss;
1015 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1017 _message = ss.as_string();
1018 }
1019 #endif
1021 void RangeCheckPredicate::check_state() {
1022 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1023 }
1025 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1026 if (state() != NULL) state()->values_do(f);
1027 }
