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src/share/vm/c1/c1_Instruction.cpp@710a3c8b516e
src/share/vm/c1/c1_Instruction.cpp
Tue, 08 Aug 2017 15:57:29 +0800
- author
- aoqi
- date
- Tue, 08 Aug 2017 15:57:29 +0800
- changeset 6876
- 710a3c8b516e
- parent 6198
- 55fb97c4c58d
- parent 0
- f90c822e73f8
- child 8856
- ac27a9c85bea
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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 ciType *t = _target->signature()->return_type();
364 assert(t->basic_type() != T_VOID, "need return value of void method?");
365 return t;
366 }
368 // Implementation of Contant
369 intx Constant::hash() const {
370 if (state_before() == NULL) {
371 switch (type()->tag()) {
372 case intTag:
373 return HASH2(name(), type()->as_IntConstant()->value());
374 case addressTag:
375 return HASH2(name(), type()->as_AddressConstant()->value());
376 case longTag:
377 {
378 jlong temp = type()->as_LongConstant()->value();
379 return HASH3(name(), high(temp), low(temp));
380 }
381 case floatTag:
382 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
383 case doubleTag:
384 {
385 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
386 return HASH3(name(), high(temp), low(temp));
387 }
388 case objectTag:
389 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
390 return HASH2(name(), type()->as_ObjectType()->constant_value());
391 case metaDataTag:
392 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
393 return HASH2(name(), type()->as_MetadataType()->constant_value());
394 default:
395 ShouldNotReachHere();
396 }
397 }
398 return 0;
399 }
401 bool Constant::is_equal(Value v) const {
402 if (v->as_Constant() == NULL) return false;
404 switch (type()->tag()) {
405 case intTag:
406 {
407 IntConstant* t1 = type()->as_IntConstant();
408 IntConstant* t2 = v->type()->as_IntConstant();
409 return (t1 != NULL && t2 != NULL &&
410 t1->value() == t2->value());
411 }
412 case longTag:
413 {
414 LongConstant* t1 = type()->as_LongConstant();
415 LongConstant* t2 = v->type()->as_LongConstant();
416 return (t1 != NULL && t2 != NULL &&
417 t1->value() == t2->value());
418 }
419 case floatTag:
420 {
421 FloatConstant* t1 = type()->as_FloatConstant();
422 FloatConstant* t2 = v->type()->as_FloatConstant();
423 return (t1 != NULL && t2 != NULL &&
424 jint_cast(t1->value()) == jint_cast(t2->value()));
425 }
426 case doubleTag:
427 {
428 DoubleConstant* t1 = type()->as_DoubleConstant();
429 DoubleConstant* t2 = v->type()->as_DoubleConstant();
430 return (t1 != NULL && t2 != NULL &&
431 jlong_cast(t1->value()) == jlong_cast(t2->value()));
432 }
433 case objectTag:
434 {
435 ObjectType* t1 = type()->as_ObjectType();
436 ObjectType* t2 = v->type()->as_ObjectType();
437 return (t1 != NULL && t2 != NULL &&
438 t1->is_loaded() && t2->is_loaded() &&
439 t1->constant_value() == t2->constant_value());
440 }
441 case metaDataTag:
442 {
443 MetadataType* t1 = type()->as_MetadataType();
444 MetadataType* t2 = v->type()->as_MetadataType();
445 return (t1 != NULL && t2 != NULL &&
446 t1->is_loaded() && t2->is_loaded() &&
447 t1->constant_value() == t2->constant_value());
448 }
449 }
450 return false;
451 }
453 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
454 Constant* rc = right->as_Constant();
455 // other is not a constant
456 if (rc == NULL) return not_comparable;
458 ValueType* lt = type();
459 ValueType* rt = rc->type();
460 // different types
461 if (lt->base() != rt->base()) return not_comparable;
462 switch (lt->tag()) {
463 case intTag: {
464 int x = lt->as_IntConstant()->value();
465 int y = rt->as_IntConstant()->value();
466 switch (cond) {
467 case If::eql: return x == y ? cond_true : cond_false;
468 case If::neq: return x != y ? cond_true : cond_false;
469 case If::lss: return x < y ? cond_true : cond_false;
470 case If::leq: return x <= y ? cond_true : cond_false;
471 case If::gtr: return x > y ? cond_true : cond_false;
472 case If::geq: return x >= y ? cond_true : cond_false;
473 }
474 break;
475 }
476 case longTag: {
477 jlong x = lt->as_LongConstant()->value();
478 jlong y = rt->as_LongConstant()->value();
479 switch (cond) {
480 case If::eql: return x == y ? cond_true : cond_false;
481 case If::neq: return x != y ? cond_true : cond_false;
482 case If::lss: return x < y ? cond_true : cond_false;
483 case If::leq: return x <= y ? cond_true : cond_false;
484 case If::gtr: return x > y ? cond_true : cond_false;
485 case If::geq: return x >= y ? cond_true : cond_false;
486 }
487 break;
488 }
489 case objectTag: {
490 ciObject* xvalue = lt->as_ObjectType()->constant_value();
491 ciObject* yvalue = rt->as_ObjectType()->constant_value();
492 assert(xvalue != NULL && yvalue != NULL, "not constants");
493 if (xvalue->is_loaded() && yvalue->is_loaded()) {
494 switch (cond) {
495 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
496 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
497 }
498 }
499 break;
500 }
501 case metaDataTag: {
502 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
503 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
504 assert(xvalue != NULL && yvalue != NULL, "not constants");
505 if (xvalue->is_loaded() && yvalue->is_loaded()) {
506 switch (cond) {
507 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
508 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
509 }
510 }
511 break;
512 }
513 }
514 return not_comparable;
515 }
518 // Implementation of BlockBegin
520 void BlockBegin::set_end(BlockEnd* end) {
521 assert(end != NULL, "should not reset block end to NULL");
522 if (end == _end) {
523 return;
524 }
525 clear_end();
527 // Set the new end
528 _end = end;
530 _successors.clear();
531 // Now reset successors list based on BlockEnd
532 for (int i = 0; i < end->number_of_sux(); i++) {
533 BlockBegin* sux = end->sux_at(i);
534 _successors.append(sux);
535 sux->_predecessors.append(this);
536 }
537 _end->set_begin(this);
538 }
541 void BlockBegin::clear_end() {
542 // Must make the predecessors/successors match up with the
543 // BlockEnd's notion.
544 if (_end != NULL) {
545 // disconnect from the old end
546 _end->set_begin(NULL);
548 // disconnect this block from it's current successors
549 for (int i = 0; i < _successors.length(); i++) {
550 _successors.at(i)->remove_predecessor(this);
551 }
552 _end = NULL;
553 }
554 }
557 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
558 // disconnect any edges between from and to
559 #ifndef PRODUCT
560 if (PrintIR && Verbose) {
561 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
562 }
563 #endif
564 for (int s = 0; s < from->number_of_sux();) {
565 BlockBegin* sux = from->sux_at(s);
566 if (sux == to) {
567 int index = sux->_predecessors.index_of(from);
568 if (index >= 0) {
569 sux->_predecessors.remove_at(index);
570 }
571 from->_successors.remove_at(s);
572 } else {
573 s++;
574 }
575 }
576 }
579 void BlockBegin::disconnect_from_graph() {
580 // disconnect this block from all other blocks
581 for (int p = 0; p < number_of_preds(); p++) {
582 pred_at(p)->remove_successor(this);
583 }
584 for (int s = 0; s < number_of_sux(); s++) {
585 sux_at(s)->remove_predecessor(this);
586 }
587 }
589 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
590 // modify predecessors before substituting successors
591 for (int i = 0; i < number_of_sux(); i++) {
592 if (sux_at(i) == old_sux) {
593 // remove old predecessor before adding new predecessor
594 // otherwise there is a dead predecessor in the list
595 new_sux->remove_predecessor(old_sux);
596 new_sux->add_predecessor(this);
597 }
598 }
599 old_sux->remove_predecessor(this);
600 end()->substitute_sux(old_sux, new_sux);
601 }
605 // In general it is not possible to calculate a value for the field "depth_first_number"
606 // of the inserted block, without recomputing the values of the other blocks
607 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
608 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
609 int bci = sux->bci();
610 // critical edge splitting may introduce a goto after a if and array
611 // bound check elimination may insert a predicate between the if and
612 // goto. The bci of the goto can't be the one of the if otherwise
613 // the state and bci are inconsistent and a deoptimization triggered
614 // by the predicate would lead to incorrect execution/a crash.
615 BlockBegin* new_sux = new BlockBegin(bci);
617 // mark this block (special treatment when block order is computed)
618 new_sux->set(critical_edge_split_flag);
620 // This goto is not a safepoint.
621 Goto* e = new Goto(sux, false);
622 new_sux->set_next(e, bci);
623 new_sux->set_end(e);
624 // setup states
625 ValueStack* s = end()->state();
626 new_sux->set_state(s->copy(s->kind(), bci));
627 e->set_state(s->copy(s->kind(), bci));
628 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
629 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
630 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
632 // link predecessor to new block
633 end()->substitute_sux(sux, new_sux);
635 // The ordering needs to be the same, so remove the link that the
636 // set_end call above added and substitute the new_sux for this
637 // block.
638 sux->remove_predecessor(new_sux);
640 // the successor could be the target of a switch so it might have
641 // multiple copies of this predecessor, so substitute the new_sux
642 // for the first and delete the rest.
643 bool assigned = false;
644 BlockList& list = sux->_predecessors;
645 for (int i = 0; i < list.length(); i++) {
646 BlockBegin** b = list.adr_at(i);
647 if (*b == this) {
648 if (assigned) {
649 list.remove_at(i);
650 // reprocess this index
651 i--;
652 } else {
653 assigned = true;
654 *b = new_sux;
655 }
656 // link the new block back to it's predecessors.
657 new_sux->add_predecessor(this);
658 }
659 }
660 assert(assigned == true, "should have assigned at least once");
661 return new_sux;
662 }
665 void BlockBegin::remove_successor(BlockBegin* pred) {
666 int idx;
667 while ((idx = _successors.index_of(pred)) >= 0) {
668 _successors.remove_at(idx);
669 }
670 }
673 void BlockBegin::add_predecessor(BlockBegin* pred) {
674 _predecessors.append(pred);
675 }
678 void BlockBegin::remove_predecessor(BlockBegin* pred) {
679 int idx;
680 while ((idx = _predecessors.index_of(pred)) >= 0) {
681 _predecessors.remove_at(idx);
682 }
683 }
686 void BlockBegin::add_exception_handler(BlockBegin* b) {
687 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
688 // add only if not in the list already
689 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
690 }
692 int BlockBegin::add_exception_state(ValueStack* state) {
693 assert(is_set(exception_entry_flag), "only for xhandlers");
694 if (_exception_states == NULL) {
695 _exception_states = new ValueStackStack(4);
696 }
697 _exception_states->append(state);
698 return _exception_states->length() - 1;
699 }
702 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
703 if (!mark.at(block_id())) {
704 mark.at_put(block_id(), true);
705 closure->block_do(this);
706 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
707 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
708 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
709 }
710 }
713 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
714 if (!mark.at(block_id())) {
715 mark.at_put(block_id(), true);
716 BlockEnd* e = end();
717 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
718 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
719 closure->block_do(this);
720 }
721 }
724 void BlockBegin::iterate_preorder(BlockClosure* closure) {
725 boolArray mark(number_of_blocks(), false);
726 iterate_preorder(mark, closure);
727 }
730 void BlockBegin::iterate_postorder(BlockClosure* closure) {
731 boolArray mark(number_of_blocks(), false);
732 iterate_postorder(mark, closure);
733 }
736 void BlockBegin::block_values_do(ValueVisitor* f) {
737 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
738 }
741 #ifndef PRODUCT
742 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
743 #else
744 #define TRACE_PHI(coce)
745 #endif
748 bool BlockBegin::try_merge(ValueStack* new_state) {
749 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
751 // local variables used for state iteration
752 int index;
753 Value new_value, existing_value;
755 ValueStack* existing_state = state();
756 if (existing_state == NULL) {
757 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
759 if (is_set(BlockBegin::was_visited_flag)) {
760 // this actually happens for complicated jsr/ret structures
761 return false; // BAILOUT in caller
762 }
764 // copy state because it is altered
765 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
767 // Use method liveness to invalidate dead locals
768 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
769 if (liveness.is_valid()) {
770 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
772 for_each_local_value(new_state, index, new_value) {
773 if (!liveness.at(index) || new_value->type()->is_illegal()) {
774 new_state->invalidate_local(index);
775 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
776 }
777 }
778 }
780 if (is_set(BlockBegin::parser_loop_header_flag)) {
781 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
783 for_each_stack_value(new_state, index, new_value) {
784 new_state->setup_phi_for_stack(this, index);
785 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));
786 }
788 BitMap requires_phi_function = new_state->scope()->requires_phi_function();
790 for_each_local_value(new_state, index, new_value) {
791 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
792 if (requires_phi || !SelectivePhiFunctions) {
793 new_state->setup_phi_for_local(this, index);
794 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));
795 }
796 }
797 }
799 // initialize state of block
800 set_state(new_state);
802 } else if (existing_state->is_same(new_state)) {
803 TRACE_PHI(tty->print_cr("exisiting state found"));
805 assert(existing_state->scope() == new_state->scope(), "not matching");
806 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
807 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
809 if (is_set(BlockBegin::was_visited_flag)) {
810 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
812 if (!is_set(BlockBegin::parser_loop_header_flag)) {
813 // this actually happens for complicated jsr/ret structures
814 return false; // BAILOUT in caller
815 }
817 for_each_local_value(existing_state, index, existing_value) {
818 Value new_value = new_state->local_at(index);
819 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
820 // The old code invalidated the phi function here
821 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
822 return false; // BAILOUT in caller
823 }
824 }
826 #ifdef ASSERT
827 // check that all necessary phi functions are present
828 for_each_stack_value(existing_state, index, existing_value) {
829 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
830 }
831 for_each_local_value(existing_state, index, existing_value) {
832 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
833 }
834 #endif
836 } else {
837 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
839 // create necessary phi functions for stack
840 for_each_stack_value(existing_state, index, existing_value) {
841 Value new_value = new_state->stack_at(index);
842 Phi* existing_phi = existing_value->as_Phi();
844 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
845 existing_state->setup_phi_for_stack(this, index);
846 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));
847 }
848 }
850 // create necessary phi functions for locals
851 for_each_local_value(existing_state, index, existing_value) {
852 Value new_value = new_state->local_at(index);
853 Phi* existing_phi = existing_value->as_Phi();
855 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
856 existing_state->invalidate_local(index);
857 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
858 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
859 existing_state->setup_phi_for_local(this, index);
860 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));
861 }
862 }
863 }
865 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
867 } else {
868 assert(false, "stack or locks not matching (invalid bytecodes)");
869 return false;
870 }
872 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
874 return true;
875 }
878 #ifndef PRODUCT
879 void BlockBegin::print_block() {
880 InstructionPrinter ip;
881 print_block(ip, false);
882 }
885 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
886 ip.print_instr(this); tty->cr();
887 ip.print_stack(this->state()); tty->cr();
888 ip.print_inline_level(this);
889 ip.print_head();
890 for (Instruction* n = next(); n != NULL; n = n->next()) {
891 if (!live_only || n->is_pinned() || n->use_count() > 0) {
892 ip.print_line(n);
893 }
894 }
895 tty->cr();
896 }
897 #endif // PRODUCT
900 // Implementation of BlockList
902 void BlockList::iterate_forward (BlockClosure* closure) {
903 const int l = length();
904 for (int i = 0; i < l; i++) closure->block_do(at(i));
905 }
908 void BlockList::iterate_backward(BlockClosure* closure) {
909 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
910 }
913 void BlockList::blocks_do(void f(BlockBegin*)) {
914 for (int i = length() - 1; i >= 0; i--) f(at(i));
915 }
918 void BlockList::values_do(ValueVisitor* f) {
919 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
920 }
923 #ifndef PRODUCT
924 void BlockList::print(bool cfg_only, bool live_only) {
925 InstructionPrinter ip;
926 for (int i = 0; i < length(); i++) {
927 BlockBegin* block = at(i);
928 if (cfg_only) {
929 ip.print_instr(block); tty->cr();
930 } else {
931 block->print_block(ip, live_only);
932 }
933 }
934 }
935 #endif // PRODUCT
938 // Implementation of BlockEnd
940 void BlockEnd::set_begin(BlockBegin* begin) {
941 BlockList* sux = NULL;
942 if (begin != NULL) {
943 sux = begin->successors();
944 } else if (this->begin() != NULL) {
945 // copy our sux list
946 BlockList* sux = new BlockList(this->begin()->number_of_sux());
947 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
948 sux->append(this->begin()->sux_at(i));
949 }
950 }
951 _sux = sux;
952 }
955 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
956 substitute(*_sux, old_sux, new_sux);
957 }
960 // Implementation of Phi
962 // Normal phi functions take their operands from the last instruction of the
963 // predecessor. Special handling is needed for xhanlder entries because there
964 // the state of arbitrary instructions are needed.
966 Value Phi::operand_at(int i) const {
967 ValueStack* state;
968 if (_block->is_set(BlockBegin::exception_entry_flag)) {
969 state = _block->exception_state_at(i);
970 } else {
971 state = _block->pred_at(i)->end()->state();
972 }
973 assert(state != NULL, "");
975 if (is_local()) {
976 return state->local_at(local_index());
977 } else {
978 return state->stack_at(stack_index());
979 }
980 }
983 int Phi::operand_count() const {
984 if (_block->is_set(BlockBegin::exception_entry_flag)) {
985 return _block->number_of_exception_states();
986 } else {
987 return _block->number_of_preds();
988 }
989 }
991 #ifdef ASSERT
992 // Constructor of Assert
993 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
994 , _x(x)
995 , _cond(cond)
996 , _y(y)
997 {
998 set_flag(UnorderedIsTrueFlag, unordered_is_true);
999 assert(x->type()->tag() == y->type()->tag(), "types must match");
1000 pin();
1002 stringStream strStream;
1003 Compilation::current()->method()->print_name(&strStream);
1005 stringStream strStream1;
1006 InstructionPrinter ip1(1, &strStream1);
1007 ip1.print_instr(x);
1009 stringStream strStream2;
1010 InstructionPrinter ip2(1, &strStream2);
1011 ip2.print_instr(y);
1013 stringStream ss;
1014 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1016 _message = ss.as_string();
1017 }
1018 #endif
1020 void RangeCheckPredicate::check_state() {
1021 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1022 }
1024 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1025 if (state() != NULL) state()->values_do(f);
1026 }
