1 /*
2 * Copyright (c) 1999, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "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"
32 #include "ci/ciValueArrayKlass.hpp"
33 #include "ci/ciValueKlass.hpp"
34
35
36 // Implementation of Instruction
37
38
39 int Instruction::dominator_depth() {
40 int result = -1;
41 if (block()) {
42 result = block()->dominator_depth();
43 }
44 assert(result != -1 || this->as_Local(), "Only locals have dominator depth -1");
45 return result;
46 }
47
48 Instruction::Condition Instruction::mirror(Condition cond) {
49 switch (cond) {
50 case eql: return eql;
51 case neq: return neq;
52 case lss: return gtr;
53 case leq: return geq;
54 case gtr: return lss;
55 case geq: return leq;
56 case aeq: return beq;
57 case beq: return aeq;
58 }
59 ShouldNotReachHere();
60 return eql;
61 }
62
63
64 Instruction::Condition Instruction::negate(Condition cond) {
65 switch (cond) {
66 case eql: return neq;
67 case neq: return eql;
68 case lss: return geq;
69 case leq: return gtr;
70 case gtr: return leq;
71 case geq: return lss;
72 case aeq: assert(false, "Above equal cannot be negated");
73 case beq: assert(false, "Below equal cannot be negated");
74 }
75 ShouldNotReachHere();
76 return eql;
77 }
78
79 void Instruction::update_exception_state(ValueStack* state) {
80 if (state != NULL && (state->kind() == ValueStack::EmptyExceptionState || state->kind() == ValueStack::ExceptionState)) {
81 assert(state->kind() == ValueStack::EmptyExceptionState || Compilation::current()->env()->should_retain_local_variables(), "unexpected state kind");
82 _exception_state = state;
83 } else {
84 _exception_state = NULL;
85 }
86 }
87
88 // Prev without need to have BlockBegin
89 Instruction* Instruction::prev() {
90 Instruction* p = NULL;
91 Instruction* q = block();
92 while (q != this) {
93 assert(q != NULL, "this is not in the block's instruction list");
94 p = q; q = q->next();
95 }
96 return p;
97 }
98
99
100 void Instruction::state_values_do(ValueVisitor* f) {
101 if (state_before() != NULL) {
102 state_before()->values_do(f);
103 }
104 if (exception_state() != NULL){
105 exception_state()->values_do(f);
106 }
107 }
108
109 ciType* Instruction::exact_type() const {
110 ciType* t = declared_type();
111 if (t != NULL && t->is_klass()) {
112 return t->as_klass()->exact_klass();
113 }
114 return NULL;
115 }
116
117 bool Instruction::is_flattened_array() const {
118 if (ValueArrayFlatten) {
119 ciType* type = declared_type();
120 if (type != NULL &&
121 type->is_value_array_klass() &&
122 type->as_value_array_klass()->element_klass()->as_value_klass()->flatten_array()) {
123 return true;
124 }
125 }
126
127 return false;
128 }
129
130 #ifndef PRODUCT
131 void Instruction::check_state(ValueStack* state) {
132 if (state != NULL) {
133 state->verify();
134 }
135 }
136
137
138 void Instruction::print() {
139 InstructionPrinter ip;
140 print(ip);
141 }
142
143
144 void Instruction::print_line() {
145 InstructionPrinter ip;
146 ip.print_line(this);
147 }
148
149
150 void Instruction::print(InstructionPrinter& ip) {
151 ip.print_head();
152 ip.print_line(this);
153 tty->cr();
154 }
155 #endif // PRODUCT
156
157
158 // perform constant and interval tests on index value
159 bool AccessIndexed::compute_needs_range_check() {
160 if (length()) {
161 Constant* clength = length()->as_Constant();
162 Constant* cindex = index()->as_Constant();
163 if (clength && cindex) {
164 IntConstant* l = clength->type()->as_IntConstant();
165 IntConstant* i = cindex->type()->as_IntConstant();
166 if (l && i && i->value() < l->value() && i->value() >= 0) {
167 return false;
168 }
169 }
170 }
171
172 if (!this->check_flag(NeedsRangeCheckFlag)) {
173 return false;
174 }
175
176 return true;
177 }
178
179
180 ciType* Constant::exact_type() const {
181 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) {
182 return type()->as_ObjectType()->exact_type();
183 }
184 return NULL;
185 }
186
187 ciType* LoadIndexed::exact_type() const {
188 ciType* array_type = array()->exact_type();
189 if (array_type != NULL) {
190 assert(array_type->is_array_klass(), "what else?");
191 ciArrayKlass* ak = (ciArrayKlass*)array_type;
192
193 if (ak->element_type()->is_instance_klass()) {
194 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
195 if (ik->is_loaded() && ik->is_final()) {
196 return ik;
197 }
198 }
199 }
200 return Instruction::exact_type();
201 }
202
203
204 ciType* LoadIndexed::declared_type() const {
205 ciType* array_type = array()->declared_type();
206 if (array_type == NULL || !array_type->is_loaded()) {
207 return NULL;
208 }
209 assert(array_type->is_array_klass(), "what else?");
210 ciArrayKlass* ak = (ciArrayKlass*)array_type;
211 return ak->element_type();
212 }
213
214
215 ciType* LoadField::declared_type() const {
216 return field()->type();
217 }
218
219
220 ciType* NewTypeArray::exact_type() const {
221 return ciTypeArrayKlass::make(elt_type());
222 }
223
224 ciType* NewObjectArray::exact_type() const {
225 ciKlass* element_klass = klass();
226 if (element_klass->is_valuetype()) {
227 return ciValueArrayKlass::make(element_klass);
228 } else {
229 return ciObjArrayKlass::make(element_klass);
230 }
231 }
232
233 ciType* NewArray::declared_type() const {
234 return exact_type();
235 }
236
237 ciType* NewInstance::exact_type() const {
238 return klass();
239 }
240
241 ciType* NewInstance::declared_type() const {
242 return exact_type();
243 }
244
245 Value NewValueTypeInstance::depends_on() {
246 if (_depends_on != this) {
247 if (_depends_on->as_NewValueTypeInstance() != NULL) {
248 return _depends_on->as_NewValueTypeInstance()->depends_on();
249 }
250 }
251 return _depends_on;
252 }
253
254 ciType* NewValueTypeInstance::exact_type() const {
255 return klass();
256 }
257
258 ciType* NewValueTypeInstance::declared_type() const {
259 return exact_type();
260 }
261
262 ciType* CheckCast::declared_type() const {
263 return klass();
264 }
265
266 // Implementation of ArithmeticOp
267
268 bool ArithmeticOp::is_commutative() const {
269 switch (op()) {
270 case Bytecodes::_iadd: // fall through
271 case Bytecodes::_ladd: // fall through
272 case Bytecodes::_fadd: // fall through
273 case Bytecodes::_dadd: // fall through
274 case Bytecodes::_imul: // fall through
275 case Bytecodes::_lmul: // fall through
276 case Bytecodes::_fmul: // fall through
277 case Bytecodes::_dmul: return true;
278 default : return false;
279 }
280 }
281
282
283 bool ArithmeticOp::can_trap() const {
284 switch (op()) {
285 case Bytecodes::_idiv: // fall through
286 case Bytecodes::_ldiv: // fall through
287 case Bytecodes::_irem: // fall through
288 case Bytecodes::_lrem: return true;
289 default : return false;
290 }
291 }
292
293
294 // Implementation of LogicOp
295
296 bool LogicOp::is_commutative() const {
297 #ifdef ASSERT
298 switch (op()) {
299 case Bytecodes::_iand: // fall through
300 case Bytecodes::_land: // fall through
301 case Bytecodes::_ior : // fall through
302 case Bytecodes::_lor : // fall through
303 case Bytecodes::_ixor: // fall through
304 case Bytecodes::_lxor: break;
305 default : ShouldNotReachHere(); break;
306 }
307 #endif
308 // all LogicOps are commutative
309 return true;
310 }
311
312
313 // Implementation of IfOp
314
315 bool IfOp::is_commutative() const {
316 return cond() == eql || cond() == neq;
317 }
318
319
320 // Implementation of StateSplit
321
322 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
323 NOT_PRODUCT(bool assigned = false;)
324 for (int i = 0; i < list.length(); i++) {
325 BlockBegin** b = list.adr_at(i);
326 if (*b == old_block) {
327 *b = new_block;
328 NOT_PRODUCT(assigned = true;)
329 }
330 }
331 assert(assigned == true, "should have assigned at least once");
332 }
333
334
335 IRScope* StateSplit::scope() const {
336 return _state->scope();
337 }
338
339
340 void StateSplit::state_values_do(ValueVisitor* f) {
341 Instruction::state_values_do(f);
342 if (state() != NULL) state()->values_do(f);
343 }
344
345
346 void BlockBegin::state_values_do(ValueVisitor* f) {
347 StateSplit::state_values_do(f);
348
349 if (is_set(BlockBegin::exception_entry_flag)) {
350 for (int i = 0; i < number_of_exception_states(); i++) {
351 exception_state_at(i)->values_do(f);
352 }
353 }
354 }
355
356
357 // Implementation of Invoke
358
359
360 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
361 int vtable_index, ciMethod* target, ValueStack* state_before)
362 : StateSplit(result_type, state_before)
363 , _code(code)
364 , _recv(recv)
365 , _args(args)
366 , _vtable_index(vtable_index)
367 , _target(target)
368 {
369 set_flag(TargetIsLoadedFlag, target->is_loaded());
370 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
371 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
372
373 assert(args != NULL, "args must exist");
374 #ifdef ASSERT
375 AssertValues assert_value;
376 values_do(&assert_value);
377 #endif
378
379 // provide an initial guess of signature size.
380 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
381 if (has_receiver()) {
382 _signature->append(as_BasicType(receiver()->type()));
383 }
384 for (int i = 0; i < number_of_arguments(); i++) {
385 ValueType* t = argument_at(i)->type();
386 BasicType bt = as_BasicType(t);
387 _signature->append(bt);
388 }
389 }
390
391
392 void Invoke::state_values_do(ValueVisitor* f) {
393 StateSplit::state_values_do(f);
394 if (state_before() != NULL) state_before()->values_do(f);
395 if (state() != NULL) state()->values_do(f);
396 }
397
398 ciType* Invoke::declared_type() const {
399 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci());
400 ciType *t = declared_signature->return_type();
401 assert(t->basic_type() != T_VOID, "need return value of void method?");
402 return t;
403 }
404
405 // Implementation of Contant
406 intx Constant::hash() const {
407 if (state_before() == NULL) {
408 switch (type()->tag()) {
409 case intTag:
410 return HASH2(name(), type()->as_IntConstant()->value());
411 case addressTag:
412 return HASH2(name(), type()->as_AddressConstant()->value());
413 case longTag:
414 {
415 jlong temp = type()->as_LongConstant()->value();
416 return HASH3(name(), high(temp), low(temp));
417 }
418 case floatTag:
419 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
420 case doubleTag:
421 {
422 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
423 return HASH3(name(), high(temp), low(temp));
424 }
425 case objectTag:
426 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
427 return HASH2(name(), type()->as_ObjectType()->constant_value());
428 case metaDataTag:
429 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
430 return HASH2(name(), type()->as_MetadataType()->constant_value());
431 default:
432 ShouldNotReachHere();
433 }
434 }
435 return 0;
436 }
437
438 bool Constant::is_equal(Value v) const {
439 if (v->as_Constant() == NULL) return false;
440
441 switch (type()->tag()) {
442 case intTag:
443 {
444 IntConstant* t1 = type()->as_IntConstant();
445 IntConstant* t2 = v->type()->as_IntConstant();
446 return (t1 != NULL && t2 != NULL &&
447 t1->value() == t2->value());
448 }
449 case longTag:
450 {
451 LongConstant* t1 = type()->as_LongConstant();
452 LongConstant* t2 = v->type()->as_LongConstant();
453 return (t1 != NULL && t2 != NULL &&
454 t1->value() == t2->value());
455 }
456 case floatTag:
457 {
458 FloatConstant* t1 = type()->as_FloatConstant();
459 FloatConstant* t2 = v->type()->as_FloatConstant();
460 return (t1 != NULL && t2 != NULL &&
461 jint_cast(t1->value()) == jint_cast(t2->value()));
462 }
463 case doubleTag:
464 {
465 DoubleConstant* t1 = type()->as_DoubleConstant();
466 DoubleConstant* t2 = v->type()->as_DoubleConstant();
467 return (t1 != NULL && t2 != NULL &&
468 jlong_cast(t1->value()) == jlong_cast(t2->value()));
469 }
470 case objectTag:
471 {
472 ObjectType* t1 = type()->as_ObjectType();
473 ObjectType* t2 = v->type()->as_ObjectType();
474 return (t1 != NULL && t2 != NULL &&
475 t1->is_loaded() && t2->is_loaded() &&
476 t1->constant_value() == t2->constant_value());
477 }
478 case metaDataTag:
479 {
480 MetadataType* t1 = type()->as_MetadataType();
481 MetadataType* t2 = v->type()->as_MetadataType();
482 return (t1 != NULL && t2 != NULL &&
483 t1->is_loaded() && t2->is_loaded() &&
484 t1->constant_value() == t2->constant_value());
485 }
486 default:
487 return false;
488 }
489 }
490
491 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
492 Constant* rc = right->as_Constant();
493 // other is not a constant
494 if (rc == NULL) return not_comparable;
495
496 ValueType* lt = type();
497 ValueType* rt = rc->type();
498 // different types
499 if (lt->base() != rt->base()) return not_comparable;
500 switch (lt->tag()) {
501 case intTag: {
502 int x = lt->as_IntConstant()->value();
503 int y = rt->as_IntConstant()->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 default : break;
512 }
513 break;
514 }
515 case longTag: {
516 jlong x = lt->as_LongConstant()->value();
517 jlong y = rt->as_LongConstant()->value();
518 switch (cond) {
519 case If::eql: return x == y ? cond_true : cond_false;
520 case If::neq: return x != y ? cond_true : cond_false;
521 case If::lss: return x < y ? cond_true : cond_false;
522 case If::leq: return x <= y ? cond_true : cond_false;
523 case If::gtr: return x > y ? cond_true : cond_false;
524 case If::geq: return x >= y ? cond_true : cond_false;
525 default : break;
526 }
527 break;
528 }
529 case objectTag: {
530 ciObject* xvalue = lt->as_ObjectType()->constant_value();
531 ciObject* yvalue = rt->as_ObjectType()->constant_value();
532 assert(xvalue != NULL && yvalue != NULL, "not constants");
533 if (xvalue->is_loaded() && yvalue->is_loaded()) {
534 switch (cond) {
535 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
536 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
537 default : break;
538 }
539 }
540 break;
541 }
542 case metaDataTag: {
543 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
544 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
545 assert(xvalue != NULL && yvalue != NULL, "not constants");
546 if (xvalue->is_loaded() && yvalue->is_loaded()) {
547 switch (cond) {
548 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
549 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
550 default : break;
551 }
552 }
553 break;
554 }
555 default:
556 break;
557 }
558 return not_comparable;
559 }
560
561
562 // Implementation of BlockBegin
563
564 void BlockBegin::set_end(BlockEnd* end) {
565 assert(end != NULL, "should not reset block end to NULL");
566 if (end == _end) {
567 return;
568 }
569 clear_end();
570
571 // Set the new end
572 _end = end;
573
574 _successors.clear();
575 // Now reset successors list based on BlockEnd
576 for (int i = 0; i < end->number_of_sux(); i++) {
577 BlockBegin* sux = end->sux_at(i);
578 _successors.append(sux);
579 sux->_predecessors.append(this);
580 }
581 _end->set_begin(this);
582 }
583
584
585 void BlockBegin::clear_end() {
586 // Must make the predecessors/successors match up with the
587 // BlockEnd's notion.
588 if (_end != NULL) {
589 // disconnect from the old end
590 _end->set_begin(NULL);
591
592 // disconnect this block from it's current successors
593 for (int i = 0; i < _successors.length(); i++) {
594 _successors.at(i)->remove_predecessor(this);
595 }
596 _end = NULL;
597 }
598 }
599
600
601 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
602 // disconnect any edges between from and to
603 #ifndef PRODUCT
604 if (PrintIR && Verbose) {
605 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
606 }
607 #endif
608 for (int s = 0; s < from->number_of_sux();) {
609 BlockBegin* sux = from->sux_at(s);
610 if (sux == to) {
611 int index = sux->_predecessors.find(from);
612 if (index >= 0) {
613 sux->_predecessors.remove_at(index);
614 }
615 from->_successors.remove_at(s);
616 } else {
617 s++;
618 }
619 }
620 }
621
622
623 void BlockBegin::disconnect_from_graph() {
624 // disconnect this block from all other blocks
625 for (int p = 0; p < number_of_preds(); p++) {
626 pred_at(p)->remove_successor(this);
627 }
628 for (int s = 0; s < number_of_sux(); s++) {
629 sux_at(s)->remove_predecessor(this);
630 }
631 }
632
633 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
634 // modify predecessors before substituting successors
635 for (int i = 0; i < number_of_sux(); i++) {
636 if (sux_at(i) == old_sux) {
637 // remove old predecessor before adding new predecessor
638 // otherwise there is a dead predecessor in the list
639 new_sux->remove_predecessor(old_sux);
640 new_sux->add_predecessor(this);
641 }
642 }
643 old_sux->remove_predecessor(this);
644 end()->substitute_sux(old_sux, new_sux);
645 }
646
647
648
649 // In general it is not possible to calculate a value for the field "depth_first_number"
650 // of the inserted block, without recomputing the values of the other blocks
651 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
652 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
653 int bci = sux->bci();
654 // critical edge splitting may introduce a goto after a if and array
655 // bound check elimination may insert a predicate between the if and
656 // goto. The bci of the goto can't be the one of the if otherwise
657 // the state and bci are inconsistent and a deoptimization triggered
658 // by the predicate would lead to incorrect execution/a crash.
659 BlockBegin* new_sux = new BlockBegin(bci);
660
661 // mark this block (special treatment when block order is computed)
662 new_sux->set(critical_edge_split_flag);
663
664 // This goto is not a safepoint.
665 Goto* e = new Goto(sux, false);
666 new_sux->set_next(e, bci);
667 new_sux->set_end(e);
668 // setup states
669 ValueStack* s = end()->state();
670 new_sux->set_state(s->copy(s->kind(), bci));
671 e->set_state(s->copy(s->kind(), bci));
672 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
673 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
674 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
675
676 // link predecessor to new block
677 end()->substitute_sux(sux, new_sux);
678
679 // The ordering needs to be the same, so remove the link that the
680 // set_end call above added and substitute the new_sux for this
681 // block.
682 sux->remove_predecessor(new_sux);
683
684 // the successor could be the target of a switch so it might have
685 // multiple copies of this predecessor, so substitute the new_sux
686 // for the first and delete the rest.
687 bool assigned = false;
688 BlockList& list = sux->_predecessors;
689 for (int i = 0; i < list.length(); i++) {
690 BlockBegin** b = list.adr_at(i);
691 if (*b == this) {
692 if (assigned) {
693 list.remove_at(i);
694 // reprocess this index
695 i--;
696 } else {
697 assigned = true;
698 *b = new_sux;
699 }
700 // link the new block back to it's predecessors.
701 new_sux->add_predecessor(this);
702 }
703 }
704 assert(assigned == true, "should have assigned at least once");
705 return new_sux;
706 }
707
708
709 void BlockBegin::remove_successor(BlockBegin* pred) {
710 int idx;
711 while ((idx = _successors.find(pred)) >= 0) {
712 _successors.remove_at(idx);
713 }
714 }
715
716
717 void BlockBegin::add_predecessor(BlockBegin* pred) {
718 _predecessors.append(pred);
719 }
720
721
722 void BlockBegin::remove_predecessor(BlockBegin* pred) {
723 int idx;
724 while ((idx = _predecessors.find(pred)) >= 0) {
725 _predecessors.remove_at(idx);
726 }
727 }
728
729
730 void BlockBegin::add_exception_handler(BlockBegin* b) {
731 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
732 // add only if not in the list already
733 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
734 }
735
736 int BlockBegin::add_exception_state(ValueStack* state) {
737 assert(is_set(exception_entry_flag), "only for xhandlers");
738 if (_exception_states == NULL) {
739 _exception_states = new ValueStackStack(4);
740 }
741 _exception_states->append(state);
742 return _exception_states->length() - 1;
743 }
744
745
746 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
747 if (!mark.at(block_id())) {
748 mark.at_put(block_id(), true);
749 closure->block_do(this);
750 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
751 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
752 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
753 }
754 }
755
756
757 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
758 if (!mark.at(block_id())) {
759 mark.at_put(block_id(), true);
760 BlockEnd* e = end();
761 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
762 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
763 closure->block_do(this);
764 }
765 }
766
767
768 void BlockBegin::iterate_preorder(BlockClosure* closure) {
769 int mark_len = number_of_blocks();
770 boolArray mark(mark_len, mark_len, false);
771 iterate_preorder(mark, closure);
772 }
773
774
775 void BlockBegin::iterate_postorder(BlockClosure* closure) {
776 int mark_len = number_of_blocks();
777 boolArray mark(mark_len, mark_len, false);
778 iterate_postorder(mark, closure);
779 }
780
781
782 void BlockBegin::block_values_do(ValueVisitor* f) {
783 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
784 }
785
786
787 #ifndef PRODUCT
788 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
789 #else
790 #define TRACE_PHI(coce)
791 #endif
792
793
794 bool BlockBegin::try_merge(ValueStack* new_state) {
795 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
796
797 // local variables used for state iteration
798 int index;
799 Value new_value, existing_value;
800
801 ValueStack* existing_state = state();
802 if (existing_state == NULL) {
803 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
804
805 if (is_set(BlockBegin::was_visited_flag)) {
806 // this actually happens for complicated jsr/ret structures
807 return false; // BAILOUT in caller
808 }
809
810 // copy state because it is altered
811 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
812
813 // Use method liveness to invalidate dead locals
814 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
815 if (liveness.is_valid()) {
816 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
817
818 for_each_local_value(new_state, index, new_value) {
819 if (!liveness.at(index) || new_value->type()->is_illegal()) {
820 new_state->invalidate_local(index);
821 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
822 }
823 }
824 }
825
826 if (is_set(BlockBegin::parser_loop_header_flag)) {
827 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
828
829 for_each_stack_value(new_state, index, new_value) {
830 new_state->setup_phi_for_stack(this, index, NULL, new_value);
831 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));
832 }
833
834 BitMap& requires_phi_function = new_state->scope()->requires_phi_function();
835
836 for_each_local_value(new_state, index, new_value) {
837 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
838 if (requires_phi || !SelectivePhiFunctions) {
839 new_state->setup_phi_for_local(this, index, NULL, new_value);
840 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));
841 }
842 }
843 }
844
845 // initialize state of block
846 set_state(new_state);
847
848 } else if (existing_state->is_same(new_state)) {
849 TRACE_PHI(tty->print_cr("exisiting state found"));
850
851 assert(existing_state->scope() == new_state->scope(), "not matching");
852 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
853 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
854
855 if (is_set(BlockBegin::was_visited_flag)) {
856 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
857
858 if (!is_set(BlockBegin::parser_loop_header_flag)) {
859 // this actually happens for complicated jsr/ret structures
860 return false; // BAILOUT in caller
861 }
862
863 for_each_local_value(existing_state, index, existing_value) {
864 Value new_value = new_state->local_at(index);
865 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
866 // The old code invalidated the phi function here
867 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
868 return false; // BAILOUT in caller
869 }
870 }
871
872 #ifdef ASSERT
873 // check that all necessary phi functions are present
874 for_each_stack_value(existing_state, index, existing_value) {
875 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
876 }
877 for_each_local_value(existing_state, index, existing_value) {
878 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
879 }
880 #endif
881
882 } else {
883 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
884
885 // create necessary phi functions for stack
886 for_each_stack_value(existing_state, index, existing_value) {
887 Value new_value = new_state->stack_at(index);
888 Phi* existing_phi = existing_value->as_Phi();
889
890 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
891 existing_state->setup_phi_for_stack(this, index, existing_value, new_value);
892 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));
893 }
894 }
895
896 // create necessary phi functions for locals
897 for_each_local_value(existing_state, index, existing_value) {
898 Value new_value = new_state->local_at(index);
899 Phi* existing_phi = existing_value->as_Phi();
900
901 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
902 existing_state->invalidate_local(index);
903 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
904 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
905 existing_state->setup_phi_for_local(this, index, existing_value, new_value);
906 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));
907 }
908 }
909 }
910
911 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
912
913 } else {
914 assert(false, "stack or locks not matching (invalid bytecodes)");
915 return false;
916 }
917
918 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
919
920 return true;
921 }
922
923
924 #ifndef PRODUCT
925 void BlockBegin::print_block() {
926 InstructionPrinter ip;
927 print_block(ip, false);
928 }
929
930
931 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
932 ip.print_instr(this); tty->cr();
933 ip.print_stack(this->state()); tty->cr();
934 ip.print_inline_level(this);
935 ip.print_head();
936 for (Instruction* n = next(); n != NULL; n = n->next()) {
937 if (!live_only || n->is_pinned() || n->use_count() > 0) {
938 ip.print_line(n);
939 }
940 }
941 tty->cr();
942 }
943 #endif // PRODUCT
944
945
946 // Implementation of BlockList
947
948 void BlockList::iterate_forward (BlockClosure* closure) {
949 const int l = length();
950 for (int i = 0; i < l; i++) closure->block_do(at(i));
951 }
952
953
954 void BlockList::iterate_backward(BlockClosure* closure) {
955 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
956 }
957
958
959 void BlockList::blocks_do(void f(BlockBegin*)) {
960 for (int i = length() - 1; i >= 0; i--) f(at(i));
961 }
962
963
964 void BlockList::values_do(ValueVisitor* f) {
965 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
966 }
967
968
969 #ifndef PRODUCT
970 void BlockList::print(bool cfg_only, bool live_only) {
971 InstructionPrinter ip;
972 for (int i = 0; i < length(); i++) {
973 BlockBegin* block = at(i);
974 if (cfg_only) {
975 ip.print_instr(block); tty->cr();
976 } else {
977 block->print_block(ip, live_only);
978 }
979 }
980 }
981 #endif // PRODUCT
982
983
984 // Implementation of BlockEnd
985
986 void BlockEnd::set_begin(BlockBegin* begin) {
987 BlockList* sux = NULL;
988 if (begin != NULL) {
989 sux = begin->successors();
990 } else if (this->begin() != NULL) {
991 // copy our sux list
992 BlockList* sux = new BlockList(this->begin()->number_of_sux());
993 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
994 sux->append(this->begin()->sux_at(i));
995 }
996 }
997 _sux = sux;
998 }
999
1000
1001 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
1002 substitute(*_sux, old_sux, new_sux);
1003 }
1004
1005
1006 // Implementation of Phi
1007
1008 // Normal phi functions take their operands from the last instruction of the
1009 // predecessor. Special handling is needed for xhanlder entries because there
1010 // the state of arbitrary instructions are needed.
1011
1012 Value Phi::operand_at(int i) const {
1013 ValueStack* state;
1014 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1015 state = _block->exception_state_at(i);
1016 } else {
1017 state = _block->pred_at(i)->end()->state();
1018 }
1019 assert(state != NULL, "");
1020
1021 if (is_local()) {
1022 return state->local_at(local_index());
1023 } else {
1024 return state->stack_at(stack_index());
1025 }
1026 }
1027
1028
1029 int Phi::operand_count() const {
1030 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1031 return _block->number_of_exception_states();
1032 } else {
1033 return _block->number_of_preds();
1034 }
1035 }
1036
1037 #ifdef ASSERT
1038 // Constructor of Assert
1039 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
1040 , _x(x)
1041 , _cond(cond)
1042 , _y(y)
1043 {
1044 set_flag(UnorderedIsTrueFlag, unordered_is_true);
1045 assert(x->type()->tag() == y->type()->tag(), "types must match");
1046 pin();
1047
1048 stringStream strStream;
1049 Compilation::current()->method()->print_name(&strStream);
1050
1051 stringStream strStream1;
1052 InstructionPrinter ip1(1, &strStream1);
1053 ip1.print_instr(x);
1054
1055 stringStream strStream2;
1056 InstructionPrinter ip2(1, &strStream2);
1057 ip2.print_instr(y);
1058
1059 stringStream ss;
1060 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1061
1062 _message = ss.as_string();
1063 }
1064 #endif
1065
1066 void RangeCheckPredicate::check_state() {
1067 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1068 }
1069
1070 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1071 if (state() != NULL) state()->values_do(f);
1072 }