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 && type->is_value_array_klass()) {
121 ciValueKlass* element_klass = type->as_value_array_klass()->element_klass()->as_value_klass();
122 if (!element_klass->is_loaded() || element_klass->flatten_array()) {
123 // Assume that all unloaded value arrays are not flattenable. If they
124 // turn out to be flattenable, we deoptimize on aaload/aastore.
125 return true;
126 }
127 }
128 }
129
130 return false;
131 }
132
133 #ifndef PRODUCT
134 void Instruction::check_state(ValueStack* state) {
135 if (state != NULL) {
136 state->verify();
137 }
138 }
139
140
141 void Instruction::print() {
142 InstructionPrinter ip;
143 print(ip);
144 }
145
146
147 void Instruction::print_line() {
148 InstructionPrinter ip;
149 ip.print_line(this);
150 }
151
152
153 void Instruction::print(InstructionPrinter& ip) {
154 ip.print_head();
155 ip.print_line(this);
156 tty->cr();
157 }
158 #endif // PRODUCT
159
160
161 // perform constant and interval tests on index value
162 bool AccessIndexed::compute_needs_range_check() {
163 if (length()) {
164 Constant* clength = length()->as_Constant();
165 Constant* cindex = index()->as_Constant();
166 if (clength && cindex) {
167 IntConstant* l = clength->type()->as_IntConstant();
168 IntConstant* i = cindex->type()->as_IntConstant();
169 if (l && i && i->value() < l->value() && i->value() >= 0) {
170 return false;
171 }
172 }
173 }
174
175 if (!this->check_flag(NeedsRangeCheckFlag)) {
176 return false;
177 }
178
179 return true;
180 }
181
182
183 ciType* Constant::exact_type() const {
184 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) {
185 return type()->as_ObjectType()->exact_type();
186 }
187 return NULL;
188 }
189
190 ciType* LoadIndexed::exact_type() const {
191 ciType* array_type = array()->exact_type();
192 if (array_type != NULL) {
193 assert(array_type->is_array_klass(), "what else?");
194 ciArrayKlass* ak = (ciArrayKlass*)array_type;
195
196 if (ak->element_type()->is_instance_klass()) {
197 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
198 if (ik->is_loaded() && ik->is_final()) {
199 return ik;
200 }
201 }
202 }
203 return Instruction::exact_type();
204 }
205
206
207 ciType* LoadIndexed::declared_type() const {
208 ciType* array_type = array()->declared_type();
209 if (array_type == NULL || !array_type->is_loaded()) {
210 return NULL;
211 }
212 assert(array_type->is_array_klass(), "what else?");
213 ciArrayKlass* ak = (ciArrayKlass*)array_type;
214 return ak->element_type();
215 }
216
217
218 ciType* LoadField::declared_type() const {
219 return field()->type();
220 }
221
222
223 ciType* NewTypeArray::exact_type() const {
224 return ciTypeArrayKlass::make(elt_type());
225 }
226
227 ciType* NewObjectArray::exact_type() const {
228 ciKlass* element_klass = klass();
229 if (element_klass->is_valuetype()) {
230 return ciValueArrayKlass::make(element_klass);
231 } else {
232 return ciObjArrayKlass::make(element_klass);
233 }
234 }
235
236 ciType* NewMultiArray::exact_type() const {
237 return _klass;
238 }
239
240 ciType* NewArray::declared_type() const {
241 return exact_type();
242 }
243
244 ciType* NewInstance::exact_type() const {
245 return klass();
246 }
247
248 ciType* NewInstance::declared_type() const {
249 return exact_type();
250 }
251
252 Value NewValueTypeInstance::depends_on() {
253 if (_depends_on != this) {
254 if (_depends_on->as_NewValueTypeInstance() != NULL) {
255 return _depends_on->as_NewValueTypeInstance()->depends_on();
256 }
257 }
258 return _depends_on;
259 }
260
261 ciType* NewValueTypeInstance::exact_type() const {
262 return klass();
263 }
264
265 ciType* NewValueTypeInstance::declared_type() const {
266 return exact_type();
267 }
268
269 ciType* CheckCast::declared_type() const {
270 return klass();
271 }
272
273 // Implementation of ArithmeticOp
274
275 bool ArithmeticOp::is_commutative() const {
276 switch (op()) {
277 case Bytecodes::_iadd: // fall through
278 case Bytecodes::_ladd: // fall through
279 case Bytecodes::_fadd: // fall through
280 case Bytecodes::_dadd: // fall through
281 case Bytecodes::_imul: // fall through
282 case Bytecodes::_lmul: // fall through
283 case Bytecodes::_fmul: // fall through
284 case Bytecodes::_dmul: return true;
285 default : return false;
286 }
287 }
288
289
290 bool ArithmeticOp::can_trap() const {
291 switch (op()) {
292 case Bytecodes::_idiv: // fall through
293 case Bytecodes::_ldiv: // fall through
294 case Bytecodes::_irem: // fall through
295 case Bytecodes::_lrem: return true;
296 default : return false;
297 }
298 }
299
300
301 // Implementation of LogicOp
302
303 bool LogicOp::is_commutative() const {
304 #ifdef ASSERT
305 switch (op()) {
306 case Bytecodes::_iand: // fall through
307 case Bytecodes::_land: // fall through
308 case Bytecodes::_ior : // fall through
309 case Bytecodes::_lor : // fall through
310 case Bytecodes::_ixor: // fall through
311 case Bytecodes::_lxor: break;
312 default : ShouldNotReachHere(); break;
313 }
314 #endif
315 // all LogicOps are commutative
316 return true;
317 }
318
319
320 // Implementation of IfOp
321
322 bool IfOp::is_commutative() const {
323 return cond() == eql || cond() == neq;
324 }
325
326
327 // Implementation of StateSplit
328
329 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
330 NOT_PRODUCT(bool assigned = false;)
331 for (int i = 0; i < list.length(); i++) {
332 BlockBegin** b = list.adr_at(i);
333 if (*b == old_block) {
334 *b = new_block;
335 NOT_PRODUCT(assigned = true;)
336 }
337 }
338 assert(assigned == true, "should have assigned at least once");
339 }
340
341
342 IRScope* StateSplit::scope() const {
343 return _state->scope();
344 }
345
346
347 void StateSplit::state_values_do(ValueVisitor* f) {
348 Instruction::state_values_do(f);
349 if (state() != NULL) state()->values_do(f);
350 }
351
352
353 void BlockBegin::state_values_do(ValueVisitor* f) {
354 StateSplit::state_values_do(f);
355
356 if (is_set(BlockBegin::exception_entry_flag)) {
357 for (int i = 0; i < number_of_exception_states(); i++) {
358 exception_state_at(i)->values_do(f);
359 }
360 }
361 }
362
363
364 // Implementation of Invoke
365
366
367 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
368 int vtable_index, ciMethod* target, ValueStack* state_before)
369 : StateSplit(result_type, state_before)
370 , _code(code)
371 , _recv(recv)
372 , _args(args)
373 , _vtable_index(vtable_index)
374 , _target(target)
375 {
376 set_flag(TargetIsLoadedFlag, target->is_loaded());
377 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
378 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
379
380 assert(args != NULL, "args must exist");
381 #ifdef ASSERT
382 AssertValues assert_value;
383 values_do(&assert_value);
384 #endif
385
386 // provide an initial guess of signature size.
387 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
388 if (has_receiver()) {
389 _signature->append(as_BasicType(receiver()->type()));
390 }
391 for (int i = 0; i < number_of_arguments(); i++) {
392 ValueType* t = argument_at(i)->type();
393 BasicType bt = as_BasicType(t);
394 _signature->append(bt);
395 }
396 }
397
398
399 void Invoke::state_values_do(ValueVisitor* f) {
400 StateSplit::state_values_do(f);
401 if (state_before() != NULL) state_before()->values_do(f);
402 if (state() != NULL) state()->values_do(f);
403 }
404
405 ciType* Invoke::declared_type() const {
406 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci());
407 ciType *t = declared_signature->return_type();
408 assert(t->basic_type() != T_VOID, "need return value of void method?");
409 return t;
410 }
411
412 // Implementation of Contant
413 intx Constant::hash() const {
414 if (state_before() == NULL) {
415 switch (type()->tag()) {
416 case intTag:
417 return HASH2(name(), type()->as_IntConstant()->value());
418 case addressTag:
419 return HASH2(name(), type()->as_AddressConstant()->value());
420 case longTag:
421 {
422 jlong temp = type()->as_LongConstant()->value();
423 return HASH3(name(), high(temp), low(temp));
424 }
425 case floatTag:
426 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
427 case doubleTag:
428 {
429 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
430 return HASH3(name(), high(temp), low(temp));
431 }
432 case objectTag:
433 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
434 return HASH2(name(), type()->as_ObjectType()->constant_value());
435 case metaDataTag:
436 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
437 return HASH2(name(), type()->as_MetadataType()->constant_value());
438 default:
439 ShouldNotReachHere();
440 }
441 }
442 return 0;
443 }
444
445 bool Constant::is_equal(Value v) const {
446 if (v->as_Constant() == NULL) return false;
447
448 switch (type()->tag()) {
449 case intTag:
450 {
451 IntConstant* t1 = type()->as_IntConstant();
452 IntConstant* t2 = v->type()->as_IntConstant();
453 return (t1 != NULL && t2 != NULL &&
454 t1->value() == t2->value());
455 }
456 case longTag:
457 {
458 LongConstant* t1 = type()->as_LongConstant();
459 LongConstant* t2 = v->type()->as_LongConstant();
460 return (t1 != NULL && t2 != NULL &&
461 t1->value() == t2->value());
462 }
463 case floatTag:
464 {
465 FloatConstant* t1 = type()->as_FloatConstant();
466 FloatConstant* t2 = v->type()->as_FloatConstant();
467 return (t1 != NULL && t2 != NULL &&
468 jint_cast(t1->value()) == jint_cast(t2->value()));
469 }
470 case doubleTag:
471 {
472 DoubleConstant* t1 = type()->as_DoubleConstant();
473 DoubleConstant* t2 = v->type()->as_DoubleConstant();
474 return (t1 != NULL && t2 != NULL &&
475 jlong_cast(t1->value()) == jlong_cast(t2->value()));
476 }
477 case objectTag:
478 {
479 ObjectType* t1 = type()->as_ObjectType();
480 ObjectType* t2 = v->type()->as_ObjectType();
481 return (t1 != NULL && t2 != NULL &&
482 t1->is_loaded() && t2->is_loaded() &&
483 t1->constant_value() == t2->constant_value());
484 }
485 case metaDataTag:
486 {
487 MetadataType* t1 = type()->as_MetadataType();
488 MetadataType* t2 = v->type()->as_MetadataType();
489 return (t1 != NULL && t2 != NULL &&
490 t1->is_loaded() && t2->is_loaded() &&
491 t1->constant_value() == t2->constant_value());
492 }
493 default:
494 return false;
495 }
496 }
497
498 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
499 Constant* rc = right->as_Constant();
500 // other is not a constant
501 if (rc == NULL) return not_comparable;
502
503 ValueType* lt = type();
504 ValueType* rt = rc->type();
505 // different types
506 if (lt->base() != rt->base()) return not_comparable;
507 switch (lt->tag()) {
508 case intTag: {
509 int x = lt->as_IntConstant()->value();
510 int y = rt->as_IntConstant()->value();
511 switch (cond) {
512 case If::eql: return x == y ? cond_true : cond_false;
513 case If::neq: return x != y ? cond_true : cond_false;
514 case If::lss: return x < y ? cond_true : cond_false;
515 case If::leq: return x <= y ? cond_true : cond_false;
516 case If::gtr: return x > y ? cond_true : cond_false;
517 case If::geq: return x >= y ? cond_true : cond_false;
518 default : break;
519 }
520 break;
521 }
522 case longTag: {
523 jlong x = lt->as_LongConstant()->value();
524 jlong y = rt->as_LongConstant()->value();
525 switch (cond) {
526 case If::eql: return x == y ? cond_true : cond_false;
527 case If::neq: return x != y ? cond_true : cond_false;
528 case If::lss: return x < y ? cond_true : cond_false;
529 case If::leq: return x <= y ? cond_true : cond_false;
530 case If::gtr: return x > y ? cond_true : cond_false;
531 case If::geq: return x >= y ? cond_true : cond_false;
532 default : break;
533 }
534 break;
535 }
536 case objectTag: {
537 ciObject* xvalue = lt->as_ObjectType()->constant_value();
538 ciObject* yvalue = rt->as_ObjectType()->constant_value();
539 assert(xvalue != NULL && yvalue != NULL, "not constants");
540 if (xvalue->is_loaded() && yvalue->is_loaded()) {
541 switch (cond) {
542 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
543 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
544 default : break;
545 }
546 }
547 break;
548 }
549 case metaDataTag: {
550 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
551 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
552 assert(xvalue != NULL && yvalue != NULL, "not constants");
553 if (xvalue->is_loaded() && yvalue->is_loaded()) {
554 switch (cond) {
555 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
556 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
557 default : break;
558 }
559 }
560 break;
561 }
562 default:
563 break;
564 }
565 return not_comparable;
566 }
567
568
569 // Implementation of BlockBegin
570
571 void BlockBegin::set_end(BlockEnd* end) {
572 assert(end != NULL, "should not reset block end to NULL");
573 if (end == _end) {
574 return;
575 }
576 clear_end();
577
578 // Set the new end
579 _end = end;
580
581 _successors.clear();
582 // Now reset successors list based on BlockEnd
583 for (int i = 0; i < end->number_of_sux(); i++) {
584 BlockBegin* sux = end->sux_at(i);
585 _successors.append(sux);
586 sux->_predecessors.append(this);
587 }
588 _end->set_begin(this);
589 }
590
591
592 void BlockBegin::clear_end() {
593 // Must make the predecessors/successors match up with the
594 // BlockEnd's notion.
595 if (_end != NULL) {
596 // disconnect from the old end
597 _end->set_begin(NULL);
598
599 // disconnect this block from it's current successors
600 for (int i = 0; i < _successors.length(); i++) {
601 _successors.at(i)->remove_predecessor(this);
602 }
603 _end = NULL;
604 }
605 }
606
607
608 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
609 // disconnect any edges between from and to
610 #ifndef PRODUCT
611 if (PrintIR && Verbose) {
612 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
613 }
614 #endif
615 for (int s = 0; s < from->number_of_sux();) {
616 BlockBegin* sux = from->sux_at(s);
617 if (sux == to) {
618 int index = sux->_predecessors.find(from);
619 if (index >= 0) {
620 sux->_predecessors.remove_at(index);
621 }
622 from->_successors.remove_at(s);
623 } else {
624 s++;
625 }
626 }
627 }
628
629
630 void BlockBegin::disconnect_from_graph() {
631 // disconnect this block from all other blocks
632 for (int p = 0; p < number_of_preds(); p++) {
633 pred_at(p)->remove_successor(this);
634 }
635 for (int s = 0; s < number_of_sux(); s++) {
636 sux_at(s)->remove_predecessor(this);
637 }
638 }
639
640 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
641 // modify predecessors before substituting successors
642 for (int i = 0; i < number_of_sux(); i++) {
643 if (sux_at(i) == old_sux) {
644 // remove old predecessor before adding new predecessor
645 // otherwise there is a dead predecessor in the list
646 new_sux->remove_predecessor(old_sux);
647 new_sux->add_predecessor(this);
648 }
649 }
650 old_sux->remove_predecessor(this);
651 end()->substitute_sux(old_sux, new_sux);
652 }
653
654
655
656 // In general it is not possible to calculate a value for the field "depth_first_number"
657 // of the inserted block, without recomputing the values of the other blocks
658 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
659 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
660 int bci = sux->bci();
661 // critical edge splitting may introduce a goto after a if and array
662 // bound check elimination may insert a predicate between the if and
663 // goto. The bci of the goto can't be the one of the if otherwise
664 // the state and bci are inconsistent and a deoptimization triggered
665 // by the predicate would lead to incorrect execution/a crash.
666 BlockBegin* new_sux = new BlockBegin(bci);
667
668 // mark this block (special treatment when block order is computed)
669 new_sux->set(critical_edge_split_flag);
670
671 // This goto is not a safepoint.
672 Goto* e = new Goto(sux, false);
673 new_sux->set_next(e, bci);
674 new_sux->set_end(e);
675 // setup states
676 ValueStack* s = end()->state();
677 new_sux->set_state(s->copy(s->kind(), bci));
678 e->set_state(s->copy(s->kind(), bci));
679 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
680 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
681 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
682
683 // link predecessor to new block
684 end()->substitute_sux(sux, new_sux);
685
686 // The ordering needs to be the same, so remove the link that the
687 // set_end call above added and substitute the new_sux for this
688 // block.
689 sux->remove_predecessor(new_sux);
690
691 // the successor could be the target of a switch so it might have
692 // multiple copies of this predecessor, so substitute the new_sux
693 // for the first and delete the rest.
694 bool assigned = false;
695 BlockList& list = sux->_predecessors;
696 for (int i = 0; i < list.length(); i++) {
697 BlockBegin** b = list.adr_at(i);
698 if (*b == this) {
699 if (assigned) {
700 list.remove_at(i);
701 // reprocess this index
702 i--;
703 } else {
704 assigned = true;
705 *b = new_sux;
706 }
707 // link the new block back to it's predecessors.
708 new_sux->add_predecessor(this);
709 }
710 }
711 assert(assigned == true, "should have assigned at least once");
712 return new_sux;
713 }
714
715
716 void BlockBegin::remove_successor(BlockBegin* pred) {
717 int idx;
718 while ((idx = _successors.find(pred)) >= 0) {
719 _successors.remove_at(idx);
720 }
721 }
722
723
724 void BlockBegin::add_predecessor(BlockBegin* pred) {
725 _predecessors.append(pred);
726 }
727
728
729 void BlockBegin::remove_predecessor(BlockBegin* pred) {
730 int idx;
731 while ((idx = _predecessors.find(pred)) >= 0) {
732 _predecessors.remove_at(idx);
733 }
734 }
735
736
737 void BlockBegin::add_exception_handler(BlockBegin* b) {
738 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
739 // add only if not in the list already
740 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
741 }
742
743 int BlockBegin::add_exception_state(ValueStack* state) {
744 assert(is_set(exception_entry_flag), "only for xhandlers");
745 if (_exception_states == NULL) {
746 _exception_states = new ValueStackStack(4);
747 }
748 _exception_states->append(state);
749 return _exception_states->length() - 1;
750 }
751
752
753 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
754 if (!mark.at(block_id())) {
755 mark.at_put(block_id(), true);
756 closure->block_do(this);
757 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
758 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
759 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
760 }
761 }
762
763
764 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
765 if (!mark.at(block_id())) {
766 mark.at_put(block_id(), true);
767 BlockEnd* e = end();
768 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
769 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
770 closure->block_do(this);
771 }
772 }
773
774
775 void BlockBegin::iterate_preorder(BlockClosure* closure) {
776 int mark_len = number_of_blocks();
777 boolArray mark(mark_len, mark_len, false);
778 iterate_preorder(mark, closure);
779 }
780
781
782 void BlockBegin::iterate_postorder(BlockClosure* closure) {
783 int mark_len = number_of_blocks();
784 boolArray mark(mark_len, mark_len, false);
785 iterate_postorder(mark, closure);
786 }
787
788
789 void BlockBegin::block_values_do(ValueVisitor* f) {
790 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
791 }
792
793
794 #ifndef PRODUCT
795 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
796 #else
797 #define TRACE_PHI(coce)
798 #endif
799
800
801 bool BlockBegin::try_merge(ValueStack* new_state) {
802 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
803
804 // local variables used for state iteration
805 int index;
806 Value new_value, existing_value;
807
808 ValueStack* existing_state = state();
809 if (existing_state == NULL) {
810 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
811
812 if (is_set(BlockBegin::was_visited_flag)) {
813 // this actually happens for complicated jsr/ret structures
814 return false; // BAILOUT in caller
815 }
816
817 // copy state because it is altered
818 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
819
820 // Use method liveness to invalidate dead locals
821 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
822 if (liveness.is_valid()) {
823 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
824
825 for_each_local_value(new_state, index, new_value) {
826 if (!liveness.at(index) || new_value->type()->is_illegal()) {
827 new_state->invalidate_local(index);
828 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
829 }
830 }
831 }
832
833 if (is_set(BlockBegin::parser_loop_header_flag)) {
834 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
835
836 for_each_stack_value(new_state, index, new_value) {
837 new_state->setup_phi_for_stack(this, index, NULL, new_value);
838 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));
839 }
840
841 BitMap& requires_phi_function = new_state->scope()->requires_phi_function();
842
843 for_each_local_value(new_state, index, new_value) {
844 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
845 if (requires_phi || !SelectivePhiFunctions) {
846 new_state->setup_phi_for_local(this, index, NULL, new_value);
847 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));
848 }
849 }
850 }
851
852 // initialize state of block
853 set_state(new_state);
854
855 } else if (existing_state->is_same(new_state)) {
856 TRACE_PHI(tty->print_cr("exisiting state found"));
857
858 assert(existing_state->scope() == new_state->scope(), "not matching");
859 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
860 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
861
862 if (is_set(BlockBegin::was_visited_flag)) {
863 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
864
865 if (!is_set(BlockBegin::parser_loop_header_flag)) {
866 // this actually happens for complicated jsr/ret structures
867 return false; // BAILOUT in caller
868 }
869
870 for_each_local_value(existing_state, index, existing_value) {
871 Value new_value = new_state->local_at(index);
872 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
873 // The old code invalidated the phi function here
874 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out
875 return false; // BAILOUT in caller
876 }
877 }
878
879 #ifdef ASSERT
880 // check that all necessary phi functions are present
881 for_each_stack_value(existing_state, index, existing_value) {
882 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
883 }
884 for_each_local_value(existing_state, index, existing_value) {
885 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
886 }
887 #endif
888
889 } else {
890 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
891
892 // create necessary phi functions for stack
893 for_each_stack_value(existing_state, index, existing_value) {
894 Value new_value = new_state->stack_at(index);
895 Phi* existing_phi = existing_value->as_Phi();
896
897 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
898 existing_state->setup_phi_for_stack(this, index, existing_value, new_value);
899 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));
900 }
901 }
902
903 // create necessary phi functions for locals
904 for_each_local_value(existing_state, index, existing_value) {
905 Value new_value = new_state->local_at(index);
906 Phi* existing_phi = existing_value->as_Phi();
907
908 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
909 existing_state->invalidate_local(index);
910 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
911 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
912 existing_state->setup_phi_for_local(this, index, existing_value, new_value);
913 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));
914 }
915 }
916 }
917
918 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
919
920 } else {
921 assert(false, "stack or locks not matching (invalid bytecodes)");
922 return false;
923 }
924
925 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
926
927 return true;
928 }
929
930
931 #ifndef PRODUCT
932 void BlockBegin::print_block() {
933 InstructionPrinter ip;
934 print_block(ip, false);
935 }
936
937
938 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
939 ip.print_instr(this); tty->cr();
940 ip.print_stack(this->state()); tty->cr();
941 ip.print_inline_level(this);
942 ip.print_head();
943 for (Instruction* n = next(); n != NULL; n = n->next()) {
944 if (!live_only || n->is_pinned() || n->use_count() > 0) {
945 ip.print_line(n);
946 }
947 }
948 tty->cr();
949 }
950 #endif // PRODUCT
951
952
953 // Implementation of BlockList
954
955 void BlockList::iterate_forward (BlockClosure* closure) {
956 const int l = length();
957 for (int i = 0; i < l; i++) closure->block_do(at(i));
958 }
959
960
961 void BlockList::iterate_backward(BlockClosure* closure) {
962 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
963 }
964
965
966 void BlockList::blocks_do(void f(BlockBegin*)) {
967 for (int i = length() - 1; i >= 0; i--) f(at(i));
968 }
969
970
971 void BlockList::values_do(ValueVisitor* f) {
972 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
973 }
974
975
976 #ifndef PRODUCT
977 void BlockList::print(bool cfg_only, bool live_only) {
978 InstructionPrinter ip;
979 for (int i = 0; i < length(); i++) {
980 BlockBegin* block = at(i);
981 if (cfg_only) {
982 ip.print_instr(block); tty->cr();
983 } else {
984 block->print_block(ip, live_only);
985 }
986 }
987 }
988 #endif // PRODUCT
989
990
991 // Implementation of BlockEnd
992
993 void BlockEnd::set_begin(BlockBegin* begin) {
994 BlockList* sux = NULL;
995 if (begin != NULL) {
996 sux = begin->successors();
997 } else if (this->begin() != NULL) {
998 // copy our sux list
999 BlockList* sux = new BlockList(this->begin()->number_of_sux());
1000 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
1001 sux->append(this->begin()->sux_at(i));
1002 }
1003 }
1004 _sux = sux;
1005 }
1006
1007
1008 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
1009 substitute(*_sux, old_sux, new_sux);
1010 }
1011
1012
1013 // Implementation of Phi
1014
1015 // Normal phi functions take their operands from the last instruction of the
1016 // predecessor. Special handling is needed for xhanlder entries because there
1017 // the state of arbitrary instructions are needed.
1018
1019 Value Phi::operand_at(int i) const {
1020 ValueStack* state;
1021 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1022 state = _block->exception_state_at(i);
1023 } else {
1024 state = _block->pred_at(i)->end()->state();
1025 }
1026 assert(state != NULL, "");
1027
1028 if (is_local()) {
1029 return state->local_at(local_index());
1030 } else {
1031 return state->stack_at(stack_index());
1032 }
1033 }
1034
1035
1036 int Phi::operand_count() const {
1037 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1038 return _block->number_of_exception_states();
1039 } else {
1040 return _block->number_of_preds();
1041 }
1042 }
1043
1044 #ifdef ASSERT
1045 // Constructor of Assert
1046 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
1047 , _x(x)
1048 , _cond(cond)
1049 , _y(y)
1050 {
1051 set_flag(UnorderedIsTrueFlag, unordered_is_true);
1052 assert(x->type()->tag() == y->type()->tag(), "types must match");
1053 pin();
1054
1055 stringStream strStream;
1056 Compilation::current()->method()->print_name(&strStream);
1057
1058 stringStream strStream1;
1059 InstructionPrinter ip1(1, &strStream1);
1060 ip1.print_instr(x);
1061
1062 stringStream strStream2;
1063 InstructionPrinter ip2(1, &strStream2);
1064 ip2.print_instr(y);
1065
1066 stringStream ss;
1067 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1068
1069 _message = ss.as_string();
1070 }
1071 #endif
1072
1073 void RangeCheckPredicate::check_state() {
1074 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1075 }
1076
1077 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1078 if (state() != NULL) state()->values_do(f);
1079 }