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