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
33
34 // Implementation of Instruction
35
36
37 int Instruction::dominator_depth() {
38 int result = -1;
39 if (block()) {
40 result = block()->dominator_depth();
41 }
42 assert(result != -1 || this->as_Local(), "Only locals have dominator depth -1");
43 return result;
44 }
45
46 Instruction::Condition Instruction::mirror(Condition cond) {
47 switch (cond) {
48 case eql: return eql;
49 case neq: return neq;
50 case lss: return gtr;
51 case leq: return geq;
52 case gtr: return lss;
53 case geq: return leq;
54 case aeq: return beq;
55 case beq: return aeq;
56 }
57 ShouldNotReachHere();
58 return eql;
59 }
60
61
62 Instruction::Condition Instruction::negate(Condition cond) {
63 switch (cond) {
64 case eql: return neq;
65 case neq: return eql;
66 case lss: return geq;
67 case leq: return gtr;
68 case gtr: return leq;
69 case geq: return lss;
70 case aeq: assert(false, "Above equal cannot be negated");
71 case beq: assert(false, "Below equal cannot be negated");
72 }
73 ShouldNotReachHere();
74 return eql;
75 }
76
77 void Instruction::update_exception_state(ValueStack* state) {
78 if (state != NULL && (state->kind() == ValueStack::EmptyExceptionState || state->kind() == ValueStack::ExceptionState)) {
79 assert(state->kind() == ValueStack::EmptyExceptionState || Compilation::current()->env()->should_retain_local_variables(), "unexpected state kind");
80 _exception_state = state;
81 } else {
82 _exception_state = NULL;
83 }
84 }
85
86 // Prev without need to have BlockBegin
87 Instruction* Instruction::prev() {
88 Instruction* p = NULL;
89 Instruction* q = block();
90 while (q != this) {
91 assert(q != NULL, "this is not in the block's instruction list");
92 p = q; q = q->next();
93 }
94 return p;
95 }
96
97
98 void Instruction::state_values_do(ValueVisitor* f) {
99 if (state_before() != NULL) {
100 state_before()->values_do(f);
101 }
102 if (exception_state() != NULL){
103 exception_state()->values_do(f);
104 }
105 }
106
107 ciType* Instruction::exact_type() const {
108 ciType* t = declared_type();
109 if (t != NULL && t->is_klass()) {
110 return t->as_klass()->exact_klass();
111 }
112 return NULL;
113 }
114
115
116 #ifndef PRODUCT
117 void Instruction::check_state(ValueStack* state) {
118 if (state != NULL) {
119 state->verify();
120 }
121 }
122
123
124 void Instruction::print() {
125 InstructionPrinter ip;
126 print(ip);
127 }
128
129
130 void Instruction::print_line() {
131 InstructionPrinter ip;
132 ip.print_line(this);
133 }
134
135
136 void Instruction::print(InstructionPrinter& ip) {
137 ip.print_head();
138 ip.print_line(this);
139 tty->cr();
140 }
141 #endif // PRODUCT
142
143
144 // perform constant and interval tests on index value
145 bool AccessIndexed::compute_needs_range_check() {
146 if (length()) {
147 Constant* clength = length()->as_Constant();
148 Constant* cindex = index()->as_Constant();
149 if (clength && cindex) {
150 IntConstant* l = clength->type()->as_IntConstant();
151 IntConstant* i = cindex->type()->as_IntConstant();
152 if (l && i && i->value() < l->value() && i->value() >= 0) {
153 return false;
154 }
155 }
156 }
157
158 if (!this->check_flag(NeedsRangeCheckFlag)) {
159 return false;
160 }
161
162 return true;
163 }
164
165
166 ciType* Constant::exact_type() const {
167 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) {
168 return type()->as_ObjectType()->exact_type();
169 }
170 return NULL;
171 }
172
173 ciType* LoadIndexed::exact_type() const {
174 ciType* array_type = array()->exact_type();
175 if (array_type != NULL) {
176 assert(array_type->is_array_klass(), "what else?");
177 ciArrayKlass* ak = (ciArrayKlass*)array_type;
178
179 if (ak->element_type()->is_instance_klass()) {
180 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
181 if (ik->is_loaded() && ik->is_final()) {
182 return ik;
183 }
184 }
185 }
186 return Instruction::exact_type();
187 }
188
189
190 ciType* LoadIndexed::declared_type() const {
191 ciType* array_type = array()->declared_type();
192 if (array_type == NULL || !array_type->is_loaded()) {
193 return NULL;
194 }
195 assert(array_type->is_array_klass(), "what else?");
196 ciArrayKlass* ak = (ciArrayKlass*)array_type;
197 return ak->element_type();
198 }
199
200
201 ciType* LoadField::declared_type() const {
202 return field()->type();
203 }
204
205
206 ciType* NewTypeArray::exact_type() const {
207 return ciTypeArrayKlass::make(elt_type());
208 }
209
210 ciType* NewObjectArray::exact_type() const {
211 return ciObjArrayKlass::make(klass());
212 }
213
214 ciType* NewArray::declared_type() const {
215 return exact_type();
216 }
217
218 ciType* NewInstance::exact_type() const {
219 return klass();
220 }
221
222 ciType* NewInstance::declared_type() const {
223 return exact_type();
224 }
225
226 ciType* CheckCast::declared_type() const {
227 return klass();
228 }
229
230 // Implementation of ArithmeticOp
231
232 bool ArithmeticOp::is_commutative() const {
233 switch (op()) {
234 case Bytecodes::_iadd: // fall through
235 case Bytecodes::_ladd: // fall through
236 case Bytecodes::_fadd: // fall through
237 case Bytecodes::_dadd: // fall through
238 case Bytecodes::_imul: // fall through
239 case Bytecodes::_lmul: // fall through
240 case Bytecodes::_fmul: // fall through
241 case Bytecodes::_dmul: return true;
242 default : return false;
243 }
244 }
245
246
247 bool ArithmeticOp::can_trap() const {
248 switch (op()) {
249 case Bytecodes::_idiv: // fall through
250 case Bytecodes::_ldiv: // fall through
251 case Bytecodes::_irem: // fall through
252 case Bytecodes::_lrem: return true;
253 default : return false;
254 }
255 }
256
257
258 // Implementation of LogicOp
259
260 bool LogicOp::is_commutative() const {
261 #ifdef ASSERT
262 switch (op()) {
263 case Bytecodes::_iand: // fall through
264 case Bytecodes::_land: // fall through
265 case Bytecodes::_ior : // fall through
266 case Bytecodes::_lor : // fall through
267 case Bytecodes::_ixor: // fall through
268 case Bytecodes::_lxor: break;
269 default : ShouldNotReachHere(); break;
270 }
271 #endif
272 // all LogicOps are commutative
273 return true;
274 }
275
276
277 // Implementation of IfOp
278
279 bool IfOp::is_commutative() const {
280 return cond() == eql || cond() == neq;
281 }
282
283
284 // Implementation of StateSplit
285
286 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
287 NOT_PRODUCT(bool assigned = false;)
288 for (int i = 0; i < list.length(); i++) {
289 BlockBegin** b = list.adr_at(i);
290 if (*b == old_block) {
291 *b = new_block;
292 NOT_PRODUCT(assigned = true;)
293 }
294 }
295 assert(assigned == true, "should have assigned at least once");
296 }
297
298
299 IRScope* StateSplit::scope() const {
300 return _state->scope();
301 }
302
303
304 void StateSplit::state_values_do(ValueVisitor* f) {
305 Instruction::state_values_do(f);
306 if (state() != NULL) state()->values_do(f);
307 }
308
309
310 void BlockBegin::state_values_do(ValueVisitor* f) {
311 StateSplit::state_values_do(f);
312
313 if (is_set(BlockBegin::exception_entry_flag)) {
314 for (int i = 0; i < number_of_exception_states(); i++) {
315 exception_state_at(i)->values_do(f);
316 }
317 }
318 }
319
320
321 // Implementation of Invoke
322
323
324 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
325 int vtable_index, ciMethod* target, ValueStack* state_before)
326 : StateSplit(result_type, state_before)
327 , _code(code)
328 , _recv(recv)
329 , _args(args)
330 , _vtable_index(vtable_index)
331 , _target(target)
332 {
333 set_flag(TargetIsLoadedFlag, target->is_loaded());
334 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
335 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
336
337 assert(args != NULL, "args must exist");
338 #ifdef ASSERT
339 AssertValues assert_value;
340 values_do(&assert_value);
341 #endif
342
343 // provide an initial guess of signature size.
344 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
345 if (has_receiver()) {
346 _signature->append(as_BasicType(receiver()->type()));
347 }
348 for (int i = 0; i < number_of_arguments(); i++) {
349 ValueType* t = argument_at(i)->type();
350 BasicType bt = as_BasicType(t);
351 _signature->append(bt);
352 }
353 }
354
355
356 void Invoke::state_values_do(ValueVisitor* f) {
357 StateSplit::state_values_do(f);
358 if (state_before() != NULL) state_before()->values_do(f);
359 if (state() != NULL) state()->values_do(f);
360 }
361
362 ciType* Invoke::declared_type() const {
363 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci());
364 ciType *t = declared_signature->return_type();
365 assert(t->basic_type() != T_VOID, "need return value of void method?");
366 return t;
367 }
368
369 // Implementation of Contant
370 intx Constant::hash() const {
371 if (state_before() == NULL) {
372 switch (type()->tag()) {
373 case intTag:
374 return HASH2(name(), type()->as_IntConstant()->value());
375 case addressTag:
376 return HASH2(name(), type()->as_AddressConstant()->value());
377 case longTag:
378 {
379 jlong temp = type()->as_LongConstant()->value();
380 return HASH3(name(), high(temp), low(temp));
381 }
382 case floatTag:
383 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
384 case doubleTag:
385 {
386 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
387 return HASH3(name(), high(temp), low(temp));
388 }
389 case objectTag:
390 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
391 return HASH2(name(), type()->as_ObjectType()->constant_value());
392 case metaDataTag:
393 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
394 return HASH2(name(), type()->as_MetadataType()->constant_value());
395 default:
396 ShouldNotReachHere();
397 }
398 }
399 return 0;
400 }
401
402 bool Constant::is_equal(Value v) const {
403 if (v->as_Constant() == NULL) return false;
404
405 switch (type()->tag()) {
406 case intTag:
407 {
408 IntConstant* t1 = type()->as_IntConstant();
409 IntConstant* t2 = v->type()->as_IntConstant();
410 return (t1 != NULL && t2 != NULL &&
411 t1->value() == t2->value());
412 }
413 case longTag:
414 {
415 LongConstant* t1 = type()->as_LongConstant();
416 LongConstant* t2 = v->type()->as_LongConstant();
417 return (t1 != NULL && t2 != NULL &&
418 t1->value() == t2->value());
419 }
420 case floatTag:
421 {
422 FloatConstant* t1 = type()->as_FloatConstant();
423 FloatConstant* t2 = v->type()->as_FloatConstant();
424 return (t1 != NULL && t2 != NULL &&
425 jint_cast(t1->value()) == jint_cast(t2->value()));
426 }
427 case doubleTag:
428 {
429 DoubleConstant* t1 = type()->as_DoubleConstant();
430 DoubleConstant* t2 = v->type()->as_DoubleConstant();
431 return (t1 != NULL && t2 != NULL &&
432 jlong_cast(t1->value()) == jlong_cast(t2->value()));
433 }
434 case objectTag:
435 {
436 ObjectType* t1 = type()->as_ObjectType();
437 ObjectType* t2 = v->type()->as_ObjectType();
438 return (t1 != NULL && t2 != NULL &&
439 t1->is_loaded() && t2->is_loaded() &&
440 t1->constant_value() == t2->constant_value());
441 }
442 case metaDataTag:
443 {
444 MetadataType* t1 = type()->as_MetadataType();
445 MetadataType* t2 = v->type()->as_MetadataType();
446 return (t1 != NULL && t2 != NULL &&
447 t1->is_loaded() && t2->is_loaded() &&
448 t1->constant_value() == t2->constant_value());
449 }
450 default:
451 return false;
452 }
453 }
454
455 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
456 Constant* rc = right->as_Constant();
457 // other is not a constant
458 if (rc == NULL) return not_comparable;
459
460 ValueType* lt = type();
461 ValueType* rt = rc->type();
462 // different types
463 if (lt->base() != rt->base()) return not_comparable;
464 switch (lt->tag()) {
465 case intTag: {
466 int x = lt->as_IntConstant()->value();
467 int y = rt->as_IntConstant()->value();
468 switch (cond) {
469 case If::eql: return x == y ? cond_true : cond_false;
470 case If::neq: return x != y ? cond_true : cond_false;
471 case If::lss: return x < y ? cond_true : cond_false;
472 case If::leq: return x <= y ? cond_true : cond_false;
473 case If::gtr: return x > y ? cond_true : cond_false;
474 case If::geq: return x >= y ? cond_true : cond_false;
475 default : break;
476 }
477 break;
478 }
479 case longTag: {
480 jlong x = lt->as_LongConstant()->value();
481 jlong y = rt->as_LongConstant()->value();
482 switch (cond) {
483 case If::eql: return x == y ? cond_true : cond_false;
484 case If::neq: return x != y ? cond_true : cond_false;
485 case If::lss: return x < y ? cond_true : cond_false;
486 case If::leq: return x <= y ? cond_true : cond_false;
487 case If::gtr: return x > y ? cond_true : cond_false;
488 case If::geq: return x >= y ? cond_true : cond_false;
489 default : break;
490 }
491 break;
492 }
493 case objectTag: {
494 ciObject* xvalue = lt->as_ObjectType()->constant_value();
495 ciObject* yvalue = rt->as_ObjectType()->constant_value();
496 assert(xvalue != NULL && yvalue != NULL, "not constants");
497 if (xvalue->is_loaded() && yvalue->is_loaded()) {
498 switch (cond) {
499 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
500 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
501 default : break;
502 }
503 }
504 break;
505 }
506 case metaDataTag: {
507 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
508 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
509 assert(xvalue != NULL && yvalue != NULL, "not constants");
510 if (xvalue->is_loaded() && yvalue->is_loaded()) {
511 switch (cond) {
512 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
513 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
514 default : break;
515 }
516 }
517 break;
518 }
519 default:
520 break;
521 }
522 return not_comparable;
523 }
524
525
526 // Implementation of BlockBegin
527
528 void BlockBegin::set_end(BlockEnd* end) {
529 assert(end != NULL, "should not reset block end to NULL");
530 if (end == _end) {
531 return;
532 }
533 clear_end();
534
535 // Set the new end
536 _end = end;
537
538 _successors.clear();
539 // Now reset successors list based on BlockEnd
540 for (int i = 0; i < end->number_of_sux(); i++) {
541 BlockBegin* sux = end->sux_at(i);
542 _successors.append(sux);
543 sux->_predecessors.append(this);
544 }
545 _end->set_begin(this);
546 }
547
548
549 void BlockBegin::clear_end() {
550 // Must make the predecessors/successors match up with the
551 // BlockEnd's notion.
552 if (_end != NULL) {
553 // disconnect from the old end
554 _end->set_begin(NULL);
555
556 // disconnect this block from it's current successors
557 for (int i = 0; i < _successors.length(); i++) {
558 _successors.at(i)->remove_predecessor(this);
559 }
560 _end = NULL;
561 }
562 }
563
564
565 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
566 // disconnect any edges between from and to
567 #ifndef PRODUCT
568 if (PrintIR && Verbose) {
569 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
570 }
571 #endif
572 for (int s = 0; s < from->number_of_sux();) {
573 BlockBegin* sux = from->sux_at(s);
574 if (sux == to) {
575 int index = sux->_predecessors.find(from);
576 if (index >= 0) {
577 sux->_predecessors.remove_at(index);
578 }
579 from->_successors.remove_at(s);
580 } else {
581 s++;
582 }
583 }
584 }
585
586
587 void BlockBegin::disconnect_from_graph() {
588 // disconnect this block from all other blocks
589 for (int p = 0; p < number_of_preds(); p++) {
590 pred_at(p)->remove_successor(this);
591 }
592 for (int s = 0; s < number_of_sux(); s++) {
593 sux_at(s)->remove_predecessor(this);
594 }
595 }
596
597 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
598 // modify predecessors before substituting successors
599 for (int i = 0; i < number_of_sux(); i++) {
600 if (sux_at(i) == old_sux) {
601 // remove old predecessor before adding new predecessor
602 // otherwise there is a dead predecessor in the list
603 new_sux->remove_predecessor(old_sux);
604 new_sux->add_predecessor(this);
605 }
606 }
607 old_sux->remove_predecessor(this);
608 end()->substitute_sux(old_sux, new_sux);
609 }
610
611
612
613 // In general it is not possible to calculate a value for the field "depth_first_number"
614 // of the inserted block, without recomputing the values of the other blocks
615 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
616 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
617 int bci = sux->bci();
618 // critical edge splitting may introduce a goto after a if and array
619 // bound check elimination may insert a predicate between the if and
620 // goto. The bci of the goto can't be the one of the if otherwise
621 // the state and bci are inconsistent and a deoptimization triggered
622 // by the predicate would lead to incorrect execution/a crash.
623 BlockBegin* new_sux = new BlockBegin(bci);
624
625 // mark this block (special treatment when block order is computed)
626 new_sux->set(critical_edge_split_flag);
627
628 // This goto is not a safepoint.
629 Goto* e = new Goto(sux, false);
630 new_sux->set_next(e, bci);
631 new_sux->set_end(e);
632 // setup states
633 ValueStack* s = end()->state();
634 new_sux->set_state(s->copy(s->kind(), bci));
635 e->set_state(s->copy(s->kind(), bci));
636 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
637 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
638 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
639
640 // link predecessor to new block
641 end()->substitute_sux(sux, new_sux);
642
643 // The ordering needs to be the same, so remove the link that the
644 // set_end call above added and substitute the new_sux for this
645 // block.
646 sux->remove_predecessor(new_sux);
647
648 // the successor could be the target of a switch so it might have
649 // multiple copies of this predecessor, so substitute the new_sux
650 // for the first and delete the rest.
651 bool assigned = false;
652 BlockList& list = sux->_predecessors;
653 for (int i = 0; i < list.length(); i++) {
654 BlockBegin** b = list.adr_at(i);
655 if (*b == this) {
656 if (assigned) {
657 list.remove_at(i);
658 // reprocess this index
659 i--;
660 } else {
661 assigned = true;
662 *b = new_sux;
663 }
664 // link the new block back to it's predecessors.
665 new_sux->add_predecessor(this);
666 }
667 }
668 assert(assigned == true, "should have assigned at least once");
669 return new_sux;
670 }
671
672
673 void BlockBegin::remove_successor(BlockBegin* pred) {
674 int idx;
675 while ((idx = _successors.find(pred)) >= 0) {
676 _successors.remove_at(idx);
677 }
678 }
679
680
681 void BlockBegin::add_predecessor(BlockBegin* pred) {
682 _predecessors.append(pred);
683 }
684
685
686 void BlockBegin::remove_predecessor(BlockBegin* pred) {
687 int idx;
688 while ((idx = _predecessors.find(pred)) >= 0) {
689 _predecessors.remove_at(idx);
690 }
691 }
692
693
694 void BlockBegin::add_exception_handler(BlockBegin* b) {
695 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
696 // add only if not in the list already
697 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
698 }
699
700 int BlockBegin::add_exception_state(ValueStack* state) {
701 assert(is_set(exception_entry_flag), "only for xhandlers");
702 if (_exception_states == NULL) {
703 _exception_states = new ValueStackStack(4);
704 }
705 _exception_states->append(state);
706 return _exception_states->length() - 1;
707 }
708
709
710 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
711 if (!mark.at(block_id())) {
712 mark.at_put(block_id(), true);
713 closure->block_do(this);
714 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
715 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
716 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
717 }
718 }
719
720
721 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
722 if (!mark.at(block_id())) {
723 mark.at_put(block_id(), true);
724 BlockEnd* e = end();
725 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
726 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
727 closure->block_do(this);
728 }
729 }
730
731
732 void BlockBegin::iterate_preorder(BlockClosure* closure) {
733 int mark_len = number_of_blocks();
734 boolArray mark(mark_len, mark_len, false);
735 iterate_preorder(mark, closure);
736 }
737
738
739 void BlockBegin::iterate_postorder(BlockClosure* closure) {
740 int mark_len = number_of_blocks();
741 boolArray mark(mark_len, mark_len, false);
742 iterate_postorder(mark, closure);
743 }
744
745
746 void BlockBegin::block_values_do(ValueVisitor* f) {
747 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
748 }
749
750
751 #ifndef PRODUCT
752 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
753 #else
754 #define TRACE_PHI(coce)
755 #endif
756
757
758 bool BlockBegin::try_merge(ValueStack* new_state) {
759 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
760
761 // local variables used for state iteration
762 int index;
763 Value new_value, existing_value;
764
765 ValueStack* existing_state = state();
766 if (existing_state == NULL) {
767 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
768
769 if (is_set(BlockBegin::was_visited_flag)) {
770 // this actually happens for complicated jsr/ret structures
771 return false; // BAILOUT in caller
772 }
773
774 // copy state because it is altered
775 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
776
777 // Use method liveness to invalidate dead locals
778 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
779 if (liveness.is_valid()) {
780 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
781
782 for_each_local_value(new_state, index, new_value) {
783 if (!liveness.at(index) || new_value->type()->is_illegal()) {
784 new_state->invalidate_local(index);
785 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
786 }
787 }
788 }
789
790 if (is_set(BlockBegin::parser_loop_header_flag)) {
791 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
792
793 for_each_stack_value(new_state, index, new_value) {
794 new_state->setup_phi_for_stack(this, index);
795 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));
796 }
797
798 BitMap& requires_phi_function = new_state->scope()->requires_phi_function();
799
800 for_each_local_value(new_state, index, new_value) {
801 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
802 if (requires_phi || !SelectivePhiFunctions) {
803 new_state->setup_phi_for_local(this, index);
804 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));
805 }
806 }
807 }
808
809 // initialize state of block
810 set_state(new_state);
811
812 } else if (existing_state->is_same(new_state)) {
813 TRACE_PHI(tty->print_cr("exisiting state found"));
814
815 assert(existing_state->scope() == new_state->scope(), "not matching");
816 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
817 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
818
819 if (is_set(BlockBegin::was_visited_flag)) {
820 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
821
822 if (!is_set(BlockBegin::parser_loop_header_flag)) {
823 // this actually happens for complicated jsr/ret structures
824 return false; // BAILOUT in caller
825 }
826
827 for_each_local_value(existing_state, index, existing_value) {
828 Value new_value = new_state->local_at(index);
829 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
830 Phi* existing_phi = existing_value->as_Phi();
831 if (existing_phi == NULL) {
832 return false; // BAILOUT in caller
833 }
834 // Invalidate the phi function here. This case is very rare except for
835 // JVMTI capability "can_access_local_variables".
836 // In really rare cases we will bail out in LIRGenerator::move_to_phi.
837 existing_phi->make_illegal();
838 existing_state->invalidate_local(index);
839 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
840 }
841 }
842
843 #ifdef ASSERT
844 // check that all necessary phi functions are present
845 for_each_stack_value(existing_state, index, existing_value) {
846 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
847 }
848 for_each_local_value(existing_state, index, existing_value) {
849 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
850 }
851 #endif
852
853 } else {
854 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
855
856 // create necessary phi functions for stack
857 for_each_stack_value(existing_state, index, existing_value) {
858 Value new_value = new_state->stack_at(index);
859 Phi* existing_phi = existing_value->as_Phi();
860
861 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
862 existing_state->setup_phi_for_stack(this, index);
863 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));
864 }
865 }
866
867 // create necessary phi functions for locals
868 for_each_local_value(existing_state, index, existing_value) {
869 Value new_value = new_state->local_at(index);
870 Phi* existing_phi = existing_value->as_Phi();
871
872 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
873 existing_state->invalidate_local(index);
874 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
875 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
876 existing_state->setup_phi_for_local(this, index);
877 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));
878 }
879 }
880 }
881
882 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
883
884 } else {
885 assert(false, "stack or locks not matching (invalid bytecodes)");
886 return false;
887 }
888
889 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
890
891 return true;
892 }
893
894
895 #ifndef PRODUCT
896 void BlockBegin::print_block() {
897 InstructionPrinter ip;
898 print_block(ip, false);
899 }
900
901
902 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
903 ip.print_instr(this); tty->cr();
904 ip.print_stack(this->state()); tty->cr();
905 ip.print_inline_level(this);
906 ip.print_head();
907 for (Instruction* n = next(); n != NULL; n = n->next()) {
908 if (!live_only || n->is_pinned() || n->use_count() > 0) {
909 ip.print_line(n);
910 }
911 }
912 tty->cr();
913 }
914 #endif // PRODUCT
915
916
917 // Implementation of BlockList
918
919 void BlockList::iterate_forward (BlockClosure* closure) {
920 const int l = length();
921 for (int i = 0; i < l; i++) closure->block_do(at(i));
922 }
923
924
925 void BlockList::iterate_backward(BlockClosure* closure) {
926 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
927 }
928
929
930 void BlockList::blocks_do(void f(BlockBegin*)) {
931 for (int i = length() - 1; i >= 0; i--) f(at(i));
932 }
933
934
935 void BlockList::values_do(ValueVisitor* f) {
936 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
937 }
938
939
940 #ifndef PRODUCT
941 void BlockList::print(bool cfg_only, bool live_only) {
942 InstructionPrinter ip;
943 for (int i = 0; i < length(); i++) {
944 BlockBegin* block = at(i);
945 if (cfg_only) {
946 ip.print_instr(block); tty->cr();
947 } else {
948 block->print_block(ip, live_only);
949 }
950 }
951 }
952 #endif // PRODUCT
953
954
955 // Implementation of BlockEnd
956
957 void BlockEnd::set_begin(BlockBegin* begin) {
958 BlockList* sux = NULL;
959 if (begin != NULL) {
960 sux = begin->successors();
961 } else if (this->begin() != NULL) {
962 // copy our sux list
963 BlockList* sux = new BlockList(this->begin()->number_of_sux());
964 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
965 sux->append(this->begin()->sux_at(i));
966 }
967 }
968 _sux = sux;
969 }
970
971
972 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
973 substitute(*_sux, old_sux, new_sux);
974 }
975
976
977 // Implementation of Phi
978
979 // Normal phi functions take their operands from the last instruction of the
980 // predecessor. Special handling is needed for xhanlder entries because there
981 // the state of arbitrary instructions are needed.
982
983 Value Phi::operand_at(int i) const {
984 ValueStack* state;
985 if (_block->is_set(BlockBegin::exception_entry_flag)) {
986 state = _block->exception_state_at(i);
987 } else {
988 state = _block->pred_at(i)->end()->state();
989 }
990 assert(state != NULL, "");
991
992 if (is_local()) {
993 return state->local_at(local_index());
994 } else {
995 return state->stack_at(stack_index());
996 }
997 }
998
999
1000 int Phi::operand_count() const {
1001 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1002 return _block->number_of_exception_states();
1003 } else {
1004 return _block->number_of_preds();
1005 }
1006 }
1007
1008 #ifdef ASSERT
1009 // Constructor of Assert
1010 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
1011 , _x(x)
1012 , _cond(cond)
1013 , _y(y)
1014 {
1015 set_flag(UnorderedIsTrueFlag, unordered_is_true);
1016 assert(x->type()->tag() == y->type()->tag(), "types must match");
1017 pin();
1018
1019 stringStream strStream;
1020 Compilation::current()->method()->print_name(&strStream);
1021
1022 stringStream strStream1;
1023 InstructionPrinter ip1(1, &strStream1);
1024 ip1.print_instr(x);
1025
1026 stringStream strStream2;
1027 InstructionPrinter ip2(1, &strStream2);
1028 ip2.print_instr(y);
1029
1030 stringStream ss;
1031 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1032
1033 _message = ss.as_string();
1034 }
1035 #endif
1036
1037 void RangeCheckPredicate::check_state() {
1038 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1039 }
1040
1041 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1042 if (state() != NULL) state()->values_do(f);
1043 }