1 /*
2 * Copyright (c) 1999, 2019, 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
118 // FIXME -- this is used by ValueStack::merge_types only. We should remove this function
119 // and use a better way for handling phi nodes.
120 bool Instruction::is_flattened_array() const {
121 if (ValueArrayFlatten) {
122 ciType* type = declared_type();
123 if (type != NULL && type->is_value_array_klass()) {
124 ciValueKlass* element_klass = type->as_value_array_klass()->element_klass()->as_value_klass();
125 assert(element_klass->is_loaded(), "ciValueKlasses are always loaded");
126 if (element_klass->flatten_array()) {
127 return true;
128 }
129 }
130 }
131
132 return false;
133 }
134
135 bool Instruction::is_loaded_flattened_array() const {
136 if (ValueArrayFlatten) {
137 ciType* type = declared_type();
138 if (type != NULL && type->is_value_array_klass()) {
139 ciValueKlass* element_klass = type->as_value_array_klass()->element_klass()->as_value_klass();
140 assert(element_klass->is_loaded(), "ciValueKlasses are always loaded");
141 if (element_klass->flatten_array()) {
142 return true;
143 }
144 }
145 }
146
147 return false;
148 }
149
150 bool Instruction::maybe_flattened_array() {
151 if (ValueArrayFlatten) {
152 ciType* type = declared_type();
153 if (type != NULL) {
154 if (type->is_value_array_klass()) {
155 ciValueKlass* element_klass = type->as_value_array_klass()->element_klass()->as_value_klass();
156 assert(element_klass->is_loaded(), "ciValueKlasses are always loaded");
157 if (element_klass->flatten_array()) {
158 return true;
159 }
160 } else if (type->is_obj_array_klass()) {
161 ciKlass* element_klass = type->as_obj_array_klass()->element_klass();
162 if (!element_klass->is_loaded() || element_klass->is_java_lang_Object() || element_klass->is_interface()) {
163 // Array covariance:
164 // (ValueType[] <: Object[])
165 // (ValueType[] <: <any interface>[])
166 // We will add a runtime check for flat-ness.
167 return true;
168 }
169 } else if (type->is_klass() && type->as_klass()->is_java_lang_Object()) {
170 // This can happen as a parameter to System.arraycopy()
171 return true;
172 }
173 } else if (as_Phi() != NULL) {
174 // Type info gets lost during Phi merging, but we might be storing into a
175 // flattened array, so we should do a runtime check.
176 return true;
177 }
178 }
179
180 return false;
181 }
182
183 #ifndef PRODUCT
184 void Instruction::check_state(ValueStack* state) {
185 if (state != NULL) {
186 state->verify();
187 }
188 }
189
190
191 void Instruction::print() {
192 InstructionPrinter ip;
193 print(ip);
194 }
195
196
197 void Instruction::print_line() {
198 InstructionPrinter ip;
199 ip.print_line(this);
200 }
201
202
203 void Instruction::print(InstructionPrinter& ip) {
204 ip.print_head();
205 ip.print_line(this);
206 tty->cr();
207 }
208 #endif // PRODUCT
209
210
211 // perform constant and interval tests on index value
212 bool AccessIndexed::compute_needs_range_check() {
213 if (length()) {
214 Constant* clength = length()->as_Constant();
215 Constant* cindex = index()->as_Constant();
216 if (clength && cindex) {
217 IntConstant* l = clength->type()->as_IntConstant();
218 IntConstant* i = cindex->type()->as_IntConstant();
219 if (l && i && i->value() < l->value() && i->value() >= 0) {
220 return false;
221 }
222 }
223 }
224
225 if (!this->check_flag(NeedsRangeCheckFlag)) {
226 return false;
227 }
228
229 return true;
230 }
231
232
233 ciType* Constant::exact_type() const {
234 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) {
235 return type()->as_ObjectType()->exact_type();
236 }
237 return NULL;
238 }
239
240 ciType* LoadIndexed::exact_type() const {
241 ciType* array_type = array()->exact_type();
242 if (array_type != NULL) {
243 assert(array_type->is_array_klass(), "what else?");
244 ciArrayKlass* ak = (ciArrayKlass*)array_type;
245
246 if (ak->element_type()->is_instance_klass()) {
247 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type();
248 if (ik->is_loaded() && ik->is_final()) {
249 return ik;
250 }
251 }
252 }
253 return Instruction::exact_type();
254 }
255
256
257 ciType* LoadIndexed::declared_type() const {
258 ciType* array_type = array()->declared_type();
259 if (array_type == NULL || !array_type->is_loaded()) {
260 return NULL;
261 }
262 assert(array_type->is_array_klass(), "what else?");
263 ciArrayKlass* ak = (ciArrayKlass*)array_type;
264 return ak->element_type();
265 }
266
267 bool StoreIndexed::is_exact_flattened_array_store() const {
268 if (array()->is_loaded_flattened_array() && value()->as_Constant() == NULL) {
269 ciKlass* element_klass = array()->declared_type()->as_value_array_klass()->element_klass();
270 ciKlass* actual_klass = value()->declared_type()->as_klass();
271 if (element_klass == actual_klass) {
272 return true;
273 }
274 }
275 return false;
276 }
277
278 ciType* LoadField::declared_type() const {
279 return field()->type();
280 }
281
282
283 ciType* NewTypeArray::exact_type() const {
284 return ciTypeArrayKlass::make(elt_type());
285 }
286
287 ciType* NewObjectArray::exact_type() const {
288 ciKlass* element_klass = klass();
289 if (element_klass->is_valuetype()) {
290 return ciValueArrayKlass::make(element_klass);
291 } else {
292 return ciObjArrayKlass::make(element_klass);
293 }
294 }
295
296 ciType* NewMultiArray::exact_type() const {
297 return _klass;
298 }
299
300 ciType* NewArray::declared_type() const {
301 return exact_type();
302 }
303
304 ciType* NewInstance::exact_type() const {
305 return klass();
306 }
307
308 ciType* NewInstance::declared_type() const {
309 return exact_type();
310 }
311
312 Value NewValueTypeInstance::depends_on() {
313 if (_depends_on != this) {
314 if (_depends_on->as_NewValueTypeInstance() != NULL) {
315 return _depends_on->as_NewValueTypeInstance()->depends_on();
316 }
317 }
318 return _depends_on;
319 }
320
321 ciType* NewValueTypeInstance::exact_type() const {
322 return klass();
323 }
324
325 ciType* NewValueTypeInstance::declared_type() const {
326 return exact_type();
327 }
328
329 ciType* CheckCast::declared_type() const {
330 return klass();
331 }
332
333 // Implementation of ArithmeticOp
334
335 bool ArithmeticOp::is_commutative() const {
336 switch (op()) {
337 case Bytecodes::_iadd: // fall through
338 case Bytecodes::_ladd: // fall through
339 case Bytecodes::_fadd: // fall through
340 case Bytecodes::_dadd: // fall through
341 case Bytecodes::_imul: // fall through
342 case Bytecodes::_lmul: // fall through
343 case Bytecodes::_fmul: // fall through
344 case Bytecodes::_dmul: return true;
345 default : return false;
346 }
347 }
348
349
350 bool ArithmeticOp::can_trap() const {
351 switch (op()) {
352 case Bytecodes::_idiv: // fall through
353 case Bytecodes::_ldiv: // fall through
354 case Bytecodes::_irem: // fall through
355 case Bytecodes::_lrem: return true;
356 default : return false;
357 }
358 }
359
360
361 // Implementation of LogicOp
362
363 bool LogicOp::is_commutative() const {
364 #ifdef ASSERT
365 switch (op()) {
366 case Bytecodes::_iand: // fall through
367 case Bytecodes::_land: // fall through
368 case Bytecodes::_ior : // fall through
369 case Bytecodes::_lor : // fall through
370 case Bytecodes::_ixor: // fall through
371 case Bytecodes::_lxor: break;
372 default : ShouldNotReachHere(); break;
373 }
374 #endif
375 // all LogicOps are commutative
376 return true;
377 }
378
379
380 // Implementation of IfOp
381
382 bool IfOp::is_commutative() const {
383 return cond() == eql || cond() == neq;
384 }
385
386
387 // Implementation of StateSplit
388
389 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) {
390 NOT_PRODUCT(bool assigned = false;)
391 for (int i = 0; i < list.length(); i++) {
392 BlockBegin** b = list.adr_at(i);
393 if (*b == old_block) {
394 *b = new_block;
395 NOT_PRODUCT(assigned = true;)
396 }
397 }
398 assert(assigned == true, "should have assigned at least once");
399 }
400
401
402 IRScope* StateSplit::scope() const {
403 return _state->scope();
404 }
405
406
407 void StateSplit::state_values_do(ValueVisitor* f) {
408 Instruction::state_values_do(f);
409 if (state() != NULL) state()->values_do(f);
410 }
411
412
413 void BlockBegin::state_values_do(ValueVisitor* f) {
414 StateSplit::state_values_do(f);
415
416 if (is_set(BlockBegin::exception_entry_flag)) {
417 for (int i = 0; i < number_of_exception_states(); i++) {
418 exception_state_at(i)->values_do(f);
419 }
420 }
421 }
422
423
424 // Implementation of Invoke
425
426
427 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args,
428 int vtable_index, ciMethod* target, ValueStack* state_before, bool never_null)
429 : StateSplit(result_type, state_before)
430 , _code(code)
431 , _recv(recv)
432 , _args(args)
433 , _vtable_index(vtable_index)
434 , _target(target)
435 {
436 set_flag(TargetIsLoadedFlag, target->is_loaded());
437 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method());
438 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict());
439 set_never_null(never_null);
440
441 assert(args != NULL, "args must exist");
442 #ifdef ASSERT
443 AssertValues assert_value;
444 values_do(&assert_value);
445 #endif
446
447 // provide an initial guess of signature size.
448 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0));
449 if (has_receiver()) {
450 _signature->append(as_BasicType(receiver()->type()));
451 }
452 for (int i = 0; i < number_of_arguments(); i++) {
453 ValueType* t = argument_at(i)->type();
454 BasicType bt = as_BasicType(t);
455 _signature->append(bt);
456 }
457 }
458
459
460 void Invoke::state_values_do(ValueVisitor* f) {
461 StateSplit::state_values_do(f);
462 if (state_before() != NULL) state_before()->values_do(f);
463 if (state() != NULL) state()->values_do(f);
464 }
465
466 ciType* Invoke::declared_type() const {
467 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci());
468 ciType *t = declared_signature->return_type();
469 assert(t->basic_type() != T_VOID, "need return value of void method?");
470 return t;
471 }
472
473 // Implementation of Contant
474 intx Constant::hash() const {
475 if (state_before() == NULL) {
476 switch (type()->tag()) {
477 case intTag:
478 return HASH2(name(), type()->as_IntConstant()->value());
479 case addressTag:
480 return HASH2(name(), type()->as_AddressConstant()->value());
481 case longTag:
482 {
483 jlong temp = type()->as_LongConstant()->value();
484 return HASH3(name(), high(temp), low(temp));
485 }
486 case floatTag:
487 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value()));
488 case doubleTag:
489 {
490 jlong temp = jlong_cast(type()->as_DoubleConstant()->value());
491 return HASH3(name(), high(temp), low(temp));
492 }
493 case objectTag:
494 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values");
495 return HASH2(name(), type()->as_ObjectType()->constant_value());
496 case metaDataTag:
497 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values");
498 return HASH2(name(), type()->as_MetadataType()->constant_value());
499 default:
500 ShouldNotReachHere();
501 }
502 }
503 return 0;
504 }
505
506 bool Constant::is_equal(Value v) const {
507 if (v->as_Constant() == NULL) return false;
508
509 switch (type()->tag()) {
510 case intTag:
511 {
512 IntConstant* t1 = type()->as_IntConstant();
513 IntConstant* t2 = v->type()->as_IntConstant();
514 return (t1 != NULL && t2 != NULL &&
515 t1->value() == t2->value());
516 }
517 case longTag:
518 {
519 LongConstant* t1 = type()->as_LongConstant();
520 LongConstant* t2 = v->type()->as_LongConstant();
521 return (t1 != NULL && t2 != NULL &&
522 t1->value() == t2->value());
523 }
524 case floatTag:
525 {
526 FloatConstant* t1 = type()->as_FloatConstant();
527 FloatConstant* t2 = v->type()->as_FloatConstant();
528 return (t1 != NULL && t2 != NULL &&
529 jint_cast(t1->value()) == jint_cast(t2->value()));
530 }
531 case doubleTag:
532 {
533 DoubleConstant* t1 = type()->as_DoubleConstant();
534 DoubleConstant* t2 = v->type()->as_DoubleConstant();
535 return (t1 != NULL && t2 != NULL &&
536 jlong_cast(t1->value()) == jlong_cast(t2->value()));
537 }
538 case objectTag:
539 {
540 ObjectType* t1 = type()->as_ObjectType();
541 ObjectType* t2 = v->type()->as_ObjectType();
542 return (t1 != NULL && t2 != NULL &&
543 t1->is_loaded() && t2->is_loaded() &&
544 t1->constant_value() == t2->constant_value());
545 }
546 case metaDataTag:
547 {
548 MetadataType* t1 = type()->as_MetadataType();
549 MetadataType* t2 = v->type()->as_MetadataType();
550 return (t1 != NULL && t2 != NULL &&
551 t1->is_loaded() && t2->is_loaded() &&
552 t1->constant_value() == t2->constant_value());
553 }
554 default:
555 return false;
556 }
557 }
558
559 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const {
560 Constant* rc = right->as_Constant();
561 // other is not a constant
562 if (rc == NULL) return not_comparable;
563
564 ValueType* lt = type();
565 ValueType* rt = rc->type();
566 // different types
567 if (lt->base() != rt->base()) return not_comparable;
568 switch (lt->tag()) {
569 case intTag: {
570 int x = lt->as_IntConstant()->value();
571 int y = rt->as_IntConstant()->value();
572 switch (cond) {
573 case If::eql: return x == y ? cond_true : cond_false;
574 case If::neq: return x != y ? cond_true : cond_false;
575 case If::lss: return x < y ? cond_true : cond_false;
576 case If::leq: return x <= y ? cond_true : cond_false;
577 case If::gtr: return x > y ? cond_true : cond_false;
578 case If::geq: return x >= y ? cond_true : cond_false;
579 default : break;
580 }
581 break;
582 }
583 case longTag: {
584 jlong x = lt->as_LongConstant()->value();
585 jlong y = rt->as_LongConstant()->value();
586 switch (cond) {
587 case If::eql: return x == y ? cond_true : cond_false;
588 case If::neq: return x != y ? cond_true : cond_false;
589 case If::lss: return x < y ? cond_true : cond_false;
590 case If::leq: return x <= y ? cond_true : cond_false;
591 case If::gtr: return x > y ? cond_true : cond_false;
592 case If::geq: return x >= y ? cond_true : cond_false;
593 default : break;
594 }
595 break;
596 }
597 case objectTag: {
598 ciObject* xvalue = lt->as_ObjectType()->constant_value();
599 ciObject* yvalue = rt->as_ObjectType()->constant_value();
600 assert(xvalue != NULL && yvalue != NULL, "not constants");
601 if (xvalue->is_loaded() && yvalue->is_loaded()) {
602 switch (cond) {
603 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
604 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
605 default : break;
606 }
607 }
608 break;
609 }
610 case metaDataTag: {
611 ciMetadata* xvalue = lt->as_MetadataType()->constant_value();
612 ciMetadata* yvalue = rt->as_MetadataType()->constant_value();
613 assert(xvalue != NULL && yvalue != NULL, "not constants");
614 if (xvalue->is_loaded() && yvalue->is_loaded()) {
615 switch (cond) {
616 case If::eql: return xvalue == yvalue ? cond_true : cond_false;
617 case If::neq: return xvalue != yvalue ? cond_true : cond_false;
618 default : break;
619 }
620 }
621 break;
622 }
623 default:
624 break;
625 }
626 return not_comparable;
627 }
628
629
630 // Implementation of BlockBegin
631
632 void BlockBegin::set_end(BlockEnd* end) {
633 assert(end != NULL, "should not reset block end to NULL");
634 if (end == _end) {
635 return;
636 }
637 clear_end();
638
639 // Set the new end
640 _end = end;
641
642 _successors.clear();
643 // Now reset successors list based on BlockEnd
644 for (int i = 0; i < end->number_of_sux(); i++) {
645 BlockBegin* sux = end->sux_at(i);
646 _successors.append(sux);
647 sux->_predecessors.append(this);
648 }
649 _end->set_begin(this);
650 }
651
652
653 void BlockBegin::clear_end() {
654 // Must make the predecessors/successors match up with the
655 // BlockEnd's notion.
656 if (_end != NULL) {
657 // disconnect from the old end
658 _end->set_begin(NULL);
659
660 // disconnect this block from it's current successors
661 for (int i = 0; i < _successors.length(); i++) {
662 _successors.at(i)->remove_predecessor(this);
663 }
664 _end = NULL;
665 }
666 }
667
668
669 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) {
670 // disconnect any edges between from and to
671 #ifndef PRODUCT
672 if (PrintIR && Verbose) {
673 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id());
674 }
675 #endif
676 for (int s = 0; s < from->number_of_sux();) {
677 BlockBegin* sux = from->sux_at(s);
678 if (sux == to) {
679 int index = sux->_predecessors.find(from);
680 if (index >= 0) {
681 sux->_predecessors.remove_at(index);
682 }
683 from->_successors.remove_at(s);
684 } else {
685 s++;
686 }
687 }
688 }
689
690
691 void BlockBegin::disconnect_from_graph() {
692 // disconnect this block from all other blocks
693 for (int p = 0; p < number_of_preds(); p++) {
694 pred_at(p)->remove_successor(this);
695 }
696 for (int s = 0; s < number_of_sux(); s++) {
697 sux_at(s)->remove_predecessor(this);
698 }
699 }
700
701 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
702 // modify predecessors before substituting successors
703 for (int i = 0; i < number_of_sux(); i++) {
704 if (sux_at(i) == old_sux) {
705 // remove old predecessor before adding new predecessor
706 // otherwise there is a dead predecessor in the list
707 new_sux->remove_predecessor(old_sux);
708 new_sux->add_predecessor(this);
709 }
710 }
711 old_sux->remove_predecessor(this);
712 end()->substitute_sux(old_sux, new_sux);
713 }
714
715
716
717 // In general it is not possible to calculate a value for the field "depth_first_number"
718 // of the inserted block, without recomputing the values of the other blocks
719 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless.
720 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) {
721 int bci = sux->bci();
722 // critical edge splitting may introduce a goto after a if and array
723 // bound check elimination may insert a predicate between the if and
724 // goto. The bci of the goto can't be the one of the if otherwise
725 // the state and bci are inconsistent and a deoptimization triggered
726 // by the predicate would lead to incorrect execution/a crash.
727 BlockBegin* new_sux = new BlockBegin(bci);
728
729 // mark this block (special treatment when block order is computed)
730 new_sux->set(critical_edge_split_flag);
731
732 // This goto is not a safepoint.
733 Goto* e = new Goto(sux, false);
734 new_sux->set_next(e, bci);
735 new_sux->set_end(e);
736 // setup states
737 ValueStack* s = end()->state();
738 new_sux->set_state(s->copy(s->kind(), bci));
739 e->set_state(s->copy(s->kind(), bci));
740 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!");
741 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!");
742 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!");
743
744 // link predecessor to new block
745 end()->substitute_sux(sux, new_sux);
746
747 // The ordering needs to be the same, so remove the link that the
748 // set_end call above added and substitute the new_sux for this
749 // block.
750 sux->remove_predecessor(new_sux);
751
752 // the successor could be the target of a switch so it might have
753 // multiple copies of this predecessor, so substitute the new_sux
754 // for the first and delete the rest.
755 bool assigned = false;
756 BlockList& list = sux->_predecessors;
757 for (int i = 0; i < list.length(); i++) {
758 BlockBegin** b = list.adr_at(i);
759 if (*b == this) {
760 if (assigned) {
761 list.remove_at(i);
762 // reprocess this index
763 i--;
764 } else {
765 assigned = true;
766 *b = new_sux;
767 }
768 // link the new block back to it's predecessors.
769 new_sux->add_predecessor(this);
770 }
771 }
772 assert(assigned == true, "should have assigned at least once");
773 return new_sux;
774 }
775
776
777 void BlockBegin::remove_successor(BlockBegin* pred) {
778 int idx;
779 while ((idx = _successors.find(pred)) >= 0) {
780 _successors.remove_at(idx);
781 }
782 }
783
784
785 void BlockBegin::add_predecessor(BlockBegin* pred) {
786 _predecessors.append(pred);
787 }
788
789
790 void BlockBegin::remove_predecessor(BlockBegin* pred) {
791 int idx;
792 while ((idx = _predecessors.find(pred)) >= 0) {
793 _predecessors.remove_at(idx);
794 }
795 }
796
797
798 void BlockBegin::add_exception_handler(BlockBegin* b) {
799 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist");
800 // add only if not in the list already
801 if (!_exception_handlers.contains(b)) _exception_handlers.append(b);
802 }
803
804 int BlockBegin::add_exception_state(ValueStack* state) {
805 assert(is_set(exception_entry_flag), "only for xhandlers");
806 if (_exception_states == NULL) {
807 _exception_states = new ValueStackStack(4);
808 }
809 _exception_states->append(state);
810 return _exception_states->length() - 1;
811 }
812
813
814 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) {
815 if (!mark.at(block_id())) {
816 mark.at_put(block_id(), true);
817 closure->block_do(this);
818 BlockEnd* e = end(); // must do this after block_do because block_do may change it!
819 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); }
820 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); }
821 }
822 }
823
824
825 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) {
826 if (!mark.at(block_id())) {
827 mark.at_put(block_id(), true);
828 BlockEnd* e = end();
829 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); }
830 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); }
831 closure->block_do(this);
832 }
833 }
834
835
836 void BlockBegin::iterate_preorder(BlockClosure* closure) {
837 int mark_len = number_of_blocks();
838 boolArray mark(mark_len, mark_len, false);
839 iterate_preorder(mark, closure);
840 }
841
842
843 void BlockBegin::iterate_postorder(BlockClosure* closure) {
844 int mark_len = number_of_blocks();
845 boolArray mark(mark_len, mark_len, false);
846 iterate_postorder(mark, closure);
847 }
848
849
850 void BlockBegin::block_values_do(ValueVisitor* f) {
851 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f);
852 }
853
854
855 #ifndef PRODUCT
856 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; }
857 #else
858 #define TRACE_PHI(coce)
859 #endif
860
861
862 bool BlockBegin::try_merge(ValueStack* new_state) {
863 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id()));
864
865 // local variables used for state iteration
866 int index;
867 Value new_value, existing_value;
868
869 ValueStack* existing_state = state();
870 if (existing_state == NULL) {
871 TRACE_PHI(tty->print_cr("first call of try_merge for this block"));
872
873 if (is_set(BlockBegin::was_visited_flag)) {
874 // this actually happens for complicated jsr/ret structures
875 return false; // BAILOUT in caller
876 }
877
878 // copy state because it is altered
879 new_state = new_state->copy(ValueStack::BlockBeginState, bci());
880
881 // Use method liveness to invalidate dead locals
882 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci());
883 if (liveness.is_valid()) {
884 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness");
885
886 for_each_local_value(new_state, index, new_value) {
887 if (!liveness.at(index) || new_value->type()->is_illegal()) {
888 new_state->invalidate_local(index);
889 TRACE_PHI(tty->print_cr("invalidating dead local %d", index));
890 }
891 }
892 }
893
894 if (is_set(BlockBegin::parser_loop_header_flag)) {
895 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions"));
896
897 for_each_stack_value(new_state, index, new_value) {
898 new_state->setup_phi_for_stack(this, index, NULL, new_value);
899 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));
900 }
901
902 BitMap& requires_phi_function = new_state->scope()->requires_phi_function();
903
904 for_each_local_value(new_state, index, new_value) {
905 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1));
906 if (requires_phi || !SelectivePhiFunctions) {
907 new_state->setup_phi_for_local(this, index, NULL, new_value);
908 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));
909 }
910 }
911 }
912
913 // initialize state of block
914 set_state(new_state);
915
916 } else if (existing_state->is_same(new_state)) {
917 TRACE_PHI(tty->print_cr("exisiting state found"));
918
919 assert(existing_state->scope() == new_state->scope(), "not matching");
920 assert(existing_state->locals_size() == new_state->locals_size(), "not matching");
921 assert(existing_state->stack_size() == new_state->stack_size(), "not matching");
922
923 if (is_set(BlockBegin::was_visited_flag)) {
924 TRACE_PHI(tty->print_cr("loop header block, phis must be present"));
925
926 if (!is_set(BlockBegin::parser_loop_header_flag)) {
927 // this actually happens for complicated jsr/ret structures
928 return false; // BAILOUT in caller
929 }
930
931 for_each_local_value(existing_state, index, existing_value) {
932 Value new_value = new_state->local_at(index);
933 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
934 Phi* existing_phi = existing_value->as_Phi();
935 if (existing_phi == NULL) {
936 return false; // BAILOUT in caller
937 }
938 // Invalidate the phi function here. This case is very rare except for
939 // JVMTI capability "can_access_local_variables".
940 // In really rare cases we will bail out in LIRGenerator::move_to_phi.
941 existing_phi->make_illegal();
942 existing_state->invalidate_local(index);
943 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
944 }
945 }
946
947 #ifdef ASSERT
948 // check that all necessary phi functions are present
949 for_each_stack_value(existing_state, index, existing_value) {
950 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required");
951 }
952 for_each_local_value(existing_state, index, existing_value) {
953 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required");
954 }
955 #endif
956
957 } else {
958 TRACE_PHI(tty->print_cr("creating phi functions on demand"));
959
960 // create necessary phi functions for stack
961 for_each_stack_value(existing_state, index, existing_value) {
962 Value new_value = new_state->stack_at(index);
963 Phi* existing_phi = existing_value->as_Phi();
964
965 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
966 existing_state->setup_phi_for_stack(this, index, existing_value, new_value);
967 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));
968 }
969 }
970
971 // create necessary phi functions for locals
972 for_each_local_value(existing_state, index, existing_value) {
973 Value new_value = new_state->local_at(index);
974 Phi* existing_phi = existing_value->as_Phi();
975
976 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) {
977 existing_state->invalidate_local(index);
978 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index));
979 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) {
980 existing_state->setup_phi_for_local(this, index, existing_value, new_value);
981 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));
982 }
983 }
984 }
985
986 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal");
987
988 } else {
989 assert(false, "stack or locks not matching (invalid bytecodes)");
990 return false;
991 }
992
993 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id()));
994
995 return true;
996 }
997
998
999 #ifndef PRODUCT
1000 void BlockBegin::print_block() {
1001 InstructionPrinter ip;
1002 print_block(ip, false);
1003 }
1004
1005
1006 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) {
1007 ip.print_instr(this); tty->cr();
1008 ip.print_stack(this->state()); tty->cr();
1009 ip.print_inline_level(this);
1010 ip.print_head();
1011 for (Instruction* n = next(); n != NULL; n = n->next()) {
1012 if (!live_only || n->is_pinned() || n->use_count() > 0) {
1013 ip.print_line(n);
1014 }
1015 }
1016 tty->cr();
1017 }
1018 #endif // PRODUCT
1019
1020
1021 // Implementation of BlockList
1022
1023 void BlockList::iterate_forward (BlockClosure* closure) {
1024 const int l = length();
1025 for (int i = 0; i < l; i++) closure->block_do(at(i));
1026 }
1027
1028
1029 void BlockList::iterate_backward(BlockClosure* closure) {
1030 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i));
1031 }
1032
1033
1034 void BlockList::blocks_do(void f(BlockBegin*)) {
1035 for (int i = length() - 1; i >= 0; i--) f(at(i));
1036 }
1037
1038
1039 void BlockList::values_do(ValueVisitor* f) {
1040 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f);
1041 }
1042
1043
1044 #ifndef PRODUCT
1045 void BlockList::print(bool cfg_only, bool live_only) {
1046 InstructionPrinter ip;
1047 for (int i = 0; i < length(); i++) {
1048 BlockBegin* block = at(i);
1049 if (cfg_only) {
1050 ip.print_instr(block); tty->cr();
1051 } else {
1052 block->print_block(ip, live_only);
1053 }
1054 }
1055 }
1056 #endif // PRODUCT
1057
1058
1059 // Implementation of BlockEnd
1060
1061 void BlockEnd::set_begin(BlockBegin* begin) {
1062 BlockList* sux = NULL;
1063 if (begin != NULL) {
1064 sux = begin->successors();
1065 } else if (this->begin() != NULL) {
1066 // copy our sux list
1067 BlockList* sux = new BlockList(this->begin()->number_of_sux());
1068 for (int i = 0; i < this->begin()->number_of_sux(); i++) {
1069 sux->append(this->begin()->sux_at(i));
1070 }
1071 }
1072 _sux = sux;
1073 }
1074
1075
1076 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) {
1077 substitute(*_sux, old_sux, new_sux);
1078 }
1079
1080
1081 // Implementation of Phi
1082
1083 // Normal phi functions take their operands from the last instruction of the
1084 // predecessor. Special handling is needed for xhanlder entries because there
1085 // the state of arbitrary instructions are needed.
1086
1087 Value Phi::operand_at(int i) const {
1088 ValueStack* state;
1089 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1090 state = _block->exception_state_at(i);
1091 } else {
1092 state = _block->pred_at(i)->end()->state();
1093 }
1094 assert(state != NULL, "");
1095
1096 if (is_local()) {
1097 return state->local_at(local_index());
1098 } else {
1099 return state->stack_at(stack_index());
1100 }
1101 }
1102
1103
1104 int Phi::operand_count() const {
1105 if (_block->is_set(BlockBegin::exception_entry_flag)) {
1106 return _block->number_of_exception_states();
1107 } else {
1108 return _block->number_of_preds();
1109 }
1110 }
1111
1112 #ifdef ASSERT
1113 // Constructor of Assert
1114 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType)
1115 , _x(x)
1116 , _cond(cond)
1117 , _y(y)
1118 {
1119 set_flag(UnorderedIsTrueFlag, unordered_is_true);
1120 assert(x->type()->tag() == y->type()->tag(), "types must match");
1121 pin();
1122
1123 stringStream strStream;
1124 Compilation::current()->method()->print_name(&strStream);
1125
1126 stringStream strStream1;
1127 InstructionPrinter ip1(1, &strStream1);
1128 ip1.print_instr(x);
1129
1130 stringStream strStream2;
1131 InstructionPrinter ip2(1, &strStream2);
1132 ip2.print_instr(y);
1133
1134 stringStream ss;
1135 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string());
1136
1137 _message = ss.as_string();
1138 }
1139 #endif
1140
1141 void RangeCheckPredicate::check_state() {
1142 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state");
1143 }
1144
1145 void ProfileInvoke::state_values_do(ValueVisitor* f) {
1146 if (state() != NULL) state()->values_do(f);
1147 }
--- EOF ---