1 /* 2 * Copyright (c) 1999, 2022, 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/ciFlatArrayKlass.hpp" 31 #include "ci/ciInlineKlass.hpp" 32 #include "ci/ciObjArrayKlass.hpp" 33 #include "ci/ciTypeArrayKlass.hpp" 34 #include "utilities/bitMap.inline.hpp" 35 36 37 // Implementation of Instruction 38 39 40 int Instruction::dominator_depth() { 41 int result = -1; 42 if (block()) { 43 result = block()->dominator_depth(); 44 } 45 assert(result != -1 || this->as_Local(), "Only locals have dominator depth -1"); 46 return result; 47 } 48 49 Instruction::Condition Instruction::mirror(Condition cond) { 50 switch (cond) { 51 case eql: return eql; 52 case neq: return neq; 53 case lss: return gtr; 54 case leq: return geq; 55 case gtr: return lss; 56 case geq: return leq; 57 case aeq: return beq; 58 case beq: return aeq; 59 } 60 ShouldNotReachHere(); 61 return eql; 62 } 63 64 65 Instruction::Condition Instruction::negate(Condition cond) { 66 switch (cond) { 67 case eql: return neq; 68 case neq: return eql; 69 case lss: return geq; 70 case leq: return gtr; 71 case gtr: return leq; 72 case geq: return lss; 73 case aeq: assert(false, "Above equal cannot be negated"); 74 case beq: assert(false, "Below equal cannot be negated"); 75 } 76 ShouldNotReachHere(); 77 return eql; 78 } 79 80 void Instruction::update_exception_state(ValueStack* state) { 81 if (state != NULL && (state->kind() == ValueStack::EmptyExceptionState || state->kind() == ValueStack::ExceptionState)) { 82 assert(state->kind() == ValueStack::EmptyExceptionState || Compilation::current()->env()->should_retain_local_variables(), "unexpected state kind"); 83 _exception_state = state; 84 } else { 85 _exception_state = NULL; 86 } 87 } 88 89 // Prev without need to have BlockBegin 90 Instruction* Instruction::prev() { 91 Instruction* p = NULL; 92 Instruction* q = block(); 93 while (q != this) { 94 assert(q != NULL, "this is not in the block's instruction list"); 95 p = q; q = q->next(); 96 } 97 return p; 98 } 99 100 101 void Instruction::state_values_do(ValueVisitor* f) { 102 if (state_before() != NULL) { 103 state_before()->values_do(f); 104 } 105 if (exception_state() != NULL){ 106 exception_state()->values_do(f); 107 } 108 } 109 110 ciType* Instruction::exact_type() const { 111 ciType* t = declared_type(); 112 if (t != NULL && t->is_klass()) { 113 return t->as_klass()->exact_klass(); 114 } 115 return NULL; 116 } 117 118 ciKlass* Instruction::as_loaded_klass_or_null() const { 119 ciType* type = declared_type(); 120 if (type != NULL && type->is_klass()) { 121 ciKlass* klass = type->as_klass(); 122 if (klass->is_loaded()) { 123 return klass; 124 } 125 } 126 return NULL; 127 } 128 129 bool Instruction::is_loaded_flattened_array() const { 130 if (UseFlatArray) { 131 ciType* type = declared_type(); 132 return type != NULL && type->is_flat_array_klass(); 133 } 134 return false; 135 } 136 137 bool Instruction::maybe_flattened_array() { 138 if (UseFlatArray) { 139 ciType* type = declared_type(); 140 if (type != NULL) { 141 if (type->is_obj_array_klass() && !type->as_obj_array_klass()->is_elem_null_free()) { 142 // The runtime type of [LMyValue might be [QMyValue due to [QMyValue <: [LMyValue. 143 ciKlass* element_klass = type->as_obj_array_klass()->element_klass(); 144 if (element_klass->can_be_inline_klass() && (!element_klass->is_inlinetype() || element_klass->as_inline_klass()->flatten_array())) { 145 return true; 146 } 147 } else if (type->is_flat_array_klass()) { 148 return true; 149 } else if (type->is_klass() && type->as_klass()->is_java_lang_Object()) { 150 // This can happen as a parameter to System.arraycopy() 151 return true; 152 } 153 } else { 154 // Type info gets lost during Phi merging (Phi, IfOp, etc), but we might be storing into a 155 // flattened array, so we should do a runtime check. 156 return true; 157 } 158 } 159 return false; 160 } 161 162 bool Instruction::maybe_null_free_array() { 163 ciType* type = declared_type(); 164 if (type != NULL) { 165 if (type->is_obj_array_klass()) { 166 // Due to array covariance, the runtime type might be a null-free array. 167 if (type->as_obj_array_klass()->can_be_inline_array_klass()) { 168 return true; 169 } 170 } 171 } else { 172 // Type info gets lost during Phi merging (Phi, IfOp, etc), but we might be storing into a 173 // null-free array, so we should do a runtime check. 174 return true; 175 } 176 return false; 177 } 178 179 #ifndef PRODUCT 180 void Instruction::check_state(ValueStack* state) { 181 if (state != NULL) { 182 state->verify(); 183 } 184 } 185 186 187 void Instruction::print() { 188 InstructionPrinter ip; 189 print(ip); 190 } 191 192 193 void Instruction::print_line() { 194 InstructionPrinter ip; 195 ip.print_line(this); 196 } 197 198 199 void Instruction::print(InstructionPrinter& ip) { 200 ip.print_head(); 201 ip.print_line(this); 202 tty->cr(); 203 } 204 #endif // PRODUCT 205 206 207 // perform constant and interval tests on index value 208 bool AccessIndexed::compute_needs_range_check() { 209 if (length()) { 210 Constant* clength = length()->as_Constant(); 211 Constant* cindex = index()->as_Constant(); 212 if (clength && cindex) { 213 IntConstant* l = clength->type()->as_IntConstant(); 214 IntConstant* i = cindex->type()->as_IntConstant(); 215 if (l && i && i->value() < l->value() && i->value() >= 0) { 216 return false; 217 } 218 } 219 } 220 221 if (!this->check_flag(NeedsRangeCheckFlag)) { 222 return false; 223 } 224 225 return true; 226 } 227 228 229 ciType* Constant::exact_type() const { 230 if (type()->is_object() && type()->as_ObjectType()->is_loaded()) { 231 return type()->as_ObjectType()->exact_type(); 232 } 233 return NULL; 234 } 235 236 ciType* LoadIndexed::exact_type() const { 237 ciType* array_type = array()->exact_type(); 238 if (delayed() == NULL && array_type != NULL) { 239 assert(array_type->is_array_klass(), "what else?"); 240 ciArrayKlass* ak = (ciArrayKlass*)array_type; 241 242 if (ak->element_type()->is_instance_klass()) { 243 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type(); 244 if (ik->is_loaded() && ik->is_final()) { 245 return ik; 246 } 247 } 248 } 249 return Instruction::exact_type(); 250 } 251 252 ciType* LoadIndexed::declared_type() const { 253 if (delayed() != NULL) { 254 return delayed()->field()->type(); 255 } 256 ciType* array_type = array()->declared_type(); 257 if (array_type == NULL || !array_type->is_loaded()) { 258 return NULL; 259 } 260 assert(array_type->is_array_klass(), "what else?"); 261 ciArrayKlass* ak = (ciArrayKlass*)array_type; 262 return ak->element_type(); 263 } 264 265 bool StoreIndexed::is_exact_flattened_array_store() const { 266 if (array()->is_loaded_flattened_array() && value()->as_Constant() == NULL && value()->declared_type() != NULL) { 267 ciKlass* element_klass = array()->declared_type()->as_flat_array_klass()->element_klass(); 268 ciKlass* actual_klass = value()->declared_type()->as_klass(); 269 270 // The following check can fail with inlining: 271 // void test45_inline(Object[] oa, Object o, int index) { oa[index] = o; } 272 // void test45(MyValue1[] va, int index, MyValue2 v) { test45_inline(va, v, index); } 273 if (element_klass == actual_klass) { 274 return true; 275 } 276 } 277 return false; 278 } 279 280 ciType* LoadField::declared_type() const { 281 return field()->type(); 282 } 283 284 285 ciType* NewTypeArray::exact_type() const { 286 return ciTypeArrayKlass::make(elt_type()); 287 } 288 289 ciType* NewObjectArray::exact_type() const { 290 return ciArrayKlass::make(klass(), is_null_free()); 291 } 292 293 ciType* NewMultiArray::exact_type() const { 294 return _klass; 295 } 296 297 ciType* NewArray::declared_type() const { 298 return exact_type(); 299 } 300 301 ciType* NewInstance::exact_type() const { 302 return klass(); 303 } 304 305 ciType* NewInstance::declared_type() const { 306 return exact_type(); 307 } 308 309 ciType* NewInlineTypeInstance::exact_type() const { 310 return klass(); 311 } 312 313 ciType* NewInlineTypeInstance::declared_type() const { 314 return exact_type(); 315 } 316 317 ciType* CheckCast::declared_type() const { 318 return klass(); 319 } 320 321 // Implementation of ArithmeticOp 322 323 bool ArithmeticOp::is_commutative() const { 324 switch (op()) { 325 case Bytecodes::_iadd: // fall through 326 case Bytecodes::_ladd: // fall through 327 case Bytecodes::_fadd: // fall through 328 case Bytecodes::_dadd: // fall through 329 case Bytecodes::_imul: // fall through 330 case Bytecodes::_lmul: // fall through 331 case Bytecodes::_fmul: // fall through 332 case Bytecodes::_dmul: return true; 333 default : return false; 334 } 335 } 336 337 338 bool ArithmeticOp::can_trap() const { 339 switch (op()) { 340 case Bytecodes::_idiv: // fall through 341 case Bytecodes::_ldiv: // fall through 342 case Bytecodes::_irem: // fall through 343 case Bytecodes::_lrem: return true; 344 default : return false; 345 } 346 } 347 348 349 // Implementation of LogicOp 350 351 bool LogicOp::is_commutative() const { 352 #ifdef ASSERT 353 switch (op()) { 354 case Bytecodes::_iand: // fall through 355 case Bytecodes::_land: // fall through 356 case Bytecodes::_ior : // fall through 357 case Bytecodes::_lor : // fall through 358 case Bytecodes::_ixor: // fall through 359 case Bytecodes::_lxor: break; 360 default : ShouldNotReachHere(); break; 361 } 362 #endif 363 // all LogicOps are commutative 364 return true; 365 } 366 367 368 // Implementation of IfOp 369 370 bool IfOp::is_commutative() const { 371 return cond() == eql || cond() == neq; 372 } 373 374 375 // Implementation of StateSplit 376 377 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) { 378 NOT_PRODUCT(bool assigned = false;) 379 for (int i = 0; i < list.length(); i++) { 380 BlockBegin** b = list.adr_at(i); 381 if (*b == old_block) { 382 *b = new_block; 383 NOT_PRODUCT(assigned = true;) 384 } 385 } 386 assert(assigned == true, "should have assigned at least once"); 387 } 388 389 390 IRScope* StateSplit::scope() const { 391 return _state->scope(); 392 } 393 394 395 void StateSplit::state_values_do(ValueVisitor* f) { 396 Instruction::state_values_do(f); 397 if (state() != NULL) state()->values_do(f); 398 } 399 400 401 void BlockBegin::state_values_do(ValueVisitor* f) { 402 StateSplit::state_values_do(f); 403 404 if (is_set(BlockBegin::exception_entry_flag)) { 405 for (int i = 0; i < number_of_exception_states(); i++) { 406 exception_state_at(i)->values_do(f); 407 } 408 } 409 } 410 411 412 StoreField::StoreField(Value obj, int offset, ciField* field, Value value, bool is_static, 413 ValueStack* state_before, bool needs_patching) 414 : AccessField(obj, offset, field, is_static, state_before, needs_patching) 415 , _value(value) 416 , _enclosing_field(NULL) 417 { 418 set_flag(NeedsWriteBarrierFlag, as_ValueType(field_type())->is_object()); 419 #ifdef ASSERT 420 AssertValues assert_value; 421 values_do(&assert_value); 422 #endif 423 pin(); 424 if (value->as_NewInlineTypeInstance() != NULL) { 425 value->as_NewInlineTypeInstance()->set_not_larva_anymore(); 426 } 427 } 428 429 StoreIndexed::StoreIndexed(Value array, Value index, Value length, BasicType elt_type, Value value, 430 ValueStack* state_before, bool check_boolean, bool mismatched) 431 : AccessIndexed(array, index, length, elt_type, state_before, mismatched) 432 , _value(value), _check_boolean(check_boolean) 433 { 434 set_flag(NeedsWriteBarrierFlag, (as_ValueType(elt_type)->is_object())); 435 set_flag(NeedsStoreCheckFlag, (as_ValueType(elt_type)->is_object())); 436 #ifdef ASSERT 437 AssertValues assert_value; 438 values_do(&assert_value); 439 #endif 440 pin(); 441 if (value->as_NewInlineTypeInstance() != NULL) { 442 value->as_NewInlineTypeInstance()->set_not_larva_anymore(); 443 } 444 } 445 446 447 // Implementation of Invoke 448 449 450 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args, 451 ciMethod* target, ValueStack* state_before, bool null_free) 452 : StateSplit(result_type, state_before) 453 , _code(code) 454 , _recv(recv) 455 , _args(args) 456 , _target(target) 457 { 458 set_flag(TargetIsLoadedFlag, target->is_loaded()); 459 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method()); 460 set_null_free(null_free); 461 462 assert(args != NULL, "args must exist"); 463 #ifdef ASSERT 464 AssertValues assert_value; 465 values_do(&assert_value); 466 #endif 467 468 // provide an initial guess of signature size. 469 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0)); 470 if (has_receiver()) { 471 _signature->append(as_BasicType(receiver()->type())); 472 if (receiver()->as_NewInlineTypeInstance() != NULL) { 473 receiver()->as_NewInlineTypeInstance()->set_not_larva_anymore(); 474 } 475 } 476 for (int i = 0; i < number_of_arguments(); i++) { 477 Value v = argument_at(i); 478 ValueType* t = v->type(); 479 BasicType bt = as_BasicType(t); 480 _signature->append(bt); 481 if (v->as_NewInlineTypeInstance() != NULL) { 482 v->as_NewInlineTypeInstance()->set_not_larva_anymore(); 483 } 484 } 485 } 486 487 488 void Invoke::state_values_do(ValueVisitor* f) { 489 StateSplit::state_values_do(f); 490 if (state_before() != NULL) state_before()->values_do(f); 491 if (state() != NULL) state()->values_do(f); 492 } 493 494 ciType* Invoke::declared_type() const { 495 ciSignature* declared_signature = state()->scope()->method()->get_declared_signature_at_bci(state()->bci()); 496 ciType *t = declared_signature->return_type(); 497 assert(t->basic_type() != T_VOID, "need return value of void method?"); 498 return t; 499 } 500 501 // Implementation of Constant 502 intx Constant::hash() const { 503 if (state_before() == NULL) { 504 switch (type()->tag()) { 505 case intTag: 506 return HASH2(name(), type()->as_IntConstant()->value()); 507 case addressTag: 508 return HASH2(name(), type()->as_AddressConstant()->value()); 509 case longTag: 510 { 511 jlong temp = type()->as_LongConstant()->value(); 512 return HASH3(name(), high(temp), low(temp)); 513 } 514 case floatTag: 515 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value())); 516 case doubleTag: 517 { 518 jlong temp = jlong_cast(type()->as_DoubleConstant()->value()); 519 return HASH3(name(), high(temp), low(temp)); 520 } 521 case objectTag: 522 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values"); 523 return HASH2(name(), type()->as_ObjectType()->constant_value()); 524 case metaDataTag: 525 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values"); 526 return HASH2(name(), type()->as_MetadataType()->constant_value()); 527 default: 528 ShouldNotReachHere(); 529 } 530 } 531 return 0; 532 } 533 534 bool Constant::is_equal(Value v) const { 535 if (v->as_Constant() == NULL) return false; 536 537 switch (type()->tag()) { 538 case intTag: 539 { 540 IntConstant* t1 = type()->as_IntConstant(); 541 IntConstant* t2 = v->type()->as_IntConstant(); 542 return (t1 != NULL && t2 != NULL && 543 t1->value() == t2->value()); 544 } 545 case longTag: 546 { 547 LongConstant* t1 = type()->as_LongConstant(); 548 LongConstant* t2 = v->type()->as_LongConstant(); 549 return (t1 != NULL && t2 != NULL && 550 t1->value() == t2->value()); 551 } 552 case floatTag: 553 { 554 FloatConstant* t1 = type()->as_FloatConstant(); 555 FloatConstant* t2 = v->type()->as_FloatConstant(); 556 return (t1 != NULL && t2 != NULL && 557 jint_cast(t1->value()) == jint_cast(t2->value())); 558 } 559 case doubleTag: 560 { 561 DoubleConstant* t1 = type()->as_DoubleConstant(); 562 DoubleConstant* t2 = v->type()->as_DoubleConstant(); 563 return (t1 != NULL && t2 != NULL && 564 jlong_cast(t1->value()) == jlong_cast(t2->value())); 565 } 566 case objectTag: 567 { 568 ObjectType* t1 = type()->as_ObjectType(); 569 ObjectType* t2 = v->type()->as_ObjectType(); 570 return (t1 != NULL && t2 != NULL && 571 t1->is_loaded() && t2->is_loaded() && 572 t1->constant_value() == t2->constant_value()); 573 } 574 case metaDataTag: 575 { 576 MetadataType* t1 = type()->as_MetadataType(); 577 MetadataType* t2 = v->type()->as_MetadataType(); 578 return (t1 != NULL && t2 != NULL && 579 t1->is_loaded() && t2->is_loaded() && 580 t1->constant_value() == t2->constant_value()); 581 } 582 default: 583 return false; 584 } 585 } 586 587 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const { 588 Constant* rc = right->as_Constant(); 589 // other is not a constant 590 if (rc == NULL) return not_comparable; 591 592 ValueType* lt = type(); 593 ValueType* rt = rc->type(); 594 // different types 595 if (lt->base() != rt->base()) return not_comparable; 596 switch (lt->tag()) { 597 case intTag: { 598 int x = lt->as_IntConstant()->value(); 599 int y = rt->as_IntConstant()->value(); 600 switch (cond) { 601 case If::eql: return x == y ? cond_true : cond_false; 602 case If::neq: return x != y ? cond_true : cond_false; 603 case If::lss: return x < y ? cond_true : cond_false; 604 case If::leq: return x <= y ? cond_true : cond_false; 605 case If::gtr: return x > y ? cond_true : cond_false; 606 case If::geq: return x >= y ? cond_true : cond_false; 607 default : break; 608 } 609 break; 610 } 611 case longTag: { 612 jlong x = lt->as_LongConstant()->value(); 613 jlong y = rt->as_LongConstant()->value(); 614 switch (cond) { 615 case If::eql: return x == y ? cond_true : cond_false; 616 case If::neq: return x != y ? cond_true : cond_false; 617 case If::lss: return x < y ? cond_true : cond_false; 618 case If::leq: return x <= y ? cond_true : cond_false; 619 case If::gtr: return x > y ? cond_true : cond_false; 620 case If::geq: return x >= y ? cond_true : cond_false; 621 default : break; 622 } 623 break; 624 } 625 case objectTag: { 626 ciObject* xvalue = lt->as_ObjectType()->constant_value(); 627 ciObject* yvalue = rt->as_ObjectType()->constant_value(); 628 assert(xvalue != NULL && yvalue != NULL, "not constants"); 629 if (xvalue->is_loaded() && yvalue->is_loaded()) { 630 switch (cond) { 631 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 632 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 633 default : break; 634 } 635 } 636 break; 637 } 638 case metaDataTag: { 639 ciMetadata* xvalue = lt->as_MetadataType()->constant_value(); 640 ciMetadata* yvalue = rt->as_MetadataType()->constant_value(); 641 assert(xvalue != NULL && yvalue != NULL, "not constants"); 642 if (xvalue->is_loaded() && yvalue->is_loaded()) { 643 switch (cond) { 644 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 645 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 646 default : break; 647 } 648 } 649 break; 650 } 651 default: 652 break; 653 } 654 return not_comparable; 655 } 656 657 658 // Implementation of BlockBegin 659 660 void BlockBegin::set_end(BlockEnd* new_end) { // Assumes that no predecessor of new_end still has it as its successor 661 assert(new_end != NULL, "Should not reset block new_end to NULL"); 662 if (new_end == _end) return; 663 664 // Remove this block as predecessor of its current successors 665 if (_end != NULL) { 666 for (int i = 0; i < number_of_sux(); i++) { 667 sux_at(i)->remove_predecessor(this); 668 } 669 } 670 671 _end = new_end; 672 673 // Add this block as predecessor of its new successors 674 for (int i = 0; i < number_of_sux(); i++) { 675 sux_at(i)->add_predecessor(this); 676 } 677 } 678 679 680 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) { 681 // disconnect any edges between from and to 682 #ifndef PRODUCT 683 if (PrintIR && Verbose) { 684 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id()); 685 } 686 #endif 687 for (int s = 0; s < from->number_of_sux();) { 688 BlockBegin* sux = from->sux_at(s); 689 if (sux == to) { 690 int index = sux->_predecessors.find(from); 691 if (index >= 0) { 692 sux->_predecessors.remove_at(index); 693 } 694 from->end()->remove_sux_at(s); 695 } else { 696 s++; 697 } 698 } 699 } 700 701 702 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 703 // modify predecessors before substituting successors 704 for (int i = 0; i < number_of_sux(); i++) { 705 if (sux_at(i) == old_sux) { 706 // remove old predecessor before adding new predecessor 707 // otherwise there is a dead predecessor in the list 708 new_sux->remove_predecessor(old_sux); 709 new_sux->add_predecessor(this); 710 } 711 } 712 old_sux->remove_predecessor(this); 713 end()->substitute_sux(old_sux, new_sux); 714 } 715 716 717 718 // In general it is not possible to calculate a value for the field "depth_first_number" 719 // of the inserted block, without recomputing the values of the other blocks 720 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless. 721 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) { 722 int bci = sux->bci(); 723 // critical edge splitting may introduce a goto after a if and array 724 // bound check elimination may insert a predicate between the if and 725 // goto. The bci of the goto can't be the one of the if otherwise 726 // the state and bci are inconsistent and a deoptimization triggered 727 // by the predicate would lead to incorrect execution/a crash. 728 BlockBegin* new_sux = new BlockBegin(bci); 729 730 // mark this block (special treatment when block order is computed) 731 new_sux->set(critical_edge_split_flag); 732 733 // This goto is not a safepoint. 734 Goto* e = new Goto(sux, false); 735 new_sux->set_next(e, bci); 736 new_sux->set_end(e); 737 // setup states 738 ValueStack* s = end()->state(); 739 new_sux->set_state(s->copy(s->kind(), bci)); 740 e->set_state(s->copy(s->kind(), bci)); 741 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!"); 742 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!"); 743 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!"); 744 745 // link predecessor to new block 746 end()->substitute_sux(sux, new_sux); 747 748 // The ordering needs to be the same, so remove the link that the 749 // set_end call above added and substitute the new_sux for this 750 // block. 751 sux->remove_predecessor(new_sux); 752 753 // the successor could be the target of a switch so it might have 754 // multiple copies of this predecessor, so substitute the new_sux 755 // for the first and delete the rest. 756 bool assigned = false; 757 BlockList& list = sux->_predecessors; 758 for (int i = 0; i < list.length(); i++) { 759 BlockBegin** b = list.adr_at(i); 760 if (*b == this) { 761 if (assigned) { 762 list.remove_at(i); 763 // reprocess this index 764 i--; 765 } else { 766 assigned = true; 767 *b = new_sux; 768 } 769 // link the new block back to it's predecessors. 770 new_sux->add_predecessor(this); 771 } 772 } 773 assert(assigned == true, "should have assigned at least once"); 774 return new_sux; 775 } 776 777 778 void BlockBegin::add_predecessor(BlockBegin* pred) { 779 _predecessors.append(pred); 780 } 781 782 783 void BlockBegin::remove_predecessor(BlockBegin* pred) { 784 int idx; 785 while ((idx = _predecessors.find(pred)) >= 0) { 786 _predecessors.remove_at(idx); 787 } 788 } 789 790 791 void BlockBegin::add_exception_handler(BlockBegin* b) { 792 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist"); 793 // add only if not in the list already 794 if (!_exception_handlers.contains(b)) _exception_handlers.append(b); 795 } 796 797 int BlockBegin::add_exception_state(ValueStack* state) { 798 assert(is_set(exception_entry_flag), "only for xhandlers"); 799 if (_exception_states == NULL) { 800 _exception_states = new ValueStackStack(4); 801 } 802 _exception_states->append(state); 803 return _exception_states->length() - 1; 804 } 805 806 807 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) { 808 if (!mark.at(block_id())) { 809 mark.at_put(block_id(), true); 810 closure->block_do(this); 811 BlockEnd* e = end(); // must do this after block_do because block_do may change it! 812 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); } 813 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); } 814 } 815 } 816 817 818 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) { 819 if (!mark.at(block_id())) { 820 mark.at_put(block_id(), true); 821 BlockEnd* e = end(); 822 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); } 823 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); } 824 closure->block_do(this); 825 } 826 } 827 828 829 void BlockBegin::iterate_preorder(BlockClosure* closure) { 830 int mark_len = number_of_blocks(); 831 boolArray mark(mark_len, mark_len, false); 832 iterate_preorder(mark, closure); 833 } 834 835 836 void BlockBegin::iterate_postorder(BlockClosure* closure) { 837 int mark_len = number_of_blocks(); 838 boolArray mark(mark_len, mark_len, false); 839 iterate_postorder(mark, closure); 840 } 841 842 843 void BlockBegin::block_values_do(ValueVisitor* f) { 844 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f); 845 } 846 847 848 #ifndef PRODUCT 849 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; } 850 #else 851 #define TRACE_PHI(coce) 852 #endif 853 854 855 bool BlockBegin::try_merge(ValueStack* new_state, bool has_irreducible_loops) { 856 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id())); 857 858 // local variables used for state iteration 859 int index; 860 Value new_value, existing_value; 861 862 ValueStack* existing_state = state(); 863 if (existing_state == NULL) { 864 TRACE_PHI(tty->print_cr("first call of try_merge for this block")); 865 866 if (is_set(BlockBegin::was_visited_flag)) { 867 // this actually happens for complicated jsr/ret structures 868 return false; // BAILOUT in caller 869 } 870 871 // copy state because it is altered 872 new_state = new_state->copy(ValueStack::BlockBeginState, bci()); 873 874 // Use method liveness to invalidate dead locals 875 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci()); 876 if (liveness.is_valid()) { 877 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness"); 878 879 for_each_local_value(new_state, index, new_value) { 880 if (!liveness.at(index) || new_value->type()->is_illegal()) { 881 new_state->invalidate_local(index); 882 TRACE_PHI(tty->print_cr("invalidating dead local %d", index)); 883 } 884 } 885 } 886 887 if (is_set(BlockBegin::parser_loop_header_flag)) { 888 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions")); 889 890 for_each_stack_value(new_state, index, new_value) { 891 new_state->setup_phi_for_stack(this, index); 892 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)); 893 } 894 895 BitMap& requires_phi_function = new_state->scope()->requires_phi_function(); 896 for_each_local_value(new_state, index, new_value) { 897 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1)); 898 if (requires_phi || !SelectivePhiFunctions || has_irreducible_loops) { 899 new_state->setup_phi_for_local(this, index); 900 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)); 901 } 902 } 903 } 904 905 // initialize state of block 906 set_state(new_state); 907 908 } else if (existing_state->is_same(new_state)) { 909 TRACE_PHI(tty->print_cr("existing state found")); 910 911 assert(existing_state->scope() == new_state->scope(), "not matching"); 912 assert(existing_state->locals_size() == new_state->locals_size(), "not matching"); 913 assert(existing_state->stack_size() == new_state->stack_size(), "not matching"); 914 915 if (is_set(BlockBegin::was_visited_flag)) { 916 TRACE_PHI(tty->print_cr("loop header block, phis must be present")); 917 918 if (!is_set(BlockBegin::parser_loop_header_flag)) { 919 // this actually happens for complicated jsr/ret structures 920 return false; // BAILOUT in caller 921 } 922 923 for_each_local_value(existing_state, index, existing_value) { 924 Value new_value = new_state->local_at(index); 925 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 926 Phi* existing_phi = existing_value->as_Phi(); 927 if (existing_phi == NULL) { 928 return false; // BAILOUT in caller 929 } 930 // Invalidate the phi function here. This case is very rare except for 931 // JVMTI capability "can_access_local_variables". 932 // In really rare cases we will bail out in LIRGenerator::move_to_phi. 933 existing_phi->make_illegal(); 934 existing_state->invalidate_local(index); 935 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 936 } 937 938 if (existing_value != new_state->local_at(index) && existing_value->as_Phi() == NULL) { 939 TRACE_PHI(tty->print_cr("required phi for local %d is missing, irreducible loop?", index)); 940 return false; // BAILOUT in caller 941 } 942 } 943 944 #ifdef ASSERT 945 // check that all necessary phi functions are present 946 for_each_stack_value(existing_state, index, existing_value) { 947 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required"); 948 } 949 for_each_local_value(existing_state, index, existing_value) { 950 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required"); 951 } 952 #endif 953 954 } else { 955 TRACE_PHI(tty->print_cr("creating phi functions on demand")); 956 957 // create necessary phi functions for stack 958 for_each_stack_value(existing_state, index, existing_value) { 959 Value new_value = new_state->stack_at(index); 960 Phi* existing_phi = existing_value->as_Phi(); 961 962 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 963 existing_state->setup_phi_for_stack(this, index); 964 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)); 965 if (new_value->as_NewInlineTypeInstance() != NULL) {new_value->as_NewInlineTypeInstance()->set_not_larva_anymore(); } 966 if (existing_value->as_NewInlineTypeInstance() != NULL) {existing_value->as_NewInlineTypeInstance()->set_not_larva_anymore(); } 967 } 968 } 969 970 // create necessary phi functions for locals 971 for_each_local_value(existing_state, index, existing_value) { 972 Value new_value = new_state->local_at(index); 973 Phi* existing_phi = existing_value->as_Phi(); 974 975 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 976 existing_state->invalidate_local(index); 977 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 978 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 979 existing_state->setup_phi_for_local(this, index); 980 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)); 981 if (new_value->as_NewInlineTypeInstance() != NULL) {new_value->as_NewInlineTypeInstance()->set_not_larva_anymore(); } 982 if (existing_value->as_NewInlineTypeInstance() != NULL) {existing_value->as_NewInlineTypeInstance()->set_not_larva_anymore(); } 983 } 984 } 985 } 986 987 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal"); 988 989 } else { 990 assert(false, "stack or locks not matching (invalid bytecodes)"); 991 return false; 992 } 993 994 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id())); 995 996 return true; 997 } 998 999 1000 #ifndef PRODUCT 1001 void BlockBegin::print_block() { 1002 InstructionPrinter ip; 1003 print_block(ip, false); 1004 } 1005 1006 1007 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) { 1008 ip.print_instr(this); tty->cr(); 1009 ip.print_stack(this->state()); tty->cr(); 1010 ip.print_inline_level(this); 1011 ip.print_head(); 1012 for (Instruction* n = next(); n != NULL; n = n->next()) { 1013 if (!live_only || n->is_pinned() || n->use_count() > 0) { 1014 ip.print_line(n); 1015 } 1016 } 1017 tty->cr(); 1018 } 1019 #endif // PRODUCT 1020 1021 1022 // Implementation of BlockList 1023 1024 void BlockList::iterate_forward (BlockClosure* closure) { 1025 const int l = length(); 1026 for (int i = 0; i < l; i++) closure->block_do(at(i)); 1027 } 1028 1029 1030 void BlockList::iterate_backward(BlockClosure* closure) { 1031 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i)); 1032 } 1033 1034 1035 void BlockList::values_do(ValueVisitor* f) { 1036 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f); 1037 } 1038 1039 1040 #ifndef PRODUCT 1041 void BlockList::print(bool cfg_only, bool live_only) { 1042 InstructionPrinter ip; 1043 for (int i = 0; i < length(); i++) { 1044 BlockBegin* block = at(i); 1045 if (cfg_only) { 1046 ip.print_instr(block); tty->cr(); 1047 } else { 1048 block->print_block(ip, live_only); 1049 } 1050 } 1051 } 1052 #endif // PRODUCT 1053 1054 1055 // Implementation of BlockEnd 1056 1057 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 1058 substitute(*_sux, old_sux, new_sux); 1059 } 1060 1061 // Implementation of Phi 1062 1063 // Normal phi functions take their operands from the last instruction of the 1064 // predecessor. Special handling is needed for xhanlder entries because there 1065 // the state of arbitrary instructions are needed. 1066 1067 Value Phi::operand_at(int i) const { 1068 ValueStack* state; 1069 if (_block->is_set(BlockBegin::exception_entry_flag)) { 1070 state = _block->exception_state_at(i); 1071 } else { 1072 state = _block->pred_at(i)->end()->state(); 1073 } 1074 assert(state != NULL, ""); 1075 1076 if (is_local()) { 1077 return state->local_at(local_index()); 1078 } else { 1079 return state->stack_at(stack_index()); 1080 } 1081 } 1082 1083 1084 int Phi::operand_count() const { 1085 if (_block->is_set(BlockBegin::exception_entry_flag)) { 1086 return _block->number_of_exception_states(); 1087 } else { 1088 return _block->number_of_preds(); 1089 } 1090 } 1091 1092 #ifdef ASSERT 1093 // Constructor of Assert 1094 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType) 1095 , _x(x) 1096 , _cond(cond) 1097 , _y(y) 1098 { 1099 set_flag(UnorderedIsTrueFlag, unordered_is_true); 1100 assert(x->type()->tag() == y->type()->tag(), "types must match"); 1101 pin(); 1102 1103 stringStream strStream; 1104 Compilation::current()->method()->print_name(&strStream); 1105 1106 stringStream strStream1; 1107 InstructionPrinter ip1(1, &strStream1); 1108 ip1.print_instr(x); 1109 1110 stringStream strStream2; 1111 InstructionPrinter ip2(1, &strStream2); 1112 ip2.print_instr(y); 1113 1114 stringStream ss; 1115 ss.print("Assertion %s %s %s in method %s", strStream1.freeze(), ip2.cond_name(cond), strStream2.freeze(), strStream.freeze()); 1116 1117 _message = ss.as_string(); 1118 } 1119 #endif 1120 1121 void RangeCheckPredicate::check_state() { 1122 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state"); 1123 } 1124 1125 void ProfileInvoke::state_values_do(ValueVisitor* f) { 1126 if (state() != NULL) state()->values_do(f); 1127 } 1128