1/* 2 * Copyright (c) 1999, 2016, 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 37int 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 46Instruction::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 62Instruction::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 77void 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 87Instruction* 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 98void 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 107ciType* 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 117void Instruction::check_state(ValueStack* state) { 118 if (state != NULL) { 119 state->verify(); 120 } 121} 122 123 124void Instruction::print() { 125 InstructionPrinter ip; 126 print(ip); 127} 128 129 130void Instruction::print_line() { 131 InstructionPrinter ip; 132 ip.print_line(this); 133} 134 135 136void 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 145bool 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 166ciType* 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 173ciType* 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 190ciType* 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 201ciType* LoadField::declared_type() const { 202 return field()->type(); 203} 204 205 206ciType* NewTypeArray::exact_type() const { 207 return ciTypeArrayKlass::make(elt_type()); 208} 209 210ciType* NewObjectArray::exact_type() const { 211 return ciObjArrayKlass::make(klass()); 212} 213 214ciType* NewArray::declared_type() const { 215 return exact_type(); 216} 217 218ciType* NewInstance::exact_type() const { 219 return klass(); 220} 221 222ciType* NewInstance::declared_type() const { 223 return exact_type(); 224} 225 226ciType* CheckCast::declared_type() const { 227 return klass(); 228} 229 230// Implementation of ArithmeticOp 231 232bool 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 } 243 return false; 244} 245 246 247bool 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 } 254 return false; 255} 256 257 258// Implementation of LogicOp 259 260bool 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(); 270 } 271#endif 272 // all LogicOps are commutative 273 return true; 274} 275 276 277// Implementation of IfOp 278 279bool IfOp::is_commutative() const { 280 return cond() == eql || cond() == neq; 281} 282 283 284// Implementation of StateSplit 285 286void 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 299IRScope* StateSplit::scope() const { 300 return _state->scope(); 301} 302 303 304void StateSplit::state_values_do(ValueVisitor* f) { 305 Instruction::state_values_do(f); 306 if (state() != NULL) state()->values_do(f); 307} 308 309 310void 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 324Invoke::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 356void 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 362ciType* 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 370intx 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 402bool 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 } 451 return false; 452} 453 454Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const { 455 Constant* rc = right->as_Constant(); 456 // other is not a constant 457 if (rc == NULL) return not_comparable; 458 459 ValueType* lt = type(); 460 ValueType* rt = rc->type(); 461 // different types 462 if (lt->base() != rt->base()) return not_comparable; 463 switch (lt->tag()) { 464 case intTag: { 465 int x = lt->as_IntConstant()->value(); 466 int y = rt->as_IntConstant()->value(); 467 switch (cond) { 468 case If::eql: return x == y ? cond_true : cond_false; 469 case If::neq: return x != y ? cond_true : cond_false; 470 case If::lss: return x < y ? cond_true : cond_false; 471 case If::leq: return x <= y ? cond_true : cond_false; 472 case If::gtr: return x > y ? cond_true : cond_false; 473 case If::geq: return x >= y ? cond_true : cond_false; 474 } 475 break; 476 } 477 case longTag: { 478 jlong x = lt->as_LongConstant()->value(); 479 jlong y = rt->as_LongConstant()->value(); 480 switch (cond) { 481 case If::eql: return x == y ? cond_true : cond_false; 482 case If::neq: return x != y ? cond_true : cond_false; 483 case If::lss: return x < y ? cond_true : cond_false; 484 case If::leq: return x <= y ? cond_true : cond_false; 485 case If::gtr: return x > y ? cond_true : cond_false; 486 case If::geq: return x >= y ? cond_true : cond_false; 487 } 488 break; 489 } 490 case objectTag: { 491 ciObject* xvalue = lt->as_ObjectType()->constant_value(); 492 ciObject* yvalue = rt->as_ObjectType()->constant_value(); 493 assert(xvalue != NULL && yvalue != NULL, "not constants"); 494 if (xvalue->is_loaded() && yvalue->is_loaded()) { 495 switch (cond) { 496 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 497 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 498 } 499 } 500 break; 501 } 502 case metaDataTag: { 503 ciMetadata* xvalue = lt->as_MetadataType()->constant_value(); 504 ciMetadata* yvalue = rt->as_MetadataType()->constant_value(); 505 assert(xvalue != NULL && yvalue != NULL, "not constants"); 506 if (xvalue->is_loaded() && yvalue->is_loaded()) { 507 switch (cond) { 508 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 509 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 510 } 511 } 512 break; 513 } 514 } 515 return not_comparable; 516} 517 518 519// Implementation of BlockBegin 520 521void BlockBegin::set_end(BlockEnd* end) { 522 assert(end != NULL, "should not reset block end to NULL"); 523 if (end == _end) { 524 return; 525 } 526 clear_end(); 527 528 // Set the new end 529 _end = end; 530 531 _successors.clear(); 532 // Now reset successors list based on BlockEnd 533 for (int i = 0; i < end->number_of_sux(); i++) { 534 BlockBegin* sux = end->sux_at(i); 535 _successors.append(sux); 536 sux->_predecessors.append(this); 537 } 538 _end->set_begin(this); 539} 540 541 542void BlockBegin::clear_end() { 543 // Must make the predecessors/successors match up with the 544 // BlockEnd's notion. 545 if (_end != NULL) { 546 // disconnect from the old end 547 _end->set_begin(NULL); 548 549 // disconnect this block from it's current successors 550 for (int i = 0; i < _successors.length(); i++) { 551 _successors.at(i)->remove_predecessor(this); 552 } 553 _end = NULL; 554 } 555} 556 557 558void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) { 559 // disconnect any edges between from and to 560#ifndef PRODUCT 561 if (PrintIR && Verbose) { 562 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id()); 563 } 564#endif 565 for (int s = 0; s < from->number_of_sux();) { 566 BlockBegin* sux = from->sux_at(s); 567 if (sux == to) { 568 int index = sux->_predecessors.find(from); 569 if (index >= 0) { 570 sux->_predecessors.remove_at(index); 571 } 572 from->_successors.remove_at(s); 573 } else { 574 s++; 575 } 576 } 577} 578 579 580void BlockBegin::disconnect_from_graph() { 581 // disconnect this block from all other blocks 582 for (int p = 0; p < number_of_preds(); p++) { 583 pred_at(p)->remove_successor(this); 584 } 585 for (int s = 0; s < number_of_sux(); s++) { 586 sux_at(s)->remove_predecessor(this); 587 } 588} 589 590void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 591 // modify predecessors before substituting successors 592 for (int i = 0; i < number_of_sux(); i++) { 593 if (sux_at(i) == old_sux) { 594 // remove old predecessor before adding new predecessor 595 // otherwise there is a dead predecessor in the list 596 new_sux->remove_predecessor(old_sux); 597 new_sux->add_predecessor(this); 598 } 599 } 600 old_sux->remove_predecessor(this); 601 end()->substitute_sux(old_sux, new_sux); 602} 603 604 605 606// In general it is not possible to calculate a value for the field "depth_first_number" 607// of the inserted block, without recomputing the values of the other blocks 608// in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless. 609BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) { 610 int bci = sux->bci(); 611 // critical edge splitting may introduce a goto after a if and array 612 // bound check elimination may insert a predicate between the if and 613 // goto. The bci of the goto can't be the one of the if otherwise 614 // the state and bci are inconsistent and a deoptimization triggered 615 // by the predicate would lead to incorrect execution/a crash. 616 BlockBegin* new_sux = new BlockBegin(bci); 617 618 // mark this block (special treatment when block order is computed) 619 new_sux->set(critical_edge_split_flag); 620 621 // This goto is not a safepoint. 622 Goto* e = new Goto(sux, false); 623 new_sux->set_next(e, bci); 624 new_sux->set_end(e); 625 // setup states 626 ValueStack* s = end()->state(); 627 new_sux->set_state(s->copy(s->kind(), bci)); 628 e->set_state(s->copy(s->kind(), bci)); 629 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!"); 630 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!"); 631 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!"); 632 633 // link predecessor to new block 634 end()->substitute_sux(sux, new_sux); 635 636 // The ordering needs to be the same, so remove the link that the 637 // set_end call above added and substitute the new_sux for this 638 // block. 639 sux->remove_predecessor(new_sux); 640 641 // the successor could be the target of a switch so it might have 642 // multiple copies of this predecessor, so substitute the new_sux 643 // for the first and delete the rest. 644 bool assigned = false; 645 BlockList& list = sux->_predecessors; 646 for (int i = 0; i < list.length(); i++) { 647 BlockBegin** b = list.adr_at(i); 648 if (*b == this) { 649 if (assigned) { 650 list.remove_at(i); 651 // reprocess this index 652 i--; 653 } else { 654 assigned = true; 655 *b = new_sux; 656 } 657 // link the new block back to it's predecessors. 658 new_sux->add_predecessor(this); 659 } 660 } 661 assert(assigned == true, "should have assigned at least once"); 662 return new_sux; 663} 664 665 666void BlockBegin::remove_successor(BlockBegin* pred) { 667 int idx; 668 while ((idx = _successors.find(pred)) >= 0) { 669 _successors.remove_at(idx); 670 } 671} 672 673 674void BlockBegin::add_predecessor(BlockBegin* pred) { 675 _predecessors.append(pred); 676} 677 678 679void BlockBegin::remove_predecessor(BlockBegin* pred) { 680 int idx; 681 while ((idx = _predecessors.find(pred)) >= 0) { 682 _predecessors.remove_at(idx); 683 } 684} 685 686 687void BlockBegin::add_exception_handler(BlockBegin* b) { 688 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist"); 689 // add only if not in the list already 690 if (!_exception_handlers.contains(b)) _exception_handlers.append(b); 691} 692 693int BlockBegin::add_exception_state(ValueStack* state) { 694 assert(is_set(exception_entry_flag), "only for xhandlers"); 695 if (_exception_states == NULL) { 696 _exception_states = new ValueStackStack(4); 697 } 698 _exception_states->append(state); 699 return _exception_states->length() - 1; 700} 701 702 703void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) { 704 if (!mark.at(block_id())) { 705 mark.at_put(block_id(), true); 706 closure->block_do(this); 707 BlockEnd* e = end(); // must do this after block_do because block_do may change it! 708 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); } 709 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); } 710 } 711} 712 713 714void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) { 715 if (!mark.at(block_id())) { 716 mark.at_put(block_id(), true); 717 BlockEnd* e = end(); 718 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); } 719 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); } 720 closure->block_do(this); 721 } 722} 723 724 725void BlockBegin::iterate_preorder(BlockClosure* closure) { 726 int mark_len = number_of_blocks(); 727 boolArray mark(mark_len, mark_len, false); 728 iterate_preorder(mark, closure); 729} 730 731 732void BlockBegin::iterate_postorder(BlockClosure* closure) { 733 int mark_len = number_of_blocks(); 734 boolArray mark(mark_len, mark_len, false); 735 iterate_postorder(mark, closure); 736} 737 738 739void BlockBegin::block_values_do(ValueVisitor* f) { 740 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f); 741} 742 743 744#ifndef PRODUCT 745 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; } 746#else 747 #define TRACE_PHI(coce) 748#endif 749 750 751bool BlockBegin::try_merge(ValueStack* new_state) { 752 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id())); 753 754 // local variables used for state iteration 755 int index; 756 Value new_value, existing_value; 757 758 ValueStack* existing_state = state(); 759 if (existing_state == NULL) { 760 TRACE_PHI(tty->print_cr("first call of try_merge for this block")); 761 762 if (is_set(BlockBegin::was_visited_flag)) { 763 // this actually happens for complicated jsr/ret structures 764 return false; // BAILOUT in caller 765 } 766 767 // copy state because it is altered 768 new_state = new_state->copy(ValueStack::BlockBeginState, bci()); 769 770 // Use method liveness to invalidate dead locals 771 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci()); 772 if (liveness.is_valid()) { 773 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness"); 774 775 for_each_local_value(new_state, index, new_value) { 776 if (!liveness.at(index) || new_value->type()->is_illegal()) { 777 new_state->invalidate_local(index); 778 TRACE_PHI(tty->print_cr("invalidating dead local %d", index)); 779 } 780 } 781 } 782 783 if (is_set(BlockBegin::parser_loop_header_flag)) { 784 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions")); 785 786 for_each_stack_value(new_state, index, new_value) { 787 new_state->setup_phi_for_stack(this, index); 788 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)); 789 } 790 791 BitMap& requires_phi_function = new_state->scope()->requires_phi_function(); 792 793 for_each_local_value(new_state, index, new_value) { 794 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1)); 795 if (requires_phi || !SelectivePhiFunctions) { 796 new_state->setup_phi_for_local(this, index); 797 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)); 798 } 799 } 800 } 801 802 // initialize state of block 803 set_state(new_state); 804 805 } else if (existing_state->is_same(new_state)) { 806 TRACE_PHI(tty->print_cr("exisiting state found")); 807 808 assert(existing_state->scope() == new_state->scope(), "not matching"); 809 assert(existing_state->locals_size() == new_state->locals_size(), "not matching"); 810 assert(existing_state->stack_size() == new_state->stack_size(), "not matching"); 811 812 if (is_set(BlockBegin::was_visited_flag)) { 813 TRACE_PHI(tty->print_cr("loop header block, phis must be present")); 814 815 if (!is_set(BlockBegin::parser_loop_header_flag)) { 816 // this actually happens for complicated jsr/ret structures 817 return false; // BAILOUT in caller 818 } 819 820 for_each_local_value(existing_state, index, existing_value) { 821 Value new_value = new_state->local_at(index); 822 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 823 // The old code invalidated the phi function here 824 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out 825 return false; // BAILOUT in caller 826 } 827 } 828 829#ifdef ASSERT 830 // check that all necessary phi functions are present 831 for_each_stack_value(existing_state, index, existing_value) { 832 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required"); 833 } 834 for_each_local_value(existing_state, index, existing_value) { 835 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required"); 836 } 837#endif 838 839 } else { 840 TRACE_PHI(tty->print_cr("creating phi functions on demand")); 841 842 // create necessary phi functions for stack 843 for_each_stack_value(existing_state, index, existing_value) { 844 Value new_value = new_state->stack_at(index); 845 Phi* existing_phi = existing_value->as_Phi(); 846 847 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 848 existing_state->setup_phi_for_stack(this, index); 849 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)); 850 } 851 } 852 853 // create necessary phi functions for locals 854 for_each_local_value(existing_state, index, existing_value) { 855 Value new_value = new_state->local_at(index); 856 Phi* existing_phi = existing_value->as_Phi(); 857 858 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 859 existing_state->invalidate_local(index); 860 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 861 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 862 existing_state->setup_phi_for_local(this, index); 863 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)); 864 } 865 } 866 } 867 868 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal"); 869 870 } else { 871 assert(false, "stack or locks not matching (invalid bytecodes)"); 872 return false; 873 } 874 875 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id())); 876 877 return true; 878} 879 880 881#ifndef PRODUCT 882void BlockBegin::print_block() { 883 InstructionPrinter ip; 884 print_block(ip, false); 885} 886 887 888void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) { 889 ip.print_instr(this); tty->cr(); 890 ip.print_stack(this->state()); tty->cr(); 891 ip.print_inline_level(this); 892 ip.print_head(); 893 for (Instruction* n = next(); n != NULL; n = n->next()) { 894 if (!live_only || n->is_pinned() || n->use_count() > 0) { 895 ip.print_line(n); 896 } 897 } 898 tty->cr(); 899} 900#endif // PRODUCT 901 902 903// Implementation of BlockList 904 905void BlockList::iterate_forward (BlockClosure* closure) { 906 const int l = length(); 907 for (int i = 0; i < l; i++) closure->block_do(at(i)); 908} 909 910 911void BlockList::iterate_backward(BlockClosure* closure) { 912 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i)); 913} 914 915 916void BlockList::blocks_do(void f(BlockBegin*)) { 917 for (int i = length() - 1; i >= 0; i--) f(at(i)); 918} 919 920 921void BlockList::values_do(ValueVisitor* f) { 922 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f); 923} 924 925 926#ifndef PRODUCT 927void BlockList::print(bool cfg_only, bool live_only) { 928 InstructionPrinter ip; 929 for (int i = 0; i < length(); i++) { 930 BlockBegin* block = at(i); 931 if (cfg_only) { 932 ip.print_instr(block); tty->cr(); 933 } else { 934 block->print_block(ip, live_only); 935 } 936 } 937} 938#endif // PRODUCT 939 940 941// Implementation of BlockEnd 942 943void BlockEnd::set_begin(BlockBegin* begin) { 944 BlockList* sux = NULL; 945 if (begin != NULL) { 946 sux = begin->successors(); 947 } else if (this->begin() != NULL) { 948 // copy our sux list 949 BlockList* sux = new BlockList(this->begin()->number_of_sux()); 950 for (int i = 0; i < this->begin()->number_of_sux(); i++) { 951 sux->append(this->begin()->sux_at(i)); 952 } 953 } 954 _sux = sux; 955} 956 957 958void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 959 substitute(*_sux, old_sux, new_sux); 960} 961 962 963// Implementation of Phi 964 965// Normal phi functions take their operands from the last instruction of the 966// predecessor. Special handling is needed for xhanlder entries because there 967// the state of arbitrary instructions are needed. 968 969Value Phi::operand_at(int i) const { 970 ValueStack* state; 971 if (_block->is_set(BlockBegin::exception_entry_flag)) { 972 state = _block->exception_state_at(i); 973 } else { 974 state = _block->pred_at(i)->end()->state(); 975 } 976 assert(state != NULL, ""); 977 978 if (is_local()) { 979 return state->local_at(local_index()); 980 } else { 981 return state->stack_at(stack_index()); 982 } 983} 984 985 986int Phi::operand_count() const { 987 if (_block->is_set(BlockBegin::exception_entry_flag)) { 988 return _block->number_of_exception_states(); 989 } else { 990 return _block->number_of_preds(); 991 } 992} 993 994#ifdef ASSERT 995// Constructor of Assert 996Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType) 997 , _x(x) 998 , _cond(cond) 999 , _y(y) 1000{ 1001 set_flag(UnorderedIsTrueFlag, unordered_is_true); 1002 assert(x->type()->tag() == y->type()->tag(), "types must match"); 1003 pin(); 1004 1005 stringStream strStream; 1006 Compilation::current()->method()->print_name(&strStream); 1007 1008 stringStream strStream1; 1009 InstructionPrinter ip1(1, &strStream1); 1010 ip1.print_instr(x); 1011 1012 stringStream strStream2; 1013 InstructionPrinter ip2(1, &strStream2); 1014 ip2.print_instr(y); 1015 1016 stringStream ss; 1017 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string()); 1018 1019 _message = ss.as_string(); 1020} 1021#endif 1022 1023void RangeCheckPredicate::check_state() { 1024 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state"); 1025} 1026 1027void ProfileInvoke::state_values_do(ValueVisitor* f) { 1028 if (state() != NULL) state()->values_do(f); 1029} 1030