c1_Instruction.cpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 1999, 2010, 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 "incls/_precompiled.incl" 26#include "incls/_c1_Instruction.cpp.incl" 27 28 29// Implementation of Instruction 30 31 32int Instruction::_next_id = 0; 33 34#ifdef ASSERT 35void Instruction::create_hi_word() { 36 assert(type()->is_double_word() && _hi_word == NULL, "only double word has high word"); 37 _hi_word = new HiWord(this); 38} 39#endif 40 41Instruction::Condition Instruction::mirror(Condition cond) { 42 switch (cond) { 43 case eql: return eql; 44 case neq: return neq; 45 case lss: return gtr; 46 case leq: return geq; 47 case gtr: return lss; 48 case geq: return leq; 49 } 50 ShouldNotReachHere(); 51 return eql; 52} 53 54 55Instruction::Condition Instruction::negate(Condition cond) { 56 switch (cond) { 57 case eql: return neq; 58 case neq: return eql; 59 case lss: return geq; 60 case leq: return gtr; 61 case gtr: return leq; 62 case geq: return lss; 63 } 64 ShouldNotReachHere(); 65 return eql; 66} 67 68 69Instruction* Instruction::prev(BlockBegin* block) { 70 Instruction* p = NULL; 71 Instruction* q = block; 72 while (q != this) { 73 assert(q != NULL, "this is not in the block's instruction list"); 74 p = q; q = q->next(); 75 } 76 return p; 77} 78 79 80#ifndef PRODUCT 81void Instruction::print() { 82 InstructionPrinter ip; 83 print(ip); 84} 85 86 87void Instruction::print_line() { 88 InstructionPrinter ip; 89 ip.print_line(this); 90} 91 92 93void Instruction::print(InstructionPrinter& ip) { 94 ip.print_head(); 95 ip.print_line(this); 96 tty->cr(); 97} 98#endif // PRODUCT 99 100 101// perform constant and interval tests on index value 102bool AccessIndexed::compute_needs_range_check() { 103 Constant* clength = length()->as_Constant(); 104 Constant* cindex = index()->as_Constant(); 105 if (clength && cindex) { 106 IntConstant* l = clength->type()->as_IntConstant(); 107 IntConstant* i = cindex->type()->as_IntConstant(); 108 if (l && i && i->value() < l->value() && i->value() >= 0) { 109 return false; 110 } 111 } 112 return true; 113} 114 115 116ciType* LoadIndexed::exact_type() const { 117 ciType* array_type = array()->exact_type(); 118 if (array_type == NULL) { 119 return NULL; 120 } 121 assert(array_type->is_array_klass(), "what else?"); 122 ciArrayKlass* ak = (ciArrayKlass*)array_type; 123 124 if (ak->element_type()->is_instance_klass()) { 125 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type(); 126 if (ik->is_loaded() && ik->is_final()) { 127 return ik; 128 } 129 } 130 return NULL; 131} 132 133 134ciType* LoadIndexed::declared_type() const { 135 ciType* array_type = array()->declared_type(); 136 if (array_type == NULL) { 137 return NULL; 138 } 139 assert(array_type->is_array_klass(), "what else?"); 140 ciArrayKlass* ak = (ciArrayKlass*)array_type; 141 return ak->element_type(); 142} 143 144 145ciType* LoadField::declared_type() const { 146 return field()->type(); 147} 148 149 150ciType* LoadField::exact_type() const { 151 ciType* type = declared_type(); 152 // for primitive arrays, the declared type is the exact type 153 if (type->is_type_array_klass()) { 154 return type; 155 } 156 if (type->is_instance_klass()) { 157 ciInstanceKlass* ik = (ciInstanceKlass*)type; 158 if (ik->is_loaded() && ik->is_final()) { 159 return type; 160 } 161 } 162 return NULL; 163} 164 165 166ciType* NewTypeArray::exact_type() const { 167 return ciTypeArrayKlass::make(elt_type()); 168} 169 170 171ciType* NewObjectArray::exact_type() const { 172 return ciObjArrayKlass::make(klass()); 173} 174 175 176ciType* NewInstance::exact_type() const { 177 return klass(); 178} 179 180 181ciType* CheckCast::declared_type() const { 182 return klass(); 183} 184 185ciType* CheckCast::exact_type() const { 186 if (klass()->is_instance_klass()) { 187 ciInstanceKlass* ik = (ciInstanceKlass*)klass(); 188 if (ik->is_loaded() && ik->is_final()) { 189 return ik; 190 } 191 } 192 return NULL; 193} 194 195 196void ArithmeticOp::other_values_do(void f(Value*)) { 197 if (lock_stack() != NULL) lock_stack()->values_do(f); 198} 199 200void NullCheck::other_values_do(void f(Value*)) { 201 lock_stack()->values_do(f); 202} 203 204void AccessArray::other_values_do(void f(Value*)) { 205 if (lock_stack() != NULL) lock_stack()->values_do(f); 206} 207 208 209// Implementation of AccessField 210 211void AccessField::other_values_do(void f(Value*)) { 212 if (state_before() != NULL) state_before()->values_do(f); 213 if (lock_stack() != NULL) lock_stack()->values_do(f); 214} 215 216 217// Implementation of StoreIndexed 218 219IRScope* StoreIndexed::scope() const { 220 return lock_stack()->scope(); 221} 222 223 224// Implementation of ArithmeticOp 225 226bool ArithmeticOp::is_commutative() const { 227 switch (op()) { 228 case Bytecodes::_iadd: // fall through 229 case Bytecodes::_ladd: // fall through 230 case Bytecodes::_fadd: // fall through 231 case Bytecodes::_dadd: // fall through 232 case Bytecodes::_imul: // fall through 233 case Bytecodes::_lmul: // fall through 234 case Bytecodes::_fmul: // fall through 235 case Bytecodes::_dmul: return true; 236 } 237 return false; 238} 239 240 241bool ArithmeticOp::can_trap() const { 242 switch (op()) { 243 case Bytecodes::_idiv: // fall through 244 case Bytecodes::_ldiv: // fall through 245 case Bytecodes::_irem: // fall through 246 case Bytecodes::_lrem: return true; 247 } 248 return false; 249} 250 251 252// Implementation of LogicOp 253 254bool LogicOp::is_commutative() const { 255#ifdef ASSERT 256 switch (op()) { 257 case Bytecodes::_iand: // fall through 258 case Bytecodes::_land: // fall through 259 case Bytecodes::_ior : // fall through 260 case Bytecodes::_lor : // fall through 261 case Bytecodes::_ixor: // fall through 262 case Bytecodes::_lxor: break; 263 default : ShouldNotReachHere(); 264 } 265#endif 266 // all LogicOps are commutative 267 return true; 268} 269 270 271// Implementation of CompareOp 272 273void CompareOp::other_values_do(void f(Value*)) { 274 if (state_before() != NULL) state_before()->values_do(f); 275} 276 277 278// Implementation of IfOp 279 280bool IfOp::is_commutative() const { 281 return cond() == eql || cond() == neq; 282} 283 284 285// Implementation of StateSplit 286 287void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) { 288 NOT_PRODUCT(bool assigned = false;) 289 for (int i = 0; i < list.length(); i++) { 290 BlockBegin** b = list.adr_at(i); 291 if (*b == old_block) { 292 *b = new_block; 293 NOT_PRODUCT(assigned = true;) 294 } 295 } 296 assert(assigned == true, "should have assigned at least once"); 297} 298 299 300IRScope* StateSplit::scope() const { 301 return _state->scope(); 302} 303 304 305void StateSplit::state_values_do(void f(Value*)) { 306 if (state() != NULL) state()->values_do(f); 307} 308 309 310void BlockBegin::state_values_do(void f(Value*)) { 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 321void MonitorEnter::state_values_do(void f(Value*)) { 322 StateSplit::state_values_do(f); 323 _lock_stack_before->values_do(f); 324} 325 326 327void Intrinsic::state_values_do(void f(Value*)) { 328 StateSplit::state_values_do(f); 329 if (lock_stack() != NULL) lock_stack()->values_do(f); 330} 331 332 333// Implementation of Invoke 334 335 336Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args, 337 int vtable_index, ciMethod* target, ValueStack* state_before) 338 : StateSplit(result_type) 339 , _code(code) 340 , _recv(recv) 341 , _args(args) 342 , _vtable_index(vtable_index) 343 , _target(target) 344 , _state_before(state_before) 345{ 346 set_flag(TargetIsLoadedFlag, target->is_loaded()); 347 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method()); 348 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict()); 349 350 assert(args != NULL, "args must exist"); 351#ifdef ASSERT 352 values_do(assert_value); 353#endif // ASSERT 354 355 // provide an initial guess of signature size. 356 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0)); 357 if (has_receiver()) { 358 _signature->append(as_BasicType(receiver()->type())); 359 } else if (is_invokedynamic()) { 360 // Add the synthetic MethodHandle argument to the signature. 361 _signature->append(T_OBJECT); 362 } 363 for (int i = 0; i < number_of_arguments(); i++) { 364 ValueType* t = argument_at(i)->type(); 365 BasicType bt = as_BasicType(t); 366 _signature->append(bt); 367 } 368} 369 370 371void Invoke::state_values_do(void f(Value*)) { 372 StateSplit::state_values_do(f); 373 if (state_before() != NULL) state_before()->values_do(f); 374 if (state() != NULL) state()->values_do(f); 375} 376 377 378// Implementation of Contant 379intx Constant::hash() const { 380 if (_state == NULL) { 381 switch (type()->tag()) { 382 case intTag: 383 return HASH2(name(), type()->as_IntConstant()->value()); 384 case longTag: 385 { 386 jlong temp = type()->as_LongConstant()->value(); 387 return HASH3(name(), high(temp), low(temp)); 388 } 389 case floatTag: 390 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value())); 391 case doubleTag: 392 { 393 jlong temp = jlong_cast(type()->as_DoubleConstant()->value()); 394 return HASH3(name(), high(temp), low(temp)); 395 } 396 case objectTag: 397 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values"); 398 return HASH2(name(), type()->as_ObjectType()->constant_value()); 399 } 400 } 401 return 0; 402} 403 404bool Constant::is_equal(Value v) const { 405 if (v->as_Constant() == NULL) return false; 406 407 switch (type()->tag()) { 408 case intTag: 409 { 410 IntConstant* t1 = type()->as_IntConstant(); 411 IntConstant* t2 = v->type()->as_IntConstant(); 412 return (t1 != NULL && t2 != NULL && 413 t1->value() == t2->value()); 414 } 415 case longTag: 416 { 417 LongConstant* t1 = type()->as_LongConstant(); 418 LongConstant* t2 = v->type()->as_LongConstant(); 419 return (t1 != NULL && t2 != NULL && 420 t1->value() == t2->value()); 421 } 422 case floatTag: 423 { 424 FloatConstant* t1 = type()->as_FloatConstant(); 425 FloatConstant* t2 = v->type()->as_FloatConstant(); 426 return (t1 != NULL && t2 != NULL && 427 jint_cast(t1->value()) == jint_cast(t2->value())); 428 } 429 case doubleTag: 430 { 431 DoubleConstant* t1 = type()->as_DoubleConstant(); 432 DoubleConstant* t2 = v->type()->as_DoubleConstant(); 433 return (t1 != NULL && t2 != NULL && 434 jlong_cast(t1->value()) == jlong_cast(t2->value())); 435 } 436 case objectTag: 437 { 438 ObjectType* t1 = type()->as_ObjectType(); 439 ObjectType* t2 = v->type()->as_ObjectType(); 440 return (t1 != NULL && t2 != NULL && 441 t1->is_loaded() && t2->is_loaded() && 442 t1->constant_value() == t2->constant_value()); 443 } 444 } 445 return false; 446} 447 448 449BlockBegin* Constant::compare(Instruction::Condition cond, Value right, 450 BlockBegin* true_sux, BlockBegin* false_sux) { 451 Constant* rc = right->as_Constant(); 452 // other is not a constant 453 if (rc == NULL) return NULL; 454 455 ValueType* lt = type(); 456 ValueType* rt = rc->type(); 457 // different types 458 if (lt->base() != rt->base()) return NULL; 459 switch (lt->tag()) { 460 case intTag: { 461 int x = lt->as_IntConstant()->value(); 462 int y = rt->as_IntConstant()->value(); 463 switch (cond) { 464 case If::eql: return x == y ? true_sux : false_sux; 465 case If::neq: return x != y ? true_sux : false_sux; 466 case If::lss: return x < y ? true_sux : false_sux; 467 case If::leq: return x <= y ? true_sux : false_sux; 468 case If::gtr: return x > y ? true_sux : false_sux; 469 case If::geq: return x >= y ? true_sux : false_sux; 470 } 471 break; 472 } 473 case longTag: { 474 jlong x = lt->as_LongConstant()->value(); 475 jlong y = rt->as_LongConstant()->value(); 476 switch (cond) { 477 case If::eql: return x == y ? true_sux : false_sux; 478 case If::neq: return x != y ? true_sux : false_sux; 479 case If::lss: return x < y ? true_sux : false_sux; 480 case If::leq: return x <= y ? true_sux : false_sux; 481 case If::gtr: return x > y ? true_sux : false_sux; 482 case If::geq: return x >= y ? true_sux : false_sux; 483 } 484 break; 485 } 486 case objectTag: { 487 ciObject* xvalue = lt->as_ObjectType()->constant_value(); 488 ciObject* yvalue = rt->as_ObjectType()->constant_value(); 489 assert(xvalue != NULL && yvalue != NULL, "not constants"); 490 if (xvalue->is_loaded() && yvalue->is_loaded()) { 491 switch (cond) { 492 case If::eql: return xvalue == yvalue ? true_sux : false_sux; 493 case If::neq: return xvalue != yvalue ? true_sux : false_sux; 494 } 495 } 496 break; 497 } 498 } 499 return NULL; 500} 501 502 503void Constant::other_values_do(void f(Value*)) { 504 if (state() != NULL) state()->values_do(f); 505} 506 507 508// Implementation of NewArray 509 510void NewArray::other_values_do(void f(Value*)) { 511 if (state_before() != NULL) state_before()->values_do(f); 512} 513 514 515// Implementation of TypeCheck 516 517void TypeCheck::other_values_do(void f(Value*)) { 518 if (state_before() != NULL) state_before()->values_do(f); 519} 520 521 522// Implementation of BlockBegin 523 524int BlockBegin::_next_block_id = 0; 525 526 527void BlockBegin::set_end(BlockEnd* end) { 528 assert(end != NULL, "should not reset block end to NULL"); 529 BlockEnd* old_end = _end; 530 if (end == old_end) { 531 return; 532 } 533 // Must make the predecessors/successors match up with the 534 // BlockEnd's notion. 535 int i, n; 536 if (old_end != NULL) { 537 // disconnect from the old end 538 old_end->set_begin(NULL); 539 540 // disconnect this block from it's current successors 541 for (i = 0; i < _successors.length(); i++) { 542 _successors.at(i)->remove_predecessor(this); 543 } 544 } 545 _end = end; 546 547 _successors.clear(); 548 // Now reset successors list based on BlockEnd 549 n = end->number_of_sux(); 550 for (i = 0; i < n; i++) { 551 BlockBegin* sux = end->sux_at(i); 552 _successors.append(sux); 553 sux->_predecessors.append(this); 554 } 555 _end->set_begin(this); 556} 557 558 559void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) { 560 // disconnect any edges between from and to 561#ifndef PRODUCT 562 if (PrintIR && Verbose) { 563 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id()); 564 } 565#endif 566 for (int s = 0; s < from->number_of_sux();) { 567 BlockBegin* sux = from->sux_at(s); 568 if (sux == to) { 569 int index = sux->_predecessors.index_of(from); 570 if (index >= 0) { 571 sux->_predecessors.remove_at(index); 572 } 573 from->_successors.remove_at(s); 574 } else { 575 s++; 576 } 577 } 578} 579 580 581void BlockBegin::disconnect_from_graph() { 582 // disconnect this block from all other blocks 583 for (int p = 0; p < number_of_preds(); p++) { 584 pred_at(p)->remove_successor(this); 585 } 586 for (int s = 0; s < number_of_sux(); s++) { 587 sux_at(s)->remove_predecessor(this); 588 } 589} 590 591void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 592 // modify predecessors before substituting successors 593 for (int i = 0; i < number_of_sux(); i++) { 594 if (sux_at(i) == old_sux) { 595 // remove old predecessor before adding new predecessor 596 // otherwise there is a dead predecessor in the list 597 new_sux->remove_predecessor(old_sux); 598 new_sux->add_predecessor(this); 599 } 600 } 601 old_sux->remove_predecessor(this); 602 end()->substitute_sux(old_sux, new_sux); 603} 604 605 606 607// In general it is not possible to calculate a value for the field "depth_first_number" 608// of the inserted block, without recomputing the values of the other blocks 609// in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless. 610BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) { 611 // Try to make the bci close to a block with a single pred or sux, 612 // since this make the block layout algorithm work better. 613 int bci = -1; 614 if (sux->number_of_preds() == 1) { 615 bci = sux->bci(); 616 } else { 617 bci = end()->bci(); 618 } 619 620 BlockBegin* new_sux = new BlockBegin(bci); 621 622 // mark this block (special treatment when block order is computed) 623 new_sux->set(critical_edge_split_flag); 624 625 // This goto is not a safepoint. 626 Goto* e = new Goto(sux, false); 627 new_sux->set_next(e, bci); 628 new_sux->set_end(e); 629 // setup states 630 ValueStack* s = end()->state(); 631 new_sux->set_state(s->copy()); 632 e->set_state(s->copy()); 633 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!"); 634 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!"); 635 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!"); 636 637 // link predecessor to new block 638 end()->substitute_sux(sux, new_sux); 639 640 // The ordering needs to be the same, so remove the link that the 641 // set_end call above added and substitute the new_sux for this 642 // block. 643 sux->remove_predecessor(new_sux); 644 645 // the successor could be the target of a switch so it might have 646 // multiple copies of this predecessor, so substitute the new_sux 647 // for the first and delete the rest. 648 bool assigned = false; 649 BlockList& list = sux->_predecessors; 650 for (int i = 0; i < list.length(); i++) { 651 BlockBegin** b = list.adr_at(i); 652 if (*b == this) { 653 if (assigned) { 654 list.remove_at(i); 655 // reprocess this index 656 i--; 657 } else { 658 assigned = true; 659 *b = new_sux; 660 } 661 // link the new block back to it's predecessors. 662 new_sux->add_predecessor(this); 663 } 664 } 665 assert(assigned == true, "should have assigned at least once"); 666 return new_sux; 667} 668 669 670void BlockBegin::remove_successor(BlockBegin* pred) { 671 int idx; 672 while ((idx = _successors.index_of(pred)) >= 0) { 673 _successors.remove_at(idx); 674 } 675} 676 677 678void BlockBegin::add_predecessor(BlockBegin* pred) { 679 _predecessors.append(pred); 680} 681 682 683void BlockBegin::remove_predecessor(BlockBegin* pred) { 684 int idx; 685 while ((idx = _predecessors.index_of(pred)) >= 0) { 686 _predecessors.remove_at(idx); 687 } 688} 689 690 691void BlockBegin::add_exception_handler(BlockBegin* b) { 692 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist"); 693 // add only if not in the list already 694 if (!_exception_handlers.contains(b)) _exception_handlers.append(b); 695} 696 697int BlockBegin::add_exception_state(ValueStack* state) { 698 assert(is_set(exception_entry_flag), "only for xhandlers"); 699 if (_exception_states == NULL) { 700 _exception_states = new ValueStackStack(4); 701 } 702 _exception_states->append(state); 703 return _exception_states->length() - 1; 704} 705 706 707void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) { 708 if (!mark.at(block_id())) { 709 mark.at_put(block_id(), true); 710 closure->block_do(this); 711 BlockEnd* e = end(); // must do this after block_do because block_do may change it! 712 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); } 713 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); } 714 } 715} 716 717 718void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) { 719 if (!mark.at(block_id())) { 720 mark.at_put(block_id(), true); 721 BlockEnd* e = end(); 722 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); } 723 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); } 724 closure->block_do(this); 725 } 726} 727 728 729void BlockBegin::iterate_preorder(BlockClosure* closure) { 730 boolArray mark(number_of_blocks(), false); 731 iterate_preorder(mark, closure); 732} 733 734 735void BlockBegin::iterate_postorder(BlockClosure* closure) { 736 boolArray mark(number_of_blocks(), false); 737 iterate_postorder(mark, closure); 738} 739 740 741void BlockBegin::block_values_do(void f(Value*)) { 742 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f); 743} 744 745 746#ifndef PRODUCT 747 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; } 748#else 749 #define TRACE_PHI(coce) 750#endif 751 752 753bool BlockBegin::try_merge(ValueStack* new_state) { 754 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id())); 755 756 // local variables used for state iteration 757 int index; 758 Value new_value, existing_value; 759 760 ValueStack* existing_state = state(); 761 if (existing_state == NULL) { 762 TRACE_PHI(tty->print_cr("first call of try_merge for this block")); 763 764 if (is_set(BlockBegin::was_visited_flag)) { 765 // this actually happens for complicated jsr/ret structures 766 return false; // BAILOUT in caller 767 } 768 769 // copy state because it is altered 770 new_state = new_state->copy(); 771 772 // Use method liveness to invalidate dead locals 773 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci()); 774 if (liveness.is_valid()) { 775 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness"); 776 777 for_each_local_value(new_state, index, new_value) { 778 if (!liveness.at(index) || new_value->type()->is_illegal()) { 779 new_state->invalidate_local(index); 780 TRACE_PHI(tty->print_cr("invalidating dead local %d", index)); 781 } 782 } 783 } 784 785 if (is_set(BlockBegin::parser_loop_header_flag)) { 786 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions")); 787 788 for_each_stack_value(new_state, index, new_value) { 789 new_state->setup_phi_for_stack(this, index); 790 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)); 791 } 792 793 BitMap requires_phi_function = new_state->scope()->requires_phi_function(); 794 795 for_each_local_value(new_state, index, new_value) { 796 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1)); 797 if (requires_phi || !SelectivePhiFunctions) { 798 new_state->setup_phi_for_local(this, index); 799 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)); 800 } 801 } 802 } 803 804 // initialize state of block 805 set_state(new_state); 806 807 } else if (existing_state->is_same_across_scopes(new_state)) { 808 TRACE_PHI(tty->print_cr("exisiting state found")); 809 810 // Inlining may cause the local state not to match up, so walk up 811 // the new state until we get to the same scope as the 812 // existing and then start processing from there. 813 while (existing_state->scope() != new_state->scope()) { 814 new_state = new_state->caller_state(); 815 assert(new_state != NULL, "could not match up scopes"); 816 817 assert(false, "check if this is necessary"); 818 } 819 820 assert(existing_state->scope() == new_state->scope(), "not matching"); 821 assert(existing_state->locals_size() == new_state->locals_size(), "not matching"); 822 assert(existing_state->stack_size() == new_state->stack_size(), "not matching"); 823 824 if (is_set(BlockBegin::was_visited_flag)) { 825 TRACE_PHI(tty->print_cr("loop header block, phis must be present")); 826 827 if (!is_set(BlockBegin::parser_loop_header_flag)) { 828 // this actually happens for complicated jsr/ret structures 829 return false; // BAILOUT in caller 830 } 831 832 for_each_local_value(existing_state, index, existing_value) { 833 Value new_value = new_state->local_at(index); 834 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 835 // The old code invalidated the phi function here 836 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out 837 return false; // BAILOUT in caller 838 } 839 } 840 841#ifdef ASSERT 842 // check that all necessary phi functions are present 843 for_each_stack_value(existing_state, index, existing_value) { 844 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required"); 845 } 846 for_each_local_value(existing_state, index, existing_value) { 847 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required"); 848 } 849#endif 850 851 } else { 852 TRACE_PHI(tty->print_cr("creating phi functions on demand")); 853 854 // create necessary phi functions for stack 855 for_each_stack_value(existing_state, index, existing_value) { 856 Value new_value = new_state->stack_at(index); 857 Phi* existing_phi = existing_value->as_Phi(); 858 859 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 860 existing_state->setup_phi_for_stack(this, index); 861 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)); 862 } 863 } 864 865 // create necessary phi functions for locals 866 for_each_local_value(existing_state, index, existing_value) { 867 Value new_value = new_state->local_at(index); 868 Phi* existing_phi = existing_value->as_Phi(); 869 870 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 871 existing_state->invalidate_local(index); 872 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 873 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 874 existing_state->setup_phi_for_local(this, index); 875 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)); 876 } 877 } 878 } 879 880 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal"); 881 882 } else { 883 assert(false, "stack or locks not matching (invalid bytecodes)"); 884 return false; 885 } 886 887 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id())); 888 889 return true; 890} 891 892 893#ifndef PRODUCT 894void BlockBegin::print_block() { 895 InstructionPrinter ip; 896 print_block(ip, false); 897} 898 899 900void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) { 901 ip.print_instr(this); tty->cr(); 902 ip.print_stack(this->state()); tty->cr(); 903 ip.print_inline_level(this); 904 ip.print_head(); 905 for (Instruction* n = next(); n != NULL; n = n->next()) { 906 if (!live_only || n->is_pinned() || n->use_count() > 0) { 907 ip.print_line(n); 908 } 909 } 910 tty->cr(); 911} 912#endif // PRODUCT 913 914 915// Implementation of BlockList 916 917void BlockList::iterate_forward (BlockClosure* closure) { 918 const int l = length(); 919 for (int i = 0; i < l; i++) closure->block_do(at(i)); 920} 921 922 923void BlockList::iterate_backward(BlockClosure* closure) { 924 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i)); 925} 926 927 928void BlockList::blocks_do(void f(BlockBegin*)) { 929 for (int i = length() - 1; i >= 0; i--) f(at(i)); 930} 931 932 933void BlockList::values_do(void f(Value*)) { 934 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f); 935} 936 937 938#ifndef PRODUCT 939void BlockList::print(bool cfg_only, bool live_only) { 940 InstructionPrinter ip; 941 for (int i = 0; i < length(); i++) { 942 BlockBegin* block = at(i); 943 if (cfg_only) { 944 ip.print_instr(block); tty->cr(); 945 } else { 946 block->print_block(ip, live_only); 947 } 948 } 949} 950#endif // PRODUCT 951 952 953// Implementation of BlockEnd 954 955void BlockEnd::set_begin(BlockBegin* begin) { 956 BlockList* sux = NULL; 957 if (begin != NULL) { 958 sux = begin->successors(); 959 } else if (_begin != NULL) { 960 // copy our sux list 961 BlockList* sux = new BlockList(_begin->number_of_sux()); 962 for (int i = 0; i < _begin->number_of_sux(); i++) { 963 sux->append(_begin->sux_at(i)); 964 } 965 } 966 _sux = sux; 967 _begin = begin; 968} 969 970 971void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 972 substitute(*_sux, old_sux, new_sux); 973} 974 975 976void BlockEnd::other_values_do(void f(Value*)) { 977 if (state_before() != NULL) state_before()->values_do(f); 978} 979 980 981// Implementation of Phi 982 983// Normal phi functions take their operands from the last instruction of the 984// predecessor. Special handling is needed for xhanlder entries because there 985// the state of arbitrary instructions are needed. 986 987Value Phi::operand_at(int i) const { 988 ValueStack* state; 989 if (_block->is_set(BlockBegin::exception_entry_flag)) { 990 state = _block->exception_state_at(i); 991 } else { 992 state = _block->pred_at(i)->end()->state(); 993 } 994 assert(state != NULL, ""); 995 996 if (is_local()) { 997 return state->local_at(local_index()); 998 } else { 999 return state->stack_at(stack_index()); 1000 } 1001} 1002 1003 1004int Phi::operand_count() const { 1005 if (_block->is_set(BlockBegin::exception_entry_flag)) { 1006 return _block->number_of_exception_states(); 1007 } else { 1008 return _block->number_of_preds(); 1009 } 1010} 1011 1012 1013// Implementation of Throw 1014 1015void Throw::state_values_do(void f(Value*)) { 1016 BlockEnd::state_values_do(f); 1017} 1018