1 /* 2 * Copyright 1999-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 #include "incls/_precompiled.incl" 26 #include "incls/_c1_Instruction.cpp.incl" 27 28 29 // Implementation of Instruction 30 31 32 int Instruction::_next_id = 0; 33 34 #ifdef ASSERT 35 void 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 41 Instruction::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 55 Instruction::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 69 Instruction* 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 81 void Instruction::print() { 82 InstructionPrinter ip; 83 print(ip); 84 } 85 86 87 void Instruction::print_line() { 88 InstructionPrinter ip; 89 ip.print_line(this); 90 } 91 92 93 void 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 102 bool 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 } 114 115 116 ciType* 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 } 132 133 134 ciType* 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 } 143 144 145 ciType* LoadField::declared_type() const { 146 return field()->type(); 147 } 148 149 150 ciType* 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 } 164 165 166 ciType* NewTypeArray::exact_type() const { 167 return ciTypeArrayKlass::make(elt_type()); 168 } 169 170 171 ciType* NewObjectArray::exact_type() const { 172 return ciObjArrayKlass::make(klass()); 173 } 174 175 176 ciType* NewInstance::exact_type() const { 177 return klass(); 178 } 179 180 181 ciType* CheckCast::declared_type() const { 182 return klass(); 183 } 184 185 ciType* 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 } 194 195 196 void ArithmeticOp::other_values_do(void f(Value*)) { 197 if (lock_stack() != NULL) lock_stack()->values_do(f); 198 } 199 200 void NullCheck::other_values_do(void f(Value*)) { 201 lock_stack()->values_do(f); 202 } 203 204 void AccessArray::other_values_do(void f(Value*)) { 205 if (lock_stack() != NULL) lock_stack()->values_do(f); 206 } 207 208 209 // Implementation of AccessField 210 211 void 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 218 219 IRScope* StoreIndexed::scope() const { 220 return lock_stack()->scope(); 221 } 222 223 224 // Implementation of ArithmeticOp 225 226 bool 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 } 239 240 241 bool 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 253 254 bool 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 272 273 void CompareOp::other_values_do(void f(Value*)) { 274 if (state_before() != NULL) state_before()->values_do(f); 275 } 276 277 278 // Implementation of IfOp 279 280 bool IfOp::is_commutative() const { 281 return cond() == eql || cond() == neq; 282 } 283 284 285 // Implementation of StateSplit 286 287 void 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 } 298 299 300 IRScope* StateSplit::scope() const { 301 return _state->scope(); 302 } 303 304 305 void StateSplit::state_values_do(void f(Value*)) { 306 if (state() != NULL) state()->values_do(f); 307 } 308 309 310 void 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 } 319 320 321 void MonitorEnter::state_values_do(void f(Value*)) { 322 StateSplit::state_values_do(f); 323 _lock_stack_before->values_do(f); 324 } 325 326 327 void 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 334 335 336 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args, 337 int vtable_index, ciMethod* target) 338 : StateSplit(result_type) 339 , _code(code) 340 , _recv(recv) 341 , _args(args) 342 , _vtable_index(vtable_index) 343 , _target(target) 344 { 345 set_flag(TargetIsLoadedFlag, target->is_loaded()); 346 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method()); 347 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict()); 348 349 assert(args != NULL, "args must exist"); 350 #ifdef ASSERT 351 values_do(assert_value); 352 #endif // ASSERT 353 354 // provide an initial guess of signature size. 355 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0)); 356 if (has_receiver()) { 357 _signature->append(as_BasicType(receiver()->type())); 358 } 359 for (int i = 0; i < number_of_arguments(); i++) { 360 ValueType* t = argument_at(i)->type(); 361 BasicType bt = as_BasicType(t); 362 _signature->append(bt); 363 } 364 } 365 366 367 // Implementation of Contant 368 intx Constant::hash() const { 369 if (_state == NULL) { 370 switch (type()->tag()) { 371 case intTag: 372 return HASH2(name(), type()->as_IntConstant()->value()); 373 case longTag: 374 { 375 jlong temp = type()->as_LongConstant()->value(); 376 return HASH3(name(), high(temp), low(temp)); 377 } 378 case floatTag: 379 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value())); 380 case doubleTag: 381 { 382 jlong temp = jlong_cast(type()->as_DoubleConstant()->value()); 383 return HASH3(name(), high(temp), low(temp)); 384 } 385 case objectTag: 386 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values"); 387 return HASH2(name(), type()->as_ObjectType()->constant_value()); 388 } 389 } 390 return 0; 391 } 392 393 bool Constant::is_equal(Value v) const { 394 if (v->as_Constant() == NULL) return false; 395 396 switch (type()->tag()) { 397 case intTag: 398 { 399 IntConstant* t1 = type()->as_IntConstant(); 400 IntConstant* t2 = v->type()->as_IntConstant(); 401 return (t1 != NULL && t2 != NULL && 402 t1->value() == t2->value()); 403 } 404 case longTag: 405 { 406 LongConstant* t1 = type()->as_LongConstant(); 407 LongConstant* t2 = v->type()->as_LongConstant(); 408 return (t1 != NULL && t2 != NULL && 409 t1->value() == t2->value()); 410 } 411 case floatTag: 412 { 413 FloatConstant* t1 = type()->as_FloatConstant(); 414 FloatConstant* t2 = v->type()->as_FloatConstant(); 415 return (t1 != NULL && t2 != NULL && 416 jint_cast(t1->value()) == jint_cast(t2->value())); 417 } 418 case doubleTag: 419 { 420 DoubleConstant* t1 = type()->as_DoubleConstant(); 421 DoubleConstant* t2 = v->type()->as_DoubleConstant(); 422 return (t1 != NULL && t2 != NULL && 423 jlong_cast(t1->value()) == jlong_cast(t2->value())); 424 } 425 case objectTag: 426 { 427 ObjectType* t1 = type()->as_ObjectType(); 428 ObjectType* t2 = v->type()->as_ObjectType(); 429 return (t1 != NULL && t2 != NULL && 430 t1->is_loaded() && t2->is_loaded() && 431 t1->constant_value() == t2->constant_value()); 432 } 433 } 434 return false; 435 } 436 437 438 BlockBegin* Constant::compare(Instruction::Condition cond, Value right, 439 BlockBegin* true_sux, BlockBegin* false_sux) { 440 Constant* rc = right->as_Constant(); 441 // other is not a constant 442 if (rc == NULL) return NULL; 443 444 ValueType* lt = type(); 445 ValueType* rt = rc->type(); 446 // different types 447 if (lt->base() != rt->base()) return NULL; 448 switch (lt->tag()) { 449 case intTag: { 450 int x = lt->as_IntConstant()->value(); 451 int y = rt->as_IntConstant()->value(); 452 switch (cond) { 453 case If::eql: return x == y ? true_sux : false_sux; 454 case If::neq: return x != y ? true_sux : false_sux; 455 case If::lss: return x < y ? true_sux : false_sux; 456 case If::leq: return x <= y ? true_sux : false_sux; 457 case If::gtr: return x > y ? true_sux : false_sux; 458 case If::geq: return x >= y ? true_sux : false_sux; 459 } 460 break; 461 } 462 case longTag: { 463 jlong x = lt->as_LongConstant()->value(); 464 jlong y = rt->as_LongConstant()->value(); 465 switch (cond) { 466 case If::eql: return x == y ? true_sux : false_sux; 467 case If::neq: return x != y ? true_sux : false_sux; 468 case If::lss: return x < y ? true_sux : false_sux; 469 case If::leq: return x <= y ? true_sux : false_sux; 470 case If::gtr: return x > y ? true_sux : false_sux; 471 case If::geq: return x >= y ? true_sux : false_sux; 472 } 473 break; 474 } 475 case objectTag: { 476 ciObject* xvalue = lt->as_ObjectType()->constant_value(); 477 ciObject* yvalue = rt->as_ObjectType()->constant_value(); 478 assert(xvalue != NULL && yvalue != NULL, "not constants"); 479 if (xvalue->is_loaded() && yvalue->is_loaded()) { 480 switch (cond) { 481 case If::eql: return xvalue == yvalue ? true_sux : false_sux; 482 case If::neq: return xvalue != yvalue ? true_sux : false_sux; 483 } 484 } 485 break; 486 } 487 } 488 return NULL; 489 } 490 491 492 void Constant::other_values_do(void f(Value*)) { 493 if (state() != NULL) state()->values_do(f); 494 } 495 496 497 // Implementation of NewArray 498 499 void NewArray::other_values_do(void f(Value*)) { 500 if (state_before() != NULL) state_before()->values_do(f); 501 } 502 503 504 // Implementation of TypeCheck 505 506 void TypeCheck::other_values_do(void f(Value*)) { 507 if (state_before() != NULL) state_before()->values_do(f); 508 } 509 510 511 // Implementation of BlockBegin 512 513 int BlockBegin::_next_block_id = 0; 514 515 516 void BlockBegin::set_end(BlockEnd* end) { 517 assert(end != NULL, "should not reset block end to NULL"); 518 BlockEnd* old_end = _end; 519 if (end == old_end) { 520 return; 521 } 522 // Must make the predecessors/successors match up with the 523 // BlockEnd's notion. 524 int i, n; 525 if (old_end != NULL) { 526 // disconnect from the old end 527 old_end->set_begin(NULL); 528 529 // disconnect this block from it's current successors 530 for (i = 0; i < _successors.length(); i++) { 531 _successors.at(i)->remove_predecessor(this); 532 } 533 } 534 _end = end; 535 536 _successors.clear(); 537 // Now reset successors list based on BlockEnd 538 n = end->number_of_sux(); 539 for (i = 0; i < n; i++) { 540 BlockBegin* sux = end->sux_at(i); 541 _successors.append(sux); 542 sux->_predecessors.append(this); 543 } 544 _end->set_begin(this); 545 } 546 547 548 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) { 549 // disconnect any edges between from and to 550 #ifndef PRODUCT 551 if (PrintIR && Verbose) { 552 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id()); 553 } 554 #endif 555 for (int s = 0; s < from->number_of_sux();) { 556 BlockBegin* sux = from->sux_at(s); 557 if (sux == to) { 558 int index = sux->_predecessors.index_of(from); 559 if (index >= 0) { 560 sux->_predecessors.remove_at(index); 561 } 562 from->_successors.remove_at(s); 563 } else { 564 s++; 565 } 566 } 567 } 568 569 570 void BlockBegin::disconnect_from_graph() { 571 // disconnect this block from all other blocks 572 for (int p = 0; p < number_of_preds(); p++) { 573 pred_at(p)->remove_successor(this); 574 } 575 for (int s = 0; s < number_of_sux(); s++) { 576 sux_at(s)->remove_predecessor(this); 577 } 578 } 579 580 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 581 // modify predecessors before substituting successors 582 for (int i = 0; i < number_of_sux(); i++) { 583 if (sux_at(i) == old_sux) { 584 // remove old predecessor before adding new predecessor 585 // otherwise there is a dead predecessor in the list 586 new_sux->remove_predecessor(old_sux); 587 new_sux->add_predecessor(this); 588 } 589 } 590 old_sux->remove_predecessor(this); 591 end()->substitute_sux(old_sux, new_sux); 592 } 593 594 595 596 // In general it is not possible to calculate a value for the field "depth_first_number" 597 // of the inserted block, without recomputing the values of the other blocks 598 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless. 599 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) { 600 // Try to make the bci close to a block with a single pred or sux, 601 // since this make the block layout algorithm work better. 602 int bci = -1; 603 if (sux->number_of_preds() == 1) { 604 bci = sux->bci(); 605 } else { 606 bci = end()->bci(); 607 } 608 609 BlockBegin* new_sux = new BlockBegin(bci); 610 611 // mark this block (special treatment when block order is computed) 612 new_sux->set(critical_edge_split_flag); 613 614 // This goto is not a safepoint. 615 Goto* e = new Goto(sux, false); 616 new_sux->set_next(e, bci); 617 new_sux->set_end(e); 618 // setup states 619 ValueStack* s = end()->state(); 620 new_sux->set_state(s->copy()); 621 e->set_state(s->copy()); 622 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!"); 623 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!"); 624 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!"); 625 626 // link predecessor to new block 627 end()->substitute_sux(sux, new_sux); 628 629 // The ordering needs to be the same, so remove the link that the 630 // set_end call above added and substitute the new_sux for this 631 // block. 632 sux->remove_predecessor(new_sux); 633 634 // the successor could be the target of a switch so it might have 635 // multiple copies of this predecessor, so substitute the new_sux 636 // for the first and delete the rest. 637 bool assigned = false; 638 BlockList& list = sux->_predecessors; 639 for (int i = 0; i < list.length(); i++) { 640 BlockBegin** b = list.adr_at(i); 641 if (*b == this) { 642 if (assigned) { 643 list.remove_at(i); 644 // reprocess this index 645 i--; 646 } else { 647 assigned = true; 648 *b = new_sux; 649 } 650 // link the new block back to it's predecessors. 651 new_sux->add_predecessor(this); 652 } 653 } 654 assert(assigned == true, "should have assigned at least once"); 655 return new_sux; 656 } 657 658 659 void BlockBegin::remove_successor(BlockBegin* pred) { 660 int idx; 661 while ((idx = _successors.index_of(pred)) >= 0) { 662 _successors.remove_at(idx); 663 } 664 } 665 666 667 void BlockBegin::add_predecessor(BlockBegin* pred) { 668 _predecessors.append(pred); 669 } 670 671 672 void BlockBegin::remove_predecessor(BlockBegin* pred) { 673 int idx; 674 while ((idx = _predecessors.index_of(pred)) >= 0) { 675 _predecessors.remove_at(idx); 676 } 677 } 678 679 680 void BlockBegin::add_exception_handler(BlockBegin* b) { 681 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist"); 682 // add only if not in the list already 683 if (!_exception_handlers.contains(b)) _exception_handlers.append(b); 684 } 685 686 int BlockBegin::add_exception_state(ValueStack* state) { 687 assert(is_set(exception_entry_flag), "only for xhandlers"); 688 if (_exception_states == NULL) { 689 _exception_states = new ValueStackStack(4); 690 } 691 _exception_states->append(state); 692 return _exception_states->length() - 1; 693 } 694 695 696 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) { 697 if (!mark.at(block_id())) { 698 mark.at_put(block_id(), true); 699 closure->block_do(this); 700 BlockEnd* e = end(); // must do this after block_do because block_do may change it! 701 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); } 702 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); } 703 } 704 } 705 706 707 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) { 708 if (!mark.at(block_id())) { 709 mark.at_put(block_id(), true); 710 BlockEnd* e = end(); 711 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); } 712 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); } 713 closure->block_do(this); 714 } 715 } 716 717 718 void BlockBegin::iterate_preorder(BlockClosure* closure) { 719 boolArray mark(number_of_blocks(), false); 720 iterate_preorder(mark, closure); 721 } 722 723 724 void BlockBegin::iterate_postorder(BlockClosure* closure) { 725 boolArray mark(number_of_blocks(), false); 726 iterate_postorder(mark, closure); 727 } 728 729 730 void BlockBegin::block_values_do(void f(Value*)) { 731 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f); 732 } 733 734 735 #ifndef PRODUCT 736 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; } 737 #else 738 #define TRACE_PHI(coce) 739 #endif 740 741 742 bool BlockBegin::try_merge(ValueStack* new_state) { 743 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id())); 744 745 // local variables used for state iteration 746 int index; 747 Value new_value, existing_value; 748 749 ValueStack* existing_state = state(); 750 if (existing_state == NULL) { 751 TRACE_PHI(tty->print_cr("first call of try_merge for this block")); 752 753 if (is_set(BlockBegin::was_visited_flag)) { 754 // this actually happens for complicated jsr/ret structures 755 return false; // BAILOUT in caller 756 } 757 758 // copy state because it is altered 759 new_state = new_state->copy(); 760 761 // Use method liveness to invalidate dead locals 762 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci()); 763 if (liveness.is_valid()) { 764 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness"); 765 766 for_each_local_value(new_state, index, new_value) { 767 if (!liveness.at(index) || new_value->type()->is_illegal()) { 768 new_state->invalidate_local(index); 769 TRACE_PHI(tty->print_cr("invalidating dead local %d", index)); 770 } 771 } 772 } 773 774 if (is_set(BlockBegin::parser_loop_header_flag)) { 775 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions")); 776 777 for_each_stack_value(new_state, index, new_value) { 778 new_state->setup_phi_for_stack(this, index); 779 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)); 780 } 781 782 BitMap requires_phi_function = new_state->scope()->requires_phi_function(); 783 784 for_each_local_value(new_state, index, new_value) { 785 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1)); 786 if (requires_phi || !SelectivePhiFunctions) { 787 new_state->setup_phi_for_local(this, index); 788 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)); 789 } 790 } 791 } 792 793 // initialize state of block 794 set_state(new_state); 795 796 } else if (existing_state->is_same_across_scopes(new_state)) { 797 TRACE_PHI(tty->print_cr("exisiting state found")); 798 799 // Inlining may cause the local state not to match up, so walk up 800 // the new state until we get to the same scope as the 801 // existing and then start processing from there. 802 while (existing_state->scope() != new_state->scope()) { 803 new_state = new_state->caller_state(); 804 assert(new_state != NULL, "could not match up scopes"); 805 806 assert(false, "check if this is necessary"); 807 } 808 809 assert(existing_state->scope() == new_state->scope(), "not matching"); 810 assert(existing_state->locals_size() == new_state->locals_size(), "not matching"); 811 assert(existing_state->stack_size() == new_state->stack_size(), "not matching"); 812 813 if (is_set(BlockBegin::was_visited_flag)) { 814 TRACE_PHI(tty->print_cr("loop header block, phis must be present")); 815 816 if (!is_set(BlockBegin::parser_loop_header_flag)) { 817 // this actually happens for complicated jsr/ret structures 818 return false; // BAILOUT in caller 819 } 820 821 for_each_local_value(existing_state, index, existing_value) { 822 Value new_value = new_state->local_at(index); 823 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 824 // The old code invalidated the phi function here 825 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out 826 return false; // BAILOUT in caller 827 } 828 } 829 830 #ifdef ASSERT 831 // check that all necessary phi functions are present 832 for_each_stack_value(existing_state, index, existing_value) { 833 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required"); 834 } 835 for_each_local_value(existing_state, index, existing_value) { 836 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required"); 837 } 838 #endif 839 840 } else { 841 TRACE_PHI(tty->print_cr("creating phi functions on demand")); 842 843 // create necessary phi functions for stack 844 for_each_stack_value(existing_state, index, existing_value) { 845 Value new_value = new_state->stack_at(index); 846 Phi* existing_phi = existing_value->as_Phi(); 847 848 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 849 existing_state->setup_phi_for_stack(this, index); 850 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)); 851 } 852 } 853 854 // create necessary phi functions for locals 855 for_each_local_value(existing_state, index, existing_value) { 856 Value new_value = new_state->local_at(index); 857 Phi* existing_phi = existing_value->as_Phi(); 858 859 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 860 existing_state->invalidate_local(index); 861 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 862 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 863 existing_state->setup_phi_for_local(this, index); 864 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)); 865 } 866 } 867 } 868 869 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal"); 870 871 } else { 872 assert(false, "stack or locks not matching (invalid bytecodes)"); 873 return false; 874 } 875 876 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id())); 877 878 return true; 879 } 880 881 882 #ifndef PRODUCT 883 void BlockBegin::print_block() { 884 InstructionPrinter ip; 885 print_block(ip, false); 886 } 887 888 889 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) { 890 ip.print_instr(this); tty->cr(); 891 ip.print_stack(this->state()); tty->cr(); 892 ip.print_inline_level(this); 893 ip.print_head(); 894 for (Instruction* n = next(); n != NULL; n = n->next()) { 895 if (!live_only || n->is_pinned() || n->use_count() > 0) { 896 ip.print_line(n); 897 } 898 } 899 tty->cr(); 900 } 901 #endif // PRODUCT 902 903 904 // Implementation of BlockList 905 906 void BlockList::iterate_forward (BlockClosure* closure) { 907 const int l = length(); 908 for (int i = 0; i < l; i++) closure->block_do(at(i)); 909 } 910 911 912 void BlockList::iterate_backward(BlockClosure* closure) { 913 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i)); 914 } 915 916 917 void BlockList::blocks_do(void f(BlockBegin*)) { 918 for (int i = length() - 1; i >= 0; i--) f(at(i)); 919 } 920 921 922 void BlockList::values_do(void f(Value*)) { 923 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f); 924 } 925 926 927 #ifndef PRODUCT 928 void BlockList::print(bool cfg_only, bool live_only) { 929 InstructionPrinter ip; 930 for (int i = 0; i < length(); i++) { 931 BlockBegin* block = at(i); 932 if (cfg_only) { 933 ip.print_instr(block); tty->cr(); 934 } else { 935 block->print_block(ip, live_only); 936 } 937 } 938 } 939 #endif // PRODUCT 940 941 942 // Implementation of BlockEnd 943 944 void BlockEnd::set_begin(BlockBegin* begin) { 945 BlockList* sux = NULL; 946 if (begin != NULL) { 947 sux = begin->successors(); 948 } else if (_begin != NULL) { 949 // copy our sux list 950 BlockList* sux = new BlockList(_begin->number_of_sux()); 951 for (int i = 0; i < _begin->number_of_sux(); i++) { 952 sux->append(_begin->sux_at(i)); 953 } 954 } 955 _sux = sux; 956 _begin = begin; 957 } 958 959 960 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 961 substitute(*_sux, old_sux, new_sux); 962 } 963 964 965 void BlockEnd::other_values_do(void f(Value*)) { 966 if (state_before() != NULL) state_before()->values_do(f); 967 } 968 969 970 // Implementation of Phi 971 972 // Normal phi functions take their operands from the last instruction of the 973 // predecessor. Special handling is needed for xhanlder entries because there 974 // the state of arbitrary instructions are needed. 975 976 Value Phi::operand_at(int i) const { 977 ValueStack* state; 978 if (_block->is_set(BlockBegin::exception_entry_flag)) { 979 state = _block->exception_state_at(i); 980 } else { 981 state = _block->pred_at(i)->end()->state(); 982 } 983 assert(state != NULL, ""); 984 985 if (is_local()) { 986 return state->local_at(local_index()); 987 } else { 988 return state->stack_at(stack_index()); 989 } 990 } 991 992 993 int Phi::operand_count() const { 994 if (_block->is_set(BlockBegin::exception_entry_flag)) { 995 return _block->number_of_exception_states(); 996 } else { 997 return _block->number_of_preds(); 998 } 999 } 1000 1001 1002 // Implementation of Throw 1003 1004 void Throw::state_values_do(void f(Value*)) { 1005 BlockEnd::state_values_do(f); 1006 }