1 /* 2 * Copyright (c) 1999, 2012, 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 37 int 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 46 Instruction::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 62 Instruction::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 77 void 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()->jvmti_can_access_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 87 Instruction* 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 98 void 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 } 106 107 108 #ifndef PRODUCT 109 void Instruction::check_state(ValueStack* state) { 110 if (state != NULL) { 111 state->verify(); 112 } 113 } 114 115 116 void Instruction::print() { 117 InstructionPrinter ip; 118 print(ip); 119 } 120 121 122 void Instruction::print_line() { 123 InstructionPrinter ip; 124 ip.print_line(this); 125 } 126 127 128 void Instruction::print(InstructionPrinter& ip) { 129 ip.print_head(); 130 ip.print_line(this); 131 tty->cr(); 132 } 133 #endif // PRODUCT 134 135 136 // perform constant and interval tests on index value 137 bool AccessIndexed::compute_needs_range_check() { 138 139 if (length()) { 140 141 Constant* clength = length()->as_Constant(); 142 Constant* cindex = index()->as_Constant(); 143 if (clength && cindex) { 144 IntConstant* l = clength->type()->as_IntConstant(); 145 IntConstant* i = cindex->type()->as_IntConstant(); 146 if (l && i && i->value() < l->value() && i->value() >= 0) { 147 return false; 148 } 149 } 150 } 151 152 if (!this->check_flag(NeedsRangeCheckFlag)) { 153 return false; 154 } 155 156 return true; 157 } 158 159 160 ciType* Local::exact_type() const { 161 ciType* type = declared_type(); 162 163 // for primitive arrays, the declared type is the exact type 164 if (type->is_type_array_klass()) { 165 return type; 166 } else if (type->is_instance_klass()) { 167 ciInstanceKlass* ik = (ciInstanceKlass*)type; 168 if (ik->is_loaded() && ik->is_final() && !ik->is_interface()) { 169 return type; 170 } 171 } else if (type->is_obj_array_klass()) { 172 ciObjArrayKlass* oak = (ciObjArrayKlass*)type; 173 ciType* base = oak->base_element_type(); 174 if (base->is_instance_klass()) { 175 ciInstanceKlass* ik = base->as_instance_klass(); 176 if (ik->is_loaded() && ik->is_final()) { 177 return type; 178 } 179 } else if (base->is_primitive_type()) { 180 return type; 181 } 182 } 183 return NULL; 184 } 185 186 ciType* Constant::exact_type() const { 187 if (type()->is_object()) { 188 return type()->as_ObjectType()->exact_type(); 189 } 190 return NULL; 191 } 192 193 ciType* LoadIndexed::exact_type() const { 194 ciType* array_type = array()->exact_type(); 195 if (array_type == NULL) { 196 return NULL; 197 } 198 assert(array_type->is_array_klass(), "what else?"); 199 ciArrayKlass* ak = (ciArrayKlass*)array_type; 200 201 if (ak->element_type()->is_instance_klass()) { 202 ciInstanceKlass* ik = (ciInstanceKlass*)ak->element_type(); 203 if (ik->is_loaded() && ik->is_final()) { 204 return ik; 205 } 206 } 207 return NULL; 208 } 209 210 211 ciType* LoadIndexed::declared_type() const { 212 ciType* array_type = array()->declared_type(); 213 if (array_type == NULL || !array_type->is_loaded()) { 214 return NULL; 215 } 216 assert(array_type->is_array_klass(), "what else?"); 217 ciArrayKlass* ak = (ciArrayKlass*)array_type; 218 return ak->element_type(); 219 } 220 221 222 ciType* LoadField::declared_type() const { 223 return field()->type(); 224 } 225 226 227 ciType* LoadField::exact_type() const { 228 ciType* type = declared_type(); 229 // for primitive arrays, the declared type is the exact type 230 if (type->is_type_array_klass()) { 231 return type; 232 } 233 if (type->is_instance_klass()) { 234 ciInstanceKlass* ik = (ciInstanceKlass*)type; 235 if (ik->is_loaded() && ik->is_final()) { 236 return type; 237 } 238 } 239 return NULL; 240 } 241 242 243 ciType* NewTypeArray::exact_type() const { 244 return ciTypeArrayKlass::make(elt_type()); 245 } 246 247 ciType* NewObjectArray::exact_type() const { 248 return ciObjArrayKlass::make(klass()); 249 } 250 251 ciType* NewArray::declared_type() const { 252 return exact_type(); 253 } 254 255 ciType* NewInstance::exact_type() const { 256 return klass(); 257 } 258 259 ciType* NewInstance::declared_type() const { 260 return exact_type(); 261 } 262 263 ciType* CheckCast::declared_type() const { 264 return klass(); 265 } 266 267 ciType* CheckCast::exact_type() const { 268 if (klass()->is_instance_klass()) { 269 ciInstanceKlass* ik = (ciInstanceKlass*)klass(); 270 if (ik->is_loaded() && ik->is_final()) { 271 return ik; 272 } 273 } 274 return NULL; 275 } 276 277 // Implementation of ArithmeticOp 278 279 bool ArithmeticOp::is_commutative() const { 280 switch (op()) { 281 case Bytecodes::_iadd: // fall through 282 case Bytecodes::_ladd: // fall through 283 case Bytecodes::_fadd: // fall through 284 case Bytecodes::_dadd: // fall through 285 case Bytecodes::_imul: // fall through 286 case Bytecodes::_lmul: // fall through 287 case Bytecodes::_fmul: // fall through 288 case Bytecodes::_dmul: return true; 289 } 290 return false; 291 } 292 293 294 bool ArithmeticOp::can_trap() const { 295 switch (op()) { 296 case Bytecodes::_idiv: // fall through 297 case Bytecodes::_ldiv: // fall through 298 case Bytecodes::_irem: // fall through 299 case Bytecodes::_lrem: return true; 300 } 301 return false; 302 } 303 304 305 // Implementation of LogicOp 306 307 bool LogicOp::is_commutative() const { 308 #ifdef ASSERT 309 switch (op()) { 310 case Bytecodes::_iand: // fall through 311 case Bytecodes::_land: // fall through 312 case Bytecodes::_ior : // fall through 313 case Bytecodes::_lor : // fall through 314 case Bytecodes::_ixor: // fall through 315 case Bytecodes::_lxor: break; 316 default : ShouldNotReachHere(); 317 } 318 #endif 319 // all LogicOps are commutative 320 return true; 321 } 322 323 324 // Implementation of IfOp 325 326 bool IfOp::is_commutative() const { 327 return cond() == eql || cond() == neq; 328 } 329 330 331 // Implementation of StateSplit 332 333 void StateSplit::substitute(BlockList& list, BlockBegin* old_block, BlockBegin* new_block) { 334 NOT_PRODUCT(bool assigned = false;) 335 for (int i = 0; i < list.length(); i++) { 336 BlockBegin** b = list.adr_at(i); 337 if (*b == old_block) { 338 *b = new_block; 339 NOT_PRODUCT(assigned = true;) 340 } 341 } 342 assert(assigned == true, "should have assigned at least once"); 343 } 344 345 346 IRScope* StateSplit::scope() const { 347 return _state->scope(); 348 } 349 350 351 void StateSplit::state_values_do(ValueVisitor* f) { 352 Instruction::state_values_do(f); 353 if (state() != NULL) state()->values_do(f); 354 } 355 356 357 void BlockBegin::state_values_do(ValueVisitor* f) { 358 StateSplit::state_values_do(f); 359 360 if (is_set(BlockBegin::exception_entry_flag)) { 361 for (int i = 0; i < number_of_exception_states(); i++) { 362 exception_state_at(i)->values_do(f); 363 } 364 } 365 } 366 367 368 // Implementation of Invoke 369 370 371 Invoke::Invoke(Bytecodes::Code code, ValueType* result_type, Value recv, Values* args, 372 int vtable_index, ciMethod* target, ValueStack* state_before) 373 : StateSplit(result_type, state_before) 374 , _code(code) 375 , _recv(recv) 376 , _args(args) 377 , _vtable_index(vtable_index) 378 , _target(target) 379 { 380 set_flag(TargetIsLoadedFlag, target->is_loaded()); 381 set_flag(TargetIsFinalFlag, target_is_loaded() && target->is_final_method()); 382 set_flag(TargetIsStrictfpFlag, target_is_loaded() && target->is_strict()); 383 384 assert(args != NULL, "args must exist"); 385 #ifdef ASSERT 386 AssertValues assert_value; 387 values_do(&assert_value); 388 #endif 389 390 // provide an initial guess of signature size. 391 _signature = new BasicTypeList(number_of_arguments() + (has_receiver() ? 1 : 0)); 392 if (has_receiver()) { 393 _signature->append(as_BasicType(receiver()->type())); 394 } 395 for (int i = 0; i < number_of_arguments(); i++) { 396 ValueType* t = argument_at(i)->type(); 397 BasicType bt = as_BasicType(t); 398 _signature->append(bt); 399 } 400 } 401 402 403 void Invoke::state_values_do(ValueVisitor* f) { 404 StateSplit::state_values_do(f); 405 if (state_before() != NULL) state_before()->values_do(f); 406 if (state() != NULL) state()->values_do(f); 407 } 408 409 ciType* Invoke::declared_type() const { 410 ciType *t = _target->signature()->return_type(); 411 assert(t->basic_type() != T_VOID, "need return value of void method?"); 412 return t; 413 } 414 415 // Implementation of Contant 416 intx Constant::hash() const { 417 if (state_before() == NULL) { 418 switch (type()->tag()) { 419 case intTag: 420 return HASH2(name(), type()->as_IntConstant()->value()); 421 case addressTag: 422 return HASH2(name(), type()->as_AddressConstant()->value()); 423 case longTag: 424 { 425 jlong temp = type()->as_LongConstant()->value(); 426 return HASH3(name(), high(temp), low(temp)); 427 } 428 case floatTag: 429 return HASH2(name(), jint_cast(type()->as_FloatConstant()->value())); 430 case doubleTag: 431 { 432 jlong temp = jlong_cast(type()->as_DoubleConstant()->value()); 433 return HASH3(name(), high(temp), low(temp)); 434 } 435 case objectTag: 436 assert(type()->as_ObjectType()->is_loaded(), "can't handle unloaded values"); 437 return HASH2(name(), type()->as_ObjectType()->constant_value()); 438 case metaDataTag: 439 assert(type()->as_MetadataType()->is_loaded(), "can't handle unloaded values"); 440 return HASH2(name(), type()->as_MetadataType()->constant_value()); 441 default: 442 ShouldNotReachHere(); 443 } 444 } 445 return 0; 446 } 447 448 bool Constant::is_equal(Value v) const { 449 if (v->as_Constant() == NULL) return false; 450 451 switch (type()->tag()) { 452 case intTag: 453 { 454 IntConstant* t1 = type()->as_IntConstant(); 455 IntConstant* t2 = v->type()->as_IntConstant(); 456 return (t1 != NULL && t2 != NULL && 457 t1->value() == t2->value()); 458 } 459 case longTag: 460 { 461 LongConstant* t1 = type()->as_LongConstant(); 462 LongConstant* t2 = v->type()->as_LongConstant(); 463 return (t1 != NULL && t2 != NULL && 464 t1->value() == t2->value()); 465 } 466 case floatTag: 467 { 468 FloatConstant* t1 = type()->as_FloatConstant(); 469 FloatConstant* t2 = v->type()->as_FloatConstant(); 470 return (t1 != NULL && t2 != NULL && 471 jint_cast(t1->value()) == jint_cast(t2->value())); 472 } 473 case doubleTag: 474 { 475 DoubleConstant* t1 = type()->as_DoubleConstant(); 476 DoubleConstant* t2 = v->type()->as_DoubleConstant(); 477 return (t1 != NULL && t2 != NULL && 478 jlong_cast(t1->value()) == jlong_cast(t2->value())); 479 } 480 case objectTag: 481 { 482 ObjectType* t1 = type()->as_ObjectType(); 483 ObjectType* t2 = v->type()->as_ObjectType(); 484 return (t1 != NULL && t2 != NULL && 485 t1->is_loaded() && t2->is_loaded() && 486 t1->constant_value() == t2->constant_value()); 487 } 488 case metaDataTag: 489 { 490 MetadataType* t1 = type()->as_MetadataType(); 491 MetadataType* t2 = v->type()->as_MetadataType(); 492 return (t1 != NULL && t2 != NULL && 493 t1->is_loaded() && t2->is_loaded() && 494 t1->constant_value() == t2->constant_value()); 495 } 496 } 497 return false; 498 } 499 500 Constant::CompareResult Constant::compare(Instruction::Condition cond, Value right) const { 501 Constant* rc = right->as_Constant(); 502 // other is not a constant 503 if (rc == NULL) return not_comparable; 504 505 ValueType* lt = type(); 506 ValueType* rt = rc->type(); 507 // different types 508 if (lt->base() != rt->base()) return not_comparable; 509 switch (lt->tag()) { 510 case intTag: { 511 int x = lt->as_IntConstant()->value(); 512 int y = rt->as_IntConstant()->value(); 513 switch (cond) { 514 case If::eql: return x == y ? cond_true : cond_false; 515 case If::neq: return x != y ? cond_true : cond_false; 516 case If::lss: return x < y ? cond_true : cond_false; 517 case If::leq: return x <= y ? cond_true : cond_false; 518 case If::gtr: return x > y ? cond_true : cond_false; 519 case If::geq: return x >= y ? cond_true : cond_false; 520 } 521 break; 522 } 523 case longTag: { 524 jlong x = lt->as_LongConstant()->value(); 525 jlong y = rt->as_LongConstant()->value(); 526 switch (cond) { 527 case If::eql: return x == y ? cond_true : cond_false; 528 case If::neq: return x != y ? cond_true : cond_false; 529 case If::lss: return x < y ? cond_true : cond_false; 530 case If::leq: return x <= y ? cond_true : cond_false; 531 case If::gtr: return x > y ? cond_true : cond_false; 532 case If::geq: return x >= y ? cond_true : cond_false; 533 } 534 break; 535 } 536 case objectTag: { 537 ciObject* xvalue = lt->as_ObjectType()->constant_value(); 538 ciObject* yvalue = rt->as_ObjectType()->constant_value(); 539 assert(xvalue != NULL && yvalue != NULL, "not constants"); 540 if (xvalue->is_loaded() && yvalue->is_loaded()) { 541 switch (cond) { 542 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 543 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 544 } 545 } 546 break; 547 } 548 case metaDataTag: { 549 ciMetadata* xvalue = lt->as_MetadataType()->constant_value(); 550 ciMetadata* yvalue = rt->as_MetadataType()->constant_value(); 551 assert(xvalue != NULL && yvalue != NULL, "not constants"); 552 if (xvalue->is_loaded() && yvalue->is_loaded()) { 553 switch (cond) { 554 case If::eql: return xvalue == yvalue ? cond_true : cond_false; 555 case If::neq: return xvalue != yvalue ? cond_true : cond_false; 556 } 557 } 558 break; 559 } 560 } 561 return not_comparable; 562 } 563 564 565 // Implementation of BlockBegin 566 567 void BlockBegin::set_end(BlockEnd* end) { 568 assert(end != NULL, "should not reset block end to NULL"); 569 if (end == _end) { 570 return; 571 } 572 clear_end(); 573 574 // Set the new end 575 _end = end; 576 577 _successors.clear(); 578 // Now reset successors list based on BlockEnd 579 for (int i = 0; i < end->number_of_sux(); i++) { 580 BlockBegin* sux = end->sux_at(i); 581 _successors.append(sux); 582 sux->_predecessors.append(this); 583 } 584 _end->set_begin(this); 585 } 586 587 588 void BlockBegin::clear_end() { 589 // Must make the predecessors/successors match up with the 590 // BlockEnd's notion. 591 if (_end != NULL) { 592 // disconnect from the old end 593 _end->set_begin(NULL); 594 595 // disconnect this block from it's current successors 596 for (int i = 0; i < _successors.length(); i++) { 597 _successors.at(i)->remove_predecessor(this); 598 } 599 _end = NULL; 600 } 601 } 602 603 604 void BlockBegin::disconnect_edge(BlockBegin* from, BlockBegin* to) { 605 // disconnect any edges between from and to 606 #ifndef PRODUCT 607 if (PrintIR && Verbose) { 608 tty->print_cr("Disconnected edge B%d -> B%d", from->block_id(), to->block_id()); 609 } 610 #endif 611 for (int s = 0; s < from->number_of_sux();) { 612 BlockBegin* sux = from->sux_at(s); 613 if (sux == to) { 614 int index = sux->_predecessors.index_of(from); 615 if (index >= 0) { 616 sux->_predecessors.remove_at(index); 617 } 618 from->_successors.remove_at(s); 619 } else { 620 s++; 621 } 622 } 623 } 624 625 626 void BlockBegin::disconnect_from_graph() { 627 // disconnect this block from all other blocks 628 for (int p = 0; p < number_of_preds(); p++) { 629 pred_at(p)->remove_successor(this); 630 } 631 for (int s = 0; s < number_of_sux(); s++) { 632 sux_at(s)->remove_predecessor(this); 633 } 634 } 635 636 void BlockBegin::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 637 // modify predecessors before substituting successors 638 for (int i = 0; i < number_of_sux(); i++) { 639 if (sux_at(i) == old_sux) { 640 // remove old predecessor before adding new predecessor 641 // otherwise there is a dead predecessor in the list 642 new_sux->remove_predecessor(old_sux); 643 new_sux->add_predecessor(this); 644 } 645 } 646 old_sux->remove_predecessor(this); 647 end()->substitute_sux(old_sux, new_sux); 648 } 649 650 651 652 // In general it is not possible to calculate a value for the field "depth_first_number" 653 // of the inserted block, without recomputing the values of the other blocks 654 // in the CFG. Therefore the value of "depth_first_number" in BlockBegin becomes meaningless. 655 BlockBegin* BlockBegin::insert_block_between(BlockBegin* sux) { 656 int bci = sux->bci(); 657 // critical edge splitting may introduce a goto after a if and array 658 // bound check elimination may insert a predicate between the if and 659 // goto. The bci of the goto can't be the one of the if otherwise 660 // the state and bci are inconsistent and a deoptimization triggered 661 // by the predicate would lead to incorrect execution/a crash. 662 BlockBegin* new_sux = new BlockBegin(bci); 663 664 // mark this block (special treatment when block order is computed) 665 new_sux->set(critical_edge_split_flag); 666 667 // This goto is not a safepoint. 668 Goto* e = new Goto(sux, false); 669 new_sux->set_next(e, bci); 670 new_sux->set_end(e); 671 // setup states 672 ValueStack* s = end()->state(); 673 new_sux->set_state(s->copy(s->kind(), bci)); 674 e->set_state(s->copy(s->kind(), bci)); 675 assert(new_sux->state()->locals_size() == s->locals_size(), "local size mismatch!"); 676 assert(new_sux->state()->stack_size() == s->stack_size(), "stack size mismatch!"); 677 assert(new_sux->state()->locks_size() == s->locks_size(), "locks size mismatch!"); 678 679 // link predecessor to new block 680 end()->substitute_sux(sux, new_sux); 681 682 // The ordering needs to be the same, so remove the link that the 683 // set_end call above added and substitute the new_sux for this 684 // block. 685 sux->remove_predecessor(new_sux); 686 687 // the successor could be the target of a switch so it might have 688 // multiple copies of this predecessor, so substitute the new_sux 689 // for the first and delete the rest. 690 bool assigned = false; 691 BlockList& list = sux->_predecessors; 692 for (int i = 0; i < list.length(); i++) { 693 BlockBegin** b = list.adr_at(i); 694 if (*b == this) { 695 if (assigned) { 696 list.remove_at(i); 697 // reprocess this index 698 i--; 699 } else { 700 assigned = true; 701 *b = new_sux; 702 } 703 // link the new block back to it's predecessors. 704 new_sux->add_predecessor(this); 705 } 706 } 707 assert(assigned == true, "should have assigned at least once"); 708 return new_sux; 709 } 710 711 712 void BlockBegin::remove_successor(BlockBegin* pred) { 713 int idx; 714 while ((idx = _successors.index_of(pred)) >= 0) { 715 _successors.remove_at(idx); 716 } 717 } 718 719 720 void BlockBegin::add_predecessor(BlockBegin* pred) { 721 _predecessors.append(pred); 722 } 723 724 725 void BlockBegin::remove_predecessor(BlockBegin* pred) { 726 int idx; 727 while ((idx = _predecessors.index_of(pred)) >= 0) { 728 _predecessors.remove_at(idx); 729 } 730 } 731 732 733 void BlockBegin::add_exception_handler(BlockBegin* b) { 734 assert(b != NULL && (b->is_set(exception_entry_flag)), "exception handler must exist"); 735 // add only if not in the list already 736 if (!_exception_handlers.contains(b)) _exception_handlers.append(b); 737 } 738 739 int BlockBegin::add_exception_state(ValueStack* state) { 740 assert(is_set(exception_entry_flag), "only for xhandlers"); 741 if (_exception_states == NULL) { 742 _exception_states = new ValueStackStack(4); 743 } 744 _exception_states->append(state); 745 return _exception_states->length() - 1; 746 } 747 748 749 void BlockBegin::iterate_preorder(boolArray& mark, BlockClosure* closure) { 750 if (!mark.at(block_id())) { 751 mark.at_put(block_id(), true); 752 closure->block_do(this); 753 BlockEnd* e = end(); // must do this after block_do because block_do may change it! 754 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_preorder(mark, closure); } 755 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_preorder(mark, closure); } 756 } 757 } 758 759 760 void BlockBegin::iterate_postorder(boolArray& mark, BlockClosure* closure) { 761 if (!mark.at(block_id())) { 762 mark.at_put(block_id(), true); 763 BlockEnd* e = end(); 764 { for (int i = number_of_exception_handlers() - 1; i >= 0; i--) exception_handler_at(i)->iterate_postorder(mark, closure); } 765 { for (int i = e->number_of_sux () - 1; i >= 0; i--) e->sux_at (i)->iterate_postorder(mark, closure); } 766 closure->block_do(this); 767 } 768 } 769 770 771 void BlockBegin::iterate_preorder(BlockClosure* closure) { 772 boolArray mark(number_of_blocks(), false); 773 iterate_preorder(mark, closure); 774 } 775 776 777 void BlockBegin::iterate_postorder(BlockClosure* closure) { 778 boolArray mark(number_of_blocks(), false); 779 iterate_postorder(mark, closure); 780 } 781 782 783 void BlockBegin::block_values_do(ValueVisitor* f) { 784 for (Instruction* n = this; n != NULL; n = n->next()) n->values_do(f); 785 } 786 787 788 #ifndef PRODUCT 789 #define TRACE_PHI(code) if (PrintPhiFunctions) { code; } 790 #else 791 #define TRACE_PHI(coce) 792 #endif 793 794 795 bool BlockBegin::try_merge(ValueStack* new_state) { 796 TRACE_PHI(tty->print_cr("********** try_merge for block B%d", block_id())); 797 798 // local variables used for state iteration 799 int index; 800 Value new_value, existing_value; 801 802 ValueStack* existing_state = state(); 803 if (existing_state == NULL) { 804 TRACE_PHI(tty->print_cr("first call of try_merge for this block")); 805 806 if (is_set(BlockBegin::was_visited_flag)) { 807 // this actually happens for complicated jsr/ret structures 808 return false; // BAILOUT in caller 809 } 810 811 // copy state because it is altered 812 new_state = new_state->copy(ValueStack::BlockBeginState, bci()); 813 814 // Use method liveness to invalidate dead locals 815 MethodLivenessResult liveness = new_state->scope()->method()->liveness_at_bci(bci()); 816 if (liveness.is_valid()) { 817 assert((int)liveness.size() == new_state->locals_size(), "error in use of liveness"); 818 819 for_each_local_value(new_state, index, new_value) { 820 if (!liveness.at(index) || new_value->type()->is_illegal()) { 821 new_state->invalidate_local(index); 822 TRACE_PHI(tty->print_cr("invalidating dead local %d", index)); 823 } 824 } 825 } 826 827 if (is_set(BlockBegin::parser_loop_header_flag)) { 828 TRACE_PHI(tty->print_cr("loop header block, initializing phi functions")); 829 830 for_each_stack_value(new_state, index, new_value) { 831 new_state->setup_phi_for_stack(this, index); 832 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)); 833 } 834 835 BitMap requires_phi_function = new_state->scope()->requires_phi_function(); 836 837 for_each_local_value(new_state, index, new_value) { 838 bool requires_phi = requires_phi_function.at(index) || (new_value->type()->is_double_word() && requires_phi_function.at(index + 1)); 839 if (requires_phi || !SelectivePhiFunctions) { 840 new_state->setup_phi_for_local(this, index); 841 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)); 842 } 843 } 844 } 845 846 // initialize state of block 847 set_state(new_state); 848 849 } else if (existing_state->is_same(new_state)) { 850 TRACE_PHI(tty->print_cr("exisiting state found")); 851 852 assert(existing_state->scope() == new_state->scope(), "not matching"); 853 assert(existing_state->locals_size() == new_state->locals_size(), "not matching"); 854 assert(existing_state->stack_size() == new_state->stack_size(), "not matching"); 855 856 if (is_set(BlockBegin::was_visited_flag)) { 857 TRACE_PHI(tty->print_cr("loop header block, phis must be present")); 858 859 if (!is_set(BlockBegin::parser_loop_header_flag)) { 860 // this actually happens for complicated jsr/ret structures 861 return false; // BAILOUT in caller 862 } 863 864 for_each_local_value(existing_state, index, existing_value) { 865 Value new_value = new_state->local_at(index); 866 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 867 // The old code invalidated the phi function here 868 // Because dead locals are replaced with NULL, this is a very rare case now, so simply bail out 869 return false; // BAILOUT in caller 870 } 871 } 872 873 #ifdef ASSERT 874 // check that all necessary phi functions are present 875 for_each_stack_value(existing_state, index, existing_value) { 876 assert(existing_value->as_Phi() != NULL && existing_value->as_Phi()->block() == this, "phi function required"); 877 } 878 for_each_local_value(existing_state, index, existing_value) { 879 assert(existing_value == new_state->local_at(index) || (existing_value->as_Phi() != NULL && existing_value->as_Phi()->as_Phi()->block() == this), "phi function required"); 880 } 881 #endif 882 883 } else { 884 TRACE_PHI(tty->print_cr("creating phi functions on demand")); 885 886 // create necessary phi functions for stack 887 for_each_stack_value(existing_state, index, existing_value) { 888 Value new_value = new_state->stack_at(index); 889 Phi* existing_phi = existing_value->as_Phi(); 890 891 if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 892 existing_state->setup_phi_for_stack(this, index); 893 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)); 894 } 895 } 896 897 // create necessary phi functions for locals 898 for_each_local_value(existing_state, index, existing_value) { 899 Value new_value = new_state->local_at(index); 900 Phi* existing_phi = existing_value->as_Phi(); 901 902 if (new_value == NULL || new_value->type()->tag() != existing_value->type()->tag()) { 903 existing_state->invalidate_local(index); 904 TRACE_PHI(tty->print_cr("invalidating local %d because of type mismatch", index)); 905 } else if (new_value != existing_value && (existing_phi == NULL || existing_phi->block() != this)) { 906 existing_state->setup_phi_for_local(this, index); 907 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)); 908 } 909 } 910 } 911 912 assert(existing_state->caller_state() == new_state->caller_state(), "caller states must be equal"); 913 914 } else { 915 assert(false, "stack or locks not matching (invalid bytecodes)"); 916 return false; 917 } 918 919 TRACE_PHI(tty->print_cr("********** try_merge for block B%d successful", block_id())); 920 921 return true; 922 } 923 924 925 #ifndef PRODUCT 926 void BlockBegin::print_block() { 927 InstructionPrinter ip; 928 print_block(ip, false); 929 } 930 931 932 void BlockBegin::print_block(InstructionPrinter& ip, bool live_only) { 933 ip.print_instr(this); tty->cr(); 934 ip.print_stack(this->state()); tty->cr(); 935 ip.print_inline_level(this); 936 ip.print_head(); 937 for (Instruction* n = next(); n != NULL; n = n->next()) { 938 if (!live_only || n->is_pinned() || n->use_count() > 0) { 939 ip.print_line(n); 940 } 941 } 942 tty->cr(); 943 } 944 #endif // PRODUCT 945 946 947 // Implementation of BlockList 948 949 void BlockList::iterate_forward (BlockClosure* closure) { 950 const int l = length(); 951 for (int i = 0; i < l; i++) closure->block_do(at(i)); 952 } 953 954 955 void BlockList::iterate_backward(BlockClosure* closure) { 956 for (int i = length() - 1; i >= 0; i--) closure->block_do(at(i)); 957 } 958 959 960 void BlockList::blocks_do(void f(BlockBegin*)) { 961 for (int i = length() - 1; i >= 0; i--) f(at(i)); 962 } 963 964 965 void BlockList::values_do(ValueVisitor* f) { 966 for (int i = length() - 1; i >= 0; i--) at(i)->block_values_do(f); 967 } 968 969 970 #ifndef PRODUCT 971 void BlockList::print(bool cfg_only, bool live_only) { 972 InstructionPrinter ip; 973 for (int i = 0; i < length(); i++) { 974 BlockBegin* block = at(i); 975 if (cfg_only) { 976 ip.print_instr(block); tty->cr(); 977 } else { 978 block->print_block(ip, live_only); 979 } 980 } 981 } 982 #endif // PRODUCT 983 984 985 // Implementation of BlockEnd 986 987 void BlockEnd::set_begin(BlockBegin* begin) { 988 BlockList* sux = NULL; 989 if (begin != NULL) { 990 sux = begin->successors(); 991 } else if (this->begin() != NULL) { 992 // copy our sux list 993 BlockList* sux = new BlockList(this->begin()->number_of_sux()); 994 for (int i = 0; i < this->begin()->number_of_sux(); i++) { 995 sux->append(this->begin()->sux_at(i)); 996 } 997 } 998 _sux = sux; 999 } 1000 1001 1002 void BlockEnd::substitute_sux(BlockBegin* old_sux, BlockBegin* new_sux) { 1003 substitute(*_sux, old_sux, new_sux); 1004 } 1005 1006 1007 // Implementation of Phi 1008 1009 // Normal phi functions take their operands from the last instruction of the 1010 // predecessor. Special handling is needed for xhanlder entries because there 1011 // the state of arbitrary instructions are needed. 1012 1013 Value Phi::operand_at(int i) const { 1014 ValueStack* state; 1015 if (_block->is_set(BlockBegin::exception_entry_flag)) { 1016 state = _block->exception_state_at(i); 1017 } else { 1018 state = _block->pred_at(i)->end()->state(); 1019 } 1020 assert(state != NULL, ""); 1021 1022 if (is_local()) { 1023 return state->local_at(local_index()); 1024 } else { 1025 return state->stack_at(stack_index()); 1026 } 1027 } 1028 1029 1030 int Phi::operand_count() const { 1031 if (_block->is_set(BlockBegin::exception_entry_flag)) { 1032 return _block->number_of_exception_states(); 1033 } else { 1034 return _block->number_of_preds(); 1035 } 1036 } 1037 1038 #ifdef ASSERT 1039 // Constructor of Assert 1040 Assert::Assert(Value x, Condition cond, bool unordered_is_true, Value y) : Instruction(illegalType) 1041 , _x(x) 1042 , _cond(cond) 1043 , _y(y) 1044 { 1045 set_flag(UnorderedIsTrueFlag, unordered_is_true); 1046 assert(x->type()->tag() == y->type()->tag(), "types must match"); 1047 pin(); 1048 1049 stringStream strStream; 1050 Compilation::current()->method()->print_name(&strStream); 1051 1052 stringStream strStream1; 1053 InstructionPrinter ip1(1, &strStream1); 1054 ip1.print_instr(x); 1055 1056 stringStream strStream2; 1057 InstructionPrinter ip2(1, &strStream2); 1058 ip2.print_instr(y); 1059 1060 stringStream ss; 1061 ss.print("Assertion %s %s %s in method %s", strStream1.as_string(), ip2.cond_name(cond), strStream2.as_string(), strStream.as_string()); 1062 1063 _message = ss.as_string(); 1064 } 1065 #endif 1066 1067 void RangeCheckPredicate::check_state() { 1068 assert(state()->kind() != ValueStack::EmptyExceptionState && state()->kind() != ValueStack::ExceptionState, "will deopt with empty state"); 1069 } 1070 1071 void ProfileInvoke::state_values_do(ValueVisitor* f) { 1072 if (state() != NULL) state()->values_do(f); 1073 }