1 /* 2 * Copyright (c) 2000, 2023, 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 "ci/ciConstant.hpp" 27 #include "ci/ciField.hpp" 28 #include "ci/ciMethod.hpp" 29 #include "ci/ciMethodData.hpp" 30 #include "ci/ciObjArrayKlass.hpp" 31 #include "ci/ciStreams.hpp" 32 #include "ci/ciTypeArrayKlass.hpp" 33 #include "ci/ciTypeFlow.hpp" 34 #include "compiler/compileLog.hpp" 35 #include "interpreter/bytecode.hpp" 36 #include "interpreter/bytecodes.hpp" 37 #include "memory/allocation.inline.hpp" 38 #include "memory/resourceArea.hpp" 39 #include "oops/oop.inline.hpp" 40 #include "opto/compile.hpp" 41 #include "opto/node.hpp" 42 #include "runtime/deoptimization.hpp" 43 #include "utilities/growableArray.hpp" 44 45 // ciTypeFlow::JsrSet 46 // 47 // A JsrSet represents some set of JsrRecords. This class 48 // is used to record a set of all jsr routines which we permit 49 // execution to return (ret) from. 50 // 51 // During abstract interpretation, JsrSets are used to determine 52 // whether two paths which reach a given block are unique, and 53 // should be cloned apart, or are compatible, and should merge 54 // together. 55 56 // ------------------------------------------------------------------ 57 // ciTypeFlow::JsrSet::JsrSet 58 59 // Allocate growable array storage in Arena. 60 ciTypeFlow::JsrSet::JsrSet(Arena* arena, int default_len) : _set(arena, default_len, 0, nullptr) { 61 assert(arena != nullptr, "invariant"); 62 } 63 64 // Allocate growable array storage in current ResourceArea. 65 ciTypeFlow::JsrSet::JsrSet(int default_len) : _set(default_len, 0, nullptr) {} 66 67 // ------------------------------------------------------------------ 68 // ciTypeFlow::JsrSet::copy_into 69 void ciTypeFlow::JsrSet::copy_into(JsrSet* jsrs) { 70 int len = size(); 71 jsrs->_set.clear(); 72 for (int i = 0; i < len; i++) { 73 jsrs->_set.append(_set.at(i)); 74 } 75 } 76 77 // ------------------------------------------------------------------ 78 // ciTypeFlow::JsrSet::is_compatible_with 79 // 80 // !!!! MISGIVINGS ABOUT THIS... disregard 81 // 82 // Is this JsrSet compatible with some other JsrSet? 83 // 84 // In set-theoretic terms, a JsrSet can be viewed as a partial function 85 // from entry addresses to return addresses. Two JsrSets A and B are 86 // compatible iff 87 // 88 // For any x, 89 // A(x) defined and B(x) defined implies A(x) == B(x) 90 // 91 // Less formally, two JsrSets are compatible when they have identical 92 // return addresses for any entry addresses they share in common. 93 bool ciTypeFlow::JsrSet::is_compatible_with(JsrSet* other) { 94 // Walk through both sets in parallel. If the same entry address 95 // appears in both sets, then the return address must match for 96 // the sets to be compatible. 97 int size1 = size(); 98 int size2 = other->size(); 99 100 // Special case. If nothing is on the jsr stack, then there can 101 // be no ret. 102 if (size2 == 0) { 103 return true; 104 } else if (size1 != size2) { 105 return false; 106 } else { 107 for (int i = 0; i < size1; i++) { 108 JsrRecord* record1 = record_at(i); 109 JsrRecord* record2 = other->record_at(i); 110 if (record1->entry_address() != record2->entry_address() || 111 record1->return_address() != record2->return_address()) { 112 return false; 113 } 114 } 115 return true; 116 } 117 118 #if 0 119 int pos1 = 0; 120 int pos2 = 0; 121 int size1 = size(); 122 int size2 = other->size(); 123 while (pos1 < size1 && pos2 < size2) { 124 JsrRecord* record1 = record_at(pos1); 125 JsrRecord* record2 = other->record_at(pos2); 126 int entry1 = record1->entry_address(); 127 int entry2 = record2->entry_address(); 128 if (entry1 < entry2) { 129 pos1++; 130 } else if (entry1 > entry2) { 131 pos2++; 132 } else { 133 if (record1->return_address() == record2->return_address()) { 134 pos1++; 135 pos2++; 136 } else { 137 // These two JsrSets are incompatible. 138 return false; 139 } 140 } 141 } 142 // The two JsrSets agree. 143 return true; 144 #endif 145 } 146 147 // ------------------------------------------------------------------ 148 // ciTypeFlow::JsrSet::insert_jsr_record 149 // 150 // Insert the given JsrRecord into the JsrSet, maintaining the order 151 // of the set and replacing any element with the same entry address. 152 void ciTypeFlow::JsrSet::insert_jsr_record(JsrRecord* record) { 153 int len = size(); 154 int entry = record->entry_address(); 155 int pos = 0; 156 for ( ; pos < len; pos++) { 157 JsrRecord* current = record_at(pos); 158 if (entry == current->entry_address()) { 159 // Stomp over this entry. 160 _set.at_put(pos, record); 161 assert(size() == len, "must be same size"); 162 return; 163 } else if (entry < current->entry_address()) { 164 break; 165 } 166 } 167 168 // Insert the record into the list. 169 JsrRecord* swap = record; 170 JsrRecord* temp = nullptr; 171 for ( ; pos < len; pos++) { 172 temp = _set.at(pos); 173 _set.at_put(pos, swap); 174 swap = temp; 175 } 176 _set.append(swap); 177 assert(size() == len+1, "must be larger"); 178 } 179 180 // ------------------------------------------------------------------ 181 // ciTypeFlow::JsrSet::remove_jsr_record 182 // 183 // Remove the JsrRecord with the given return address from the JsrSet. 184 void ciTypeFlow::JsrSet::remove_jsr_record(int return_address) { 185 int len = size(); 186 for (int i = 0; i < len; i++) { 187 if (record_at(i)->return_address() == return_address) { 188 // We have found the proper entry. Remove it from the 189 // JsrSet and exit. 190 for (int j = i + 1; j < len ; j++) { 191 _set.at_put(j - 1, _set.at(j)); 192 } 193 _set.trunc_to(len - 1); 194 assert(size() == len-1, "must be smaller"); 195 return; 196 } 197 } 198 assert(false, "verify: returning from invalid subroutine"); 199 } 200 201 // ------------------------------------------------------------------ 202 // ciTypeFlow::JsrSet::apply_control 203 // 204 // Apply the effect of a control-flow bytecode on the JsrSet. The 205 // only bytecodes that modify the JsrSet are jsr and ret. 206 void ciTypeFlow::JsrSet::apply_control(ciTypeFlow* analyzer, 207 ciBytecodeStream* str, 208 ciTypeFlow::StateVector* state) { 209 Bytecodes::Code code = str->cur_bc(); 210 if (code == Bytecodes::_jsr) { 211 JsrRecord* record = 212 analyzer->make_jsr_record(str->get_dest(), str->next_bci()); 213 insert_jsr_record(record); 214 } else if (code == Bytecodes::_jsr_w) { 215 JsrRecord* record = 216 analyzer->make_jsr_record(str->get_far_dest(), str->next_bci()); 217 insert_jsr_record(record); 218 } else if (code == Bytecodes::_ret) { 219 Cell local = state->local(str->get_index()); 220 ciType* return_address = state->type_at(local); 221 assert(return_address->is_return_address(), "verify: wrong type"); 222 if (size() == 0) { 223 // Ret-state underflow: Hit a ret w/o any previous jsrs. Bail out. 224 // This can happen when a loop is inside a finally clause (4614060). 225 analyzer->record_failure("OSR in finally clause"); 226 return; 227 } 228 remove_jsr_record(return_address->as_return_address()->bci()); 229 } 230 } 231 232 #ifndef PRODUCT 233 // ------------------------------------------------------------------ 234 // ciTypeFlow::JsrSet::print_on 235 void ciTypeFlow::JsrSet::print_on(outputStream* st) const { 236 st->print("{ "); 237 int num_elements = size(); 238 if (num_elements > 0) { 239 int i = 0; 240 for( ; i < num_elements - 1; i++) { 241 _set.at(i)->print_on(st); 242 st->print(", "); 243 } 244 _set.at(i)->print_on(st); 245 st->print(" "); 246 } 247 st->print("}"); 248 } 249 #endif 250 251 // ciTypeFlow::StateVector 252 // 253 // A StateVector summarizes the type information at some point in 254 // the program. 255 256 // ------------------------------------------------------------------ 257 // ciTypeFlow::StateVector::type_meet 258 // 259 // Meet two types. 260 // 261 // The semi-lattice of types use by this analysis are modeled on those 262 // of the verifier. The lattice is as follows: 263 // 264 // top_type() >= all non-extremal types >= bottom_type 265 // and 266 // Every primitive type is comparable only with itself. The meet of 267 // reference types is determined by their kind: instance class, 268 // interface, or array class. The meet of two types of the same 269 // kind is their least common ancestor. The meet of two types of 270 // different kinds is always java.lang.Object. 271 ciType* ciTypeFlow::StateVector::type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer) { 272 assert(t1 != t2, "checked in caller"); 273 if (t1->equals(top_type())) { 274 return t2; 275 } else if (t2->equals(top_type())) { 276 return t1; 277 } else if (t1->is_primitive_type() || t2->is_primitive_type()) { 278 // Special case null_type. null_type meet any reference type T 279 // is T. null_type meet null_type is null_type. 280 if (t1->equals(null_type())) { 281 if (!t2->is_primitive_type() || t2->equals(null_type())) { 282 return t2; 283 } 284 } else if (t2->equals(null_type())) { 285 if (!t1->is_primitive_type()) { 286 return t1; 287 } 288 } 289 290 // At least one of the two types is a non-top primitive type. 291 // The other type is not equal to it. Fall to bottom. 292 return bottom_type(); 293 } else { 294 // Both types are non-top non-primitive types. That is, 295 // both types are either instanceKlasses or arrayKlasses. 296 ciKlass* object_klass = analyzer->env()->Object_klass(); 297 ciKlass* k1 = t1->as_klass(); 298 ciKlass* k2 = t2->as_klass(); 299 if (k1->equals(object_klass) || k2->equals(object_klass)) { 300 return object_klass; 301 } else if (!k1->is_loaded() || !k2->is_loaded()) { 302 // Unloaded classes fall to java.lang.Object at a merge. 303 return object_klass; 304 } else if (k1->is_interface() != k2->is_interface()) { 305 // When an interface meets a non-interface, we get Object; 306 // This is what the verifier does. 307 return object_klass; 308 } else if (k1->is_array_klass() || k2->is_array_klass()) { 309 // When an array meets a non-array, we get Object. 310 // When objArray meets typeArray, we also get Object. 311 // And when typeArray meets different typeArray, we again get Object. 312 // But when objArray meets objArray, we look carefully at element types. 313 if (k1->is_obj_array_klass() && k2->is_obj_array_klass()) { 314 // Meet the element types, then construct the corresponding array type. 315 ciKlass* elem1 = k1->as_obj_array_klass()->element_klass(); 316 ciKlass* elem2 = k2->as_obj_array_klass()->element_klass(); 317 ciKlass* elem = type_meet_internal(elem1, elem2, analyzer)->as_klass(); 318 // Do an easy shortcut if one type is a super of the other. 319 if (elem == elem1) { 320 assert(k1 == ciObjArrayKlass::make(elem), "shortcut is OK"); 321 return k1; 322 } else if (elem == elem2) { 323 assert(k2 == ciObjArrayKlass::make(elem), "shortcut is OK"); 324 return k2; 325 } else { 326 return ciObjArrayKlass::make(elem); 327 } 328 } else { 329 return object_klass; 330 } 331 } else { 332 // Must be two plain old instance klasses. 333 assert(k1->is_instance_klass(), "previous cases handle non-instances"); 334 assert(k2->is_instance_klass(), "previous cases handle non-instances"); 335 return k1->least_common_ancestor(k2); 336 } 337 } 338 } 339 340 341 // ------------------------------------------------------------------ 342 // ciTypeFlow::StateVector::StateVector 343 // 344 // Build a new state vector 345 ciTypeFlow::StateVector::StateVector(ciTypeFlow* analyzer) { 346 _outer = analyzer; 347 _stack_size = -1; 348 _monitor_count = -1; 349 // Allocate the _types array 350 int max_cells = analyzer->max_cells(); 351 _types = (ciType**)analyzer->arena()->Amalloc(sizeof(ciType*) * max_cells); 352 for (int i=0; i<max_cells; i++) { 353 _types[i] = top_type(); 354 } 355 _trap_bci = -1; 356 _trap_index = 0; 357 _def_locals.clear(); 358 } 359 360 361 // ------------------------------------------------------------------ 362 // ciTypeFlow::get_start_state 363 // 364 // Set this vector to the method entry state. 365 const ciTypeFlow::StateVector* ciTypeFlow::get_start_state() { 366 StateVector* state = new StateVector(this); 367 if (is_osr_flow()) { 368 ciTypeFlow* non_osr_flow = method()->get_flow_analysis(); 369 if (non_osr_flow->failing()) { 370 record_failure(non_osr_flow->failure_reason()); 371 return nullptr; 372 } 373 JsrSet* jsrs = new JsrSet(4); 374 Block* non_osr_block = non_osr_flow->existing_block_at(start_bci(), jsrs); 375 if (non_osr_block == nullptr) { 376 record_failure("cannot reach OSR point"); 377 return nullptr; 378 } 379 // load up the non-OSR state at this point 380 non_osr_block->copy_state_into(state); 381 int non_osr_start = non_osr_block->start(); 382 if (non_osr_start != start_bci()) { 383 // must flow forward from it 384 if (CITraceTypeFlow) { 385 tty->print_cr(">> Interpreting pre-OSR block %d:", non_osr_start); 386 } 387 Block* block = block_at(non_osr_start, jsrs); 388 assert(block->limit() == start_bci(), "must flow forward to start"); 389 flow_block(block, state, jsrs); 390 } 391 return state; 392 // Note: The code below would be an incorrect for an OSR flow, 393 // even if it were possible for an OSR entry point to be at bci zero. 394 } 395 // "Push" the method signature into the first few locals. 396 state->set_stack_size(-max_locals()); 397 if (!method()->is_static()) { 398 state->push(method()->holder()); 399 assert(state->tos() == state->local(0), ""); 400 } 401 for (ciSignatureStream str(method()->signature()); 402 !str.at_return_type(); 403 str.next()) { 404 state->push_translate(str.type()); 405 } 406 // Set the rest of the locals to bottom. 407 assert(state->stack_size() <= 0, "stack size should not be strictly positive"); 408 while (state->stack_size() < 0) { 409 state->push(state->bottom_type()); 410 } 411 // Lock an object, if necessary. 412 state->set_monitor_count(method()->is_synchronized() ? 1 : 0); 413 return state; 414 } 415 416 // ------------------------------------------------------------------ 417 // ciTypeFlow::StateVector::copy_into 418 // 419 // Copy our value into some other StateVector 420 void ciTypeFlow::StateVector::copy_into(ciTypeFlow::StateVector* copy) 421 const { 422 copy->set_stack_size(stack_size()); 423 copy->set_monitor_count(monitor_count()); 424 Cell limit = limit_cell(); 425 for (Cell c = start_cell(); c < limit; c = next_cell(c)) { 426 copy->set_type_at(c, type_at(c)); 427 } 428 } 429 430 // ------------------------------------------------------------------ 431 // ciTypeFlow::StateVector::meet 432 // 433 // Meets this StateVector with another, destructively modifying this 434 // one. Returns true if any modification takes place. 435 bool ciTypeFlow::StateVector::meet(const ciTypeFlow::StateVector* incoming) { 436 if (monitor_count() == -1) { 437 set_monitor_count(incoming->monitor_count()); 438 } 439 assert(monitor_count() == incoming->monitor_count(), "monitors must match"); 440 441 if (stack_size() == -1) { 442 set_stack_size(incoming->stack_size()); 443 Cell limit = limit_cell(); 444 #ifdef ASSERT 445 { for (Cell c = start_cell(); c < limit; c = next_cell(c)) { 446 assert(type_at(c) == top_type(), ""); 447 } } 448 #endif 449 // Make a simple copy of the incoming state. 450 for (Cell c = start_cell(); c < limit; c = next_cell(c)) { 451 set_type_at(c, incoming->type_at(c)); 452 } 453 return true; // it is always different the first time 454 } 455 #ifdef ASSERT 456 if (stack_size() != incoming->stack_size()) { 457 _outer->method()->print_codes(); 458 tty->print_cr("!!!! Stack size conflict"); 459 tty->print_cr("Current state:"); 460 print_on(tty); 461 tty->print_cr("Incoming state:"); 462 ((StateVector*)incoming)->print_on(tty); 463 } 464 #endif 465 assert(stack_size() == incoming->stack_size(), "sanity"); 466 467 bool different = false; 468 Cell limit = limit_cell(); 469 for (Cell c = start_cell(); c < limit; c = next_cell(c)) { 470 ciType* t1 = type_at(c); 471 ciType* t2 = incoming->type_at(c); 472 if (!t1->equals(t2)) { 473 ciType* new_type = type_meet(t1, t2); 474 if (!t1->equals(new_type)) { 475 set_type_at(c, new_type); 476 different = true; 477 } 478 } 479 } 480 return different; 481 } 482 483 // ------------------------------------------------------------------ 484 // ciTypeFlow::StateVector::meet_exception 485 // 486 // Meets this StateVector with another, destructively modifying this 487 // one. The incoming state is coming via an exception. Returns true 488 // if any modification takes place. 489 bool ciTypeFlow::StateVector::meet_exception(ciInstanceKlass* exc, 490 const ciTypeFlow::StateVector* incoming) { 491 if (monitor_count() == -1) { 492 set_monitor_count(incoming->monitor_count()); 493 } 494 assert(monitor_count() == incoming->monitor_count(), "monitors must match"); 495 496 if (stack_size() == -1) { 497 set_stack_size(1); 498 } 499 500 assert(stack_size() == 1, "must have one-element stack"); 501 502 bool different = false; 503 504 // Meet locals from incoming array. 505 Cell limit = local(_outer->max_locals()-1); 506 for (Cell c = start_cell(); c <= limit; c = next_cell(c)) { 507 ciType* t1 = type_at(c); 508 ciType* t2 = incoming->type_at(c); 509 if (!t1->equals(t2)) { 510 ciType* new_type = type_meet(t1, t2); 511 if (!t1->equals(new_type)) { 512 set_type_at(c, new_type); 513 different = true; 514 } 515 } 516 } 517 518 // Handle stack separately. When an exception occurs, the 519 // only stack entry is the exception instance. 520 ciType* tos_type = type_at_tos(); 521 if (!tos_type->equals(exc)) { 522 ciType* new_type = type_meet(tos_type, exc); 523 if (!tos_type->equals(new_type)) { 524 set_type_at_tos(new_type); 525 different = true; 526 } 527 } 528 529 return different; 530 } 531 532 // ------------------------------------------------------------------ 533 // ciTypeFlow::StateVector::push_translate 534 void ciTypeFlow::StateVector::push_translate(ciType* type) { 535 BasicType basic_type = type->basic_type(); 536 if (basic_type == T_BOOLEAN || basic_type == T_CHAR || 537 basic_type == T_BYTE || basic_type == T_SHORT) { 538 push_int(); 539 } else { 540 push(type); 541 if (type->is_two_word()) { 542 push(half_type(type)); 543 } 544 } 545 } 546 547 // ------------------------------------------------------------------ 548 // ciTypeFlow::StateVector::do_aaload 549 void ciTypeFlow::StateVector::do_aaload(ciBytecodeStream* str) { 550 pop_int(); 551 ciObjArrayKlass* array_klass = pop_objArray(); 552 if (array_klass == nullptr) { 553 // Did aaload on a null reference; push a null and ignore the exception. 554 // This instruction will never continue normally. All we have to do 555 // is report a value that will meet correctly with any downstream 556 // reference types on paths that will truly be executed. This null type 557 // meets with any reference type to yield that same reference type. 558 // (The compiler will generate an unconditional exception here.) 559 push(null_type()); 560 return; 561 } 562 if (!array_klass->is_loaded()) { 563 // Only fails for some -Xcomp runs 564 trap(str, array_klass, 565 Deoptimization::make_trap_request 566 (Deoptimization::Reason_unloaded, 567 Deoptimization::Action_reinterpret)); 568 return; 569 } 570 ciKlass* element_klass = array_klass->element_klass(); 571 if (!element_klass->is_loaded() && element_klass->is_instance_klass()) { 572 Untested("unloaded array element class in ciTypeFlow"); 573 trap(str, element_klass, 574 Deoptimization::make_trap_request 575 (Deoptimization::Reason_unloaded, 576 Deoptimization::Action_reinterpret)); 577 } else { 578 push_object(element_klass); 579 } 580 } 581 582 583 // ------------------------------------------------------------------ 584 // ciTypeFlow::StateVector::do_checkcast 585 void ciTypeFlow::StateVector::do_checkcast(ciBytecodeStream* str) { 586 bool will_link; 587 ciKlass* klass = str->get_klass(will_link); 588 if (!will_link) { 589 // VM's interpreter will not load 'klass' if object is null. 590 // Type flow after this block may still be needed in two situations: 591 // 1) C2 uses do_null_assert() and continues compilation for later blocks 592 // 2) C2 does an OSR compile in a later block (see bug 4778368). 593 pop_object(); 594 do_null_assert(klass); 595 } else { 596 pop_object(); 597 push_object(klass); 598 } 599 } 600 601 // ------------------------------------------------------------------ 602 // ciTypeFlow::StateVector::do_getfield 603 void ciTypeFlow::StateVector::do_getfield(ciBytecodeStream* str) { 604 // could add assert here for type of object. 605 pop_object(); 606 do_getstatic(str); 607 } 608 609 // ------------------------------------------------------------------ 610 // ciTypeFlow::StateVector::do_getstatic 611 void ciTypeFlow::StateVector::do_getstatic(ciBytecodeStream* str) { 612 bool will_link; 613 ciField* field = str->get_field(will_link); 614 if (!will_link) { 615 trap(str, field->holder(), str->get_field_holder_index()); 616 } else { 617 ciType* field_type = field->type(); 618 if (!field_type->is_loaded()) { 619 // Normally, we need the field's type to be loaded if we are to 620 // do anything interesting with its value. 621 // We used to do this: trap(str, str->get_field_signature_index()); 622 // 623 // There is one good reason not to trap here. Execution can 624 // get past this "getfield" or "getstatic" if the value of 625 // the field is null. As long as the value is null, the class 626 // does not need to be loaded! The compiler must assume that 627 // the value of the unloaded class reference is null; if the code 628 // ever sees a non-null value, loading has occurred. 629 // 630 // This actually happens often enough to be annoying. If the 631 // compiler throws an uncommon trap at this bytecode, you can 632 // get an endless loop of recompilations, when all the code 633 // needs to do is load a series of null values. Also, a trap 634 // here can make an OSR entry point unreachable, triggering the 635 // assert on non_osr_block in ciTypeFlow::get_start_state. 636 // (See bug 4379915.) 637 do_null_assert(field_type->as_klass()); 638 } else { 639 push_translate(field_type); 640 } 641 } 642 } 643 644 // ------------------------------------------------------------------ 645 // ciTypeFlow::StateVector::do_invoke 646 void ciTypeFlow::StateVector::do_invoke(ciBytecodeStream* str, 647 bool has_receiver) { 648 bool will_link; 649 ciSignature* declared_signature = nullptr; 650 ciMethod* callee = str->get_method(will_link, &declared_signature); 651 assert(declared_signature != nullptr, "cannot be null"); 652 if (!will_link) { 653 // We weren't able to find the method. 654 if (str->cur_bc() == Bytecodes::_invokedynamic) { 655 trap(str, nullptr, 656 Deoptimization::make_trap_request 657 (Deoptimization::Reason_uninitialized, 658 Deoptimization::Action_reinterpret)); 659 } else { 660 ciKlass* unloaded_holder = callee->holder(); 661 trap(str, unloaded_holder, str->get_method_holder_index()); 662 } 663 } else { 664 // We are using the declared signature here because it might be 665 // different from the callee signature (Cf. invokedynamic and 666 // invokehandle). 667 ciSignatureStream sigstr(declared_signature); 668 const int arg_size = declared_signature->size(); 669 const int stack_base = stack_size() - arg_size; 670 int i = 0; 671 for( ; !sigstr.at_return_type(); sigstr.next()) { 672 ciType* type = sigstr.type(); 673 ciType* stack_type = type_at(stack(stack_base + i++)); 674 // Do I want to check this type? 675 // assert(stack_type->is_subtype_of(type), "bad type for field value"); 676 if (type->is_two_word()) { 677 ciType* stack_type2 = type_at(stack(stack_base + i++)); 678 assert(stack_type2->equals(half_type(type)), "must be 2nd half"); 679 } 680 } 681 assert(arg_size == i, "must match"); 682 for (int j = 0; j < arg_size; j++) { 683 pop(); 684 } 685 if (has_receiver) { 686 // Check this? 687 pop_object(); 688 } 689 assert(!sigstr.is_done(), "must have return type"); 690 ciType* return_type = sigstr.type(); 691 if (!return_type->is_void()) { 692 if (!return_type->is_loaded()) { 693 // As in do_getstatic(), generally speaking, we need the return type to 694 // be loaded if we are to do anything interesting with its value. 695 // We used to do this: trap(str, str->get_method_signature_index()); 696 // 697 // We do not trap here since execution can get past this invoke if 698 // the return value is null. As long as the value is null, the class 699 // does not need to be loaded! The compiler must assume that 700 // the value of the unloaded class reference is null; if the code 701 // ever sees a non-null value, loading has occurred. 702 // 703 // See do_getstatic() for similar explanation, as well as bug 4684993. 704 do_null_assert(return_type->as_klass()); 705 } else { 706 push_translate(return_type); 707 } 708 } 709 } 710 } 711 712 // ------------------------------------------------------------------ 713 // ciTypeFlow::StateVector::do_jsr 714 void ciTypeFlow::StateVector::do_jsr(ciBytecodeStream* str) { 715 push(ciReturnAddress::make(str->next_bci())); 716 } 717 718 // ------------------------------------------------------------------ 719 // ciTypeFlow::StateVector::do_ldc 720 void ciTypeFlow::StateVector::do_ldc(ciBytecodeStream* str) { 721 if (str->is_in_error()) { 722 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unhandled, 723 Deoptimization::Action_none)); 724 return; 725 } 726 ciConstant con = str->get_constant(); 727 if (con.is_valid()) { 728 int cp_index = str->get_constant_pool_index(); 729 if (!con.is_loaded()) { 730 trap(str, nullptr, Deoptimization::make_trap_request(Deoptimization::Reason_unloaded, 731 Deoptimization::Action_reinterpret, 732 cp_index)); 733 return; 734 } 735 BasicType basic_type = str->get_basic_type_for_constant_at(cp_index); 736 if (is_reference_type(basic_type)) { 737 ciObject* obj = con.as_object(); 738 if (obj->is_null_object()) { 739 push_null(); 740 } else { 741 assert(obj->is_instance() || obj->is_array(), "must be java_mirror of klass"); 742 push_object(obj->klass()); 743 } 744 } else { 745 assert(basic_type == con.basic_type() || con.basic_type() == T_OBJECT, 746 "not a boxed form: %s vs %s", type2name(basic_type), type2name(con.basic_type())); 747 push_translate(ciType::make(basic_type)); 748 } 749 } else { 750 // OutOfMemoryError in the CI while loading a String constant. 751 push_null(); 752 outer()->record_failure("ldc did not link"); 753 } 754 } 755 756 // ------------------------------------------------------------------ 757 // ciTypeFlow::StateVector::do_multianewarray 758 void ciTypeFlow::StateVector::do_multianewarray(ciBytecodeStream* str) { 759 int dimensions = str->get_dimensions(); 760 bool will_link; 761 ciArrayKlass* array_klass = str->get_klass(will_link)->as_array_klass(); 762 if (!will_link) { 763 trap(str, array_klass, str->get_klass_index()); 764 } else { 765 for (int i = 0; i < dimensions; i++) { 766 pop_int(); 767 } 768 push_object(array_klass); 769 } 770 } 771 772 // ------------------------------------------------------------------ 773 // ciTypeFlow::StateVector::do_new 774 void ciTypeFlow::StateVector::do_new(ciBytecodeStream* str) { 775 bool will_link; 776 ciKlass* klass = str->get_klass(will_link); 777 if (!will_link || str->is_unresolved_klass()) { 778 trap(str, klass, str->get_klass_index()); 779 } else { 780 push_object(klass); 781 } 782 } 783 784 // ------------------------------------------------------------------ 785 // ciTypeFlow::StateVector::do_newarray 786 void ciTypeFlow::StateVector::do_newarray(ciBytecodeStream* str) { 787 pop_int(); 788 ciKlass* klass = ciTypeArrayKlass::make((BasicType)str->get_index()); 789 push_object(klass); 790 } 791 792 // ------------------------------------------------------------------ 793 // ciTypeFlow::StateVector::do_putfield 794 void ciTypeFlow::StateVector::do_putfield(ciBytecodeStream* str) { 795 do_putstatic(str); 796 if (_trap_bci != -1) return; // unloaded field holder, etc. 797 // could add assert here for type of object. 798 pop_object(); 799 } 800 801 // ------------------------------------------------------------------ 802 // ciTypeFlow::StateVector::do_putstatic 803 void ciTypeFlow::StateVector::do_putstatic(ciBytecodeStream* str) { 804 bool will_link; 805 ciField* field = str->get_field(will_link); 806 if (!will_link) { 807 trap(str, field->holder(), str->get_field_holder_index()); 808 } else { 809 ciType* field_type = field->type(); 810 ciType* type = pop_value(); 811 // Do I want to check this type? 812 // assert(type->is_subtype_of(field_type), "bad type for field value"); 813 if (field_type->is_two_word()) { 814 ciType* type2 = pop_value(); 815 assert(type2->is_two_word(), "must be 2nd half"); 816 assert(type == half_type(type2), "must be 2nd half"); 817 } 818 } 819 } 820 821 // ------------------------------------------------------------------ 822 // ciTypeFlow::StateVector::do_ret 823 void ciTypeFlow::StateVector::do_ret(ciBytecodeStream* str) { 824 Cell index = local(str->get_index()); 825 826 ciType* address = type_at(index); 827 assert(address->is_return_address(), "bad return address"); 828 set_type_at(index, bottom_type()); 829 } 830 831 // ------------------------------------------------------------------ 832 // ciTypeFlow::StateVector::trap 833 // 834 // Stop interpretation of this path with a trap. 835 void ciTypeFlow::StateVector::trap(ciBytecodeStream* str, ciKlass* klass, int index) { 836 _trap_bci = str->cur_bci(); 837 _trap_index = index; 838 839 // Log information about this trap: 840 CompileLog* log = outer()->env()->log(); 841 if (log != nullptr) { 842 int mid = log->identify(outer()->method()); 843 int kid = (klass == nullptr)? -1: log->identify(klass); 844 log->begin_elem("uncommon_trap method='%d' bci='%d'", mid, str->cur_bci()); 845 char buf[100]; 846 log->print(" %s", Deoptimization::format_trap_request(buf, sizeof(buf), 847 index)); 848 if (kid >= 0) 849 log->print(" klass='%d'", kid); 850 log->end_elem(); 851 } 852 } 853 854 // ------------------------------------------------------------------ 855 // ciTypeFlow::StateVector::do_null_assert 856 // Corresponds to graphKit::do_null_assert. 857 void ciTypeFlow::StateVector::do_null_assert(ciKlass* unloaded_klass) { 858 if (unloaded_klass->is_loaded()) { 859 // We failed to link, but we can still compute with this class, 860 // since it is loaded somewhere. The compiler will uncommon_trap 861 // if the object is not null, but the typeflow pass can not assume 862 // that the object will be null, otherwise it may incorrectly tell 863 // the parser that an object is known to be null. 4761344, 4807707 864 push_object(unloaded_klass); 865 } else { 866 // The class is not loaded anywhere. It is safe to model the 867 // null in the typestates, because we can compile in a null check 868 // which will deoptimize us if someone manages to load the 869 // class later. 870 push_null(); 871 } 872 } 873 874 875 // ------------------------------------------------------------------ 876 // ciTypeFlow::StateVector::apply_one_bytecode 877 // 878 // Apply the effect of one bytecode to this StateVector 879 bool ciTypeFlow::StateVector::apply_one_bytecode(ciBytecodeStream* str) { 880 _trap_bci = -1; 881 _trap_index = 0; 882 883 if (CITraceTypeFlow) { 884 tty->print_cr(">> Interpreting bytecode %d:%s", str->cur_bci(), 885 Bytecodes::name(str->cur_bc())); 886 } 887 888 switch(str->cur_bc()) { 889 case Bytecodes::_aaload: do_aaload(str); break; 890 891 case Bytecodes::_aastore: 892 { 893 pop_object(); 894 pop_int(); 895 pop_objArray(); 896 break; 897 } 898 case Bytecodes::_aconst_null: 899 { 900 push_null(); 901 break; 902 } 903 case Bytecodes::_aload: load_local_object(str->get_index()); break; 904 case Bytecodes::_aload_0: load_local_object(0); break; 905 case Bytecodes::_aload_1: load_local_object(1); break; 906 case Bytecodes::_aload_2: load_local_object(2); break; 907 case Bytecodes::_aload_3: load_local_object(3); break; 908 909 case Bytecodes::_anewarray: 910 { 911 pop_int(); 912 bool will_link; 913 ciKlass* element_klass = str->get_klass(will_link); 914 if (!will_link) { 915 trap(str, element_klass, str->get_klass_index()); 916 } else { 917 push_object(ciObjArrayKlass::make(element_klass)); 918 } 919 break; 920 } 921 case Bytecodes::_areturn: 922 case Bytecodes::_ifnonnull: 923 case Bytecodes::_ifnull: 924 { 925 pop_object(); 926 break; 927 } 928 case Bytecodes::_monitorenter: 929 { 930 pop_object(); 931 set_monitor_count(monitor_count() + 1); 932 break; 933 } 934 case Bytecodes::_monitorexit: 935 { 936 pop_object(); 937 assert(monitor_count() > 0, "must be a monitor to exit from"); 938 set_monitor_count(monitor_count() - 1); 939 break; 940 } 941 case Bytecodes::_arraylength: 942 { 943 pop_array(); 944 push_int(); 945 break; 946 } 947 case Bytecodes::_astore: store_local_object(str->get_index()); break; 948 case Bytecodes::_astore_0: store_local_object(0); break; 949 case Bytecodes::_astore_1: store_local_object(1); break; 950 case Bytecodes::_astore_2: store_local_object(2); break; 951 case Bytecodes::_astore_3: store_local_object(3); break; 952 953 case Bytecodes::_athrow: 954 { 955 NEEDS_CLEANUP; 956 pop_object(); 957 break; 958 } 959 case Bytecodes::_baload: 960 case Bytecodes::_caload: 961 case Bytecodes::_iaload: 962 case Bytecodes::_saload: 963 { 964 pop_int(); 965 ciTypeArrayKlass* array_klass = pop_typeArray(); 966 // Put assert here for right type? 967 push_int(); 968 break; 969 } 970 case Bytecodes::_bastore: 971 case Bytecodes::_castore: 972 case Bytecodes::_iastore: 973 case Bytecodes::_sastore: 974 { 975 pop_int(); 976 pop_int(); 977 pop_typeArray(); 978 // assert here? 979 break; 980 } 981 case Bytecodes::_bipush: 982 case Bytecodes::_iconst_m1: 983 case Bytecodes::_iconst_0: 984 case Bytecodes::_iconst_1: 985 case Bytecodes::_iconst_2: 986 case Bytecodes::_iconst_3: 987 case Bytecodes::_iconst_4: 988 case Bytecodes::_iconst_5: 989 case Bytecodes::_sipush: 990 { 991 push_int(); 992 break; 993 } 994 case Bytecodes::_checkcast: do_checkcast(str); break; 995 996 case Bytecodes::_d2f: 997 { 998 pop_double(); 999 push_float(); 1000 break; 1001 } 1002 case Bytecodes::_d2i: 1003 { 1004 pop_double(); 1005 push_int(); 1006 break; 1007 } 1008 case Bytecodes::_d2l: 1009 { 1010 pop_double(); 1011 push_long(); 1012 break; 1013 } 1014 case Bytecodes::_dadd: 1015 case Bytecodes::_ddiv: 1016 case Bytecodes::_dmul: 1017 case Bytecodes::_drem: 1018 case Bytecodes::_dsub: 1019 { 1020 pop_double(); 1021 pop_double(); 1022 push_double(); 1023 break; 1024 } 1025 case Bytecodes::_daload: 1026 { 1027 pop_int(); 1028 ciTypeArrayKlass* array_klass = pop_typeArray(); 1029 // Put assert here for right type? 1030 push_double(); 1031 break; 1032 } 1033 case Bytecodes::_dastore: 1034 { 1035 pop_double(); 1036 pop_int(); 1037 pop_typeArray(); 1038 // assert here? 1039 break; 1040 } 1041 case Bytecodes::_dcmpg: 1042 case Bytecodes::_dcmpl: 1043 { 1044 pop_double(); 1045 pop_double(); 1046 push_int(); 1047 break; 1048 } 1049 case Bytecodes::_dconst_0: 1050 case Bytecodes::_dconst_1: 1051 { 1052 push_double(); 1053 break; 1054 } 1055 case Bytecodes::_dload: load_local_double(str->get_index()); break; 1056 case Bytecodes::_dload_0: load_local_double(0); break; 1057 case Bytecodes::_dload_1: load_local_double(1); break; 1058 case Bytecodes::_dload_2: load_local_double(2); break; 1059 case Bytecodes::_dload_3: load_local_double(3); break; 1060 1061 case Bytecodes::_dneg: 1062 { 1063 pop_double(); 1064 push_double(); 1065 break; 1066 } 1067 case Bytecodes::_dreturn: 1068 { 1069 pop_double(); 1070 break; 1071 } 1072 case Bytecodes::_dstore: store_local_double(str->get_index()); break; 1073 case Bytecodes::_dstore_0: store_local_double(0); break; 1074 case Bytecodes::_dstore_1: store_local_double(1); break; 1075 case Bytecodes::_dstore_2: store_local_double(2); break; 1076 case Bytecodes::_dstore_3: store_local_double(3); break; 1077 1078 case Bytecodes::_dup: 1079 { 1080 push(type_at_tos()); 1081 break; 1082 } 1083 case Bytecodes::_dup_x1: 1084 { 1085 ciType* value1 = pop_value(); 1086 ciType* value2 = pop_value(); 1087 push(value1); 1088 push(value2); 1089 push(value1); 1090 break; 1091 } 1092 case Bytecodes::_dup_x2: 1093 { 1094 ciType* value1 = pop_value(); 1095 ciType* value2 = pop_value(); 1096 ciType* value3 = pop_value(); 1097 push(value1); 1098 push(value3); 1099 push(value2); 1100 push(value1); 1101 break; 1102 } 1103 case Bytecodes::_dup2: 1104 { 1105 ciType* value1 = pop_value(); 1106 ciType* value2 = pop_value(); 1107 push(value2); 1108 push(value1); 1109 push(value2); 1110 push(value1); 1111 break; 1112 } 1113 case Bytecodes::_dup2_x1: 1114 { 1115 ciType* value1 = pop_value(); 1116 ciType* value2 = pop_value(); 1117 ciType* value3 = pop_value(); 1118 push(value2); 1119 push(value1); 1120 push(value3); 1121 push(value2); 1122 push(value1); 1123 break; 1124 } 1125 case Bytecodes::_dup2_x2: 1126 { 1127 ciType* value1 = pop_value(); 1128 ciType* value2 = pop_value(); 1129 ciType* value3 = pop_value(); 1130 ciType* value4 = pop_value(); 1131 push(value2); 1132 push(value1); 1133 push(value4); 1134 push(value3); 1135 push(value2); 1136 push(value1); 1137 break; 1138 } 1139 case Bytecodes::_f2d: 1140 { 1141 pop_float(); 1142 push_double(); 1143 break; 1144 } 1145 case Bytecodes::_f2i: 1146 { 1147 pop_float(); 1148 push_int(); 1149 break; 1150 } 1151 case Bytecodes::_f2l: 1152 { 1153 pop_float(); 1154 push_long(); 1155 break; 1156 } 1157 case Bytecodes::_fadd: 1158 case Bytecodes::_fdiv: 1159 case Bytecodes::_fmul: 1160 case Bytecodes::_frem: 1161 case Bytecodes::_fsub: 1162 { 1163 pop_float(); 1164 pop_float(); 1165 push_float(); 1166 break; 1167 } 1168 case Bytecodes::_faload: 1169 { 1170 pop_int(); 1171 ciTypeArrayKlass* array_klass = pop_typeArray(); 1172 // Put assert here. 1173 push_float(); 1174 break; 1175 } 1176 case Bytecodes::_fastore: 1177 { 1178 pop_float(); 1179 pop_int(); 1180 ciTypeArrayKlass* array_klass = pop_typeArray(); 1181 // Put assert here. 1182 break; 1183 } 1184 case Bytecodes::_fcmpg: 1185 case Bytecodes::_fcmpl: 1186 { 1187 pop_float(); 1188 pop_float(); 1189 push_int(); 1190 break; 1191 } 1192 case Bytecodes::_fconst_0: 1193 case Bytecodes::_fconst_1: 1194 case Bytecodes::_fconst_2: 1195 { 1196 push_float(); 1197 break; 1198 } 1199 case Bytecodes::_fload: load_local_float(str->get_index()); break; 1200 case Bytecodes::_fload_0: load_local_float(0); break; 1201 case Bytecodes::_fload_1: load_local_float(1); break; 1202 case Bytecodes::_fload_2: load_local_float(2); break; 1203 case Bytecodes::_fload_3: load_local_float(3); break; 1204 1205 case Bytecodes::_fneg: 1206 { 1207 pop_float(); 1208 push_float(); 1209 break; 1210 } 1211 case Bytecodes::_freturn: 1212 { 1213 pop_float(); 1214 break; 1215 } 1216 case Bytecodes::_fstore: store_local_float(str->get_index()); break; 1217 case Bytecodes::_fstore_0: store_local_float(0); break; 1218 case Bytecodes::_fstore_1: store_local_float(1); break; 1219 case Bytecodes::_fstore_2: store_local_float(2); break; 1220 case Bytecodes::_fstore_3: store_local_float(3); break; 1221 1222 case Bytecodes::_getfield: do_getfield(str); break; 1223 case Bytecodes::_getstatic: do_getstatic(str); break; 1224 1225 case Bytecodes::_goto: 1226 case Bytecodes::_goto_w: 1227 case Bytecodes::_nop: 1228 case Bytecodes::_return: 1229 { 1230 // do nothing. 1231 break; 1232 } 1233 case Bytecodes::_i2b: 1234 case Bytecodes::_i2c: 1235 case Bytecodes::_i2s: 1236 case Bytecodes::_ineg: 1237 { 1238 pop_int(); 1239 push_int(); 1240 break; 1241 } 1242 case Bytecodes::_i2d: 1243 { 1244 pop_int(); 1245 push_double(); 1246 break; 1247 } 1248 case Bytecodes::_i2f: 1249 { 1250 pop_int(); 1251 push_float(); 1252 break; 1253 } 1254 case Bytecodes::_i2l: 1255 { 1256 pop_int(); 1257 push_long(); 1258 break; 1259 } 1260 case Bytecodes::_iadd: 1261 case Bytecodes::_iand: 1262 case Bytecodes::_idiv: 1263 case Bytecodes::_imul: 1264 case Bytecodes::_ior: 1265 case Bytecodes::_irem: 1266 case Bytecodes::_ishl: 1267 case Bytecodes::_ishr: 1268 case Bytecodes::_isub: 1269 case Bytecodes::_iushr: 1270 case Bytecodes::_ixor: 1271 { 1272 pop_int(); 1273 pop_int(); 1274 push_int(); 1275 break; 1276 } 1277 case Bytecodes::_if_acmpeq: 1278 case Bytecodes::_if_acmpne: 1279 { 1280 pop_object(); 1281 pop_object(); 1282 break; 1283 } 1284 case Bytecodes::_if_icmpeq: 1285 case Bytecodes::_if_icmpge: 1286 case Bytecodes::_if_icmpgt: 1287 case Bytecodes::_if_icmple: 1288 case Bytecodes::_if_icmplt: 1289 case Bytecodes::_if_icmpne: 1290 { 1291 pop_int(); 1292 pop_int(); 1293 break; 1294 } 1295 case Bytecodes::_ifeq: 1296 case Bytecodes::_ifle: 1297 case Bytecodes::_iflt: 1298 case Bytecodes::_ifge: 1299 case Bytecodes::_ifgt: 1300 case Bytecodes::_ifne: 1301 case Bytecodes::_ireturn: 1302 case Bytecodes::_lookupswitch: 1303 case Bytecodes::_tableswitch: 1304 { 1305 pop_int(); 1306 break; 1307 } 1308 case Bytecodes::_iinc: 1309 { 1310 int lnum = str->get_index(); 1311 check_int(local(lnum)); 1312 store_to_local(lnum); 1313 break; 1314 } 1315 case Bytecodes::_iload: load_local_int(str->get_index()); break; 1316 case Bytecodes::_iload_0: load_local_int(0); break; 1317 case Bytecodes::_iload_1: load_local_int(1); break; 1318 case Bytecodes::_iload_2: load_local_int(2); break; 1319 case Bytecodes::_iload_3: load_local_int(3); break; 1320 1321 case Bytecodes::_instanceof: 1322 { 1323 // Check for uncommon trap: 1324 do_checkcast(str); 1325 pop_object(); 1326 push_int(); 1327 break; 1328 } 1329 case Bytecodes::_invokeinterface: do_invoke(str, true); break; 1330 case Bytecodes::_invokespecial: do_invoke(str, true); break; 1331 case Bytecodes::_invokestatic: do_invoke(str, false); break; 1332 case Bytecodes::_invokevirtual: do_invoke(str, true); break; 1333 case Bytecodes::_invokedynamic: do_invoke(str, false); break; 1334 1335 case Bytecodes::_istore: store_local_int(str->get_index()); break; 1336 case Bytecodes::_istore_0: store_local_int(0); break; 1337 case Bytecodes::_istore_1: store_local_int(1); break; 1338 case Bytecodes::_istore_2: store_local_int(2); break; 1339 case Bytecodes::_istore_3: store_local_int(3); break; 1340 1341 case Bytecodes::_jsr: 1342 case Bytecodes::_jsr_w: do_jsr(str); break; 1343 1344 case Bytecodes::_l2d: 1345 { 1346 pop_long(); 1347 push_double(); 1348 break; 1349 } 1350 case Bytecodes::_l2f: 1351 { 1352 pop_long(); 1353 push_float(); 1354 break; 1355 } 1356 case Bytecodes::_l2i: 1357 { 1358 pop_long(); 1359 push_int(); 1360 break; 1361 } 1362 case Bytecodes::_ladd: 1363 case Bytecodes::_land: 1364 case Bytecodes::_ldiv: 1365 case Bytecodes::_lmul: 1366 case Bytecodes::_lor: 1367 case Bytecodes::_lrem: 1368 case Bytecodes::_lsub: 1369 case Bytecodes::_lxor: 1370 { 1371 pop_long(); 1372 pop_long(); 1373 push_long(); 1374 break; 1375 } 1376 case Bytecodes::_laload: 1377 { 1378 pop_int(); 1379 ciTypeArrayKlass* array_klass = pop_typeArray(); 1380 // Put assert here for right type? 1381 push_long(); 1382 break; 1383 } 1384 case Bytecodes::_lastore: 1385 { 1386 pop_long(); 1387 pop_int(); 1388 pop_typeArray(); 1389 // assert here? 1390 break; 1391 } 1392 case Bytecodes::_lcmp: 1393 { 1394 pop_long(); 1395 pop_long(); 1396 push_int(); 1397 break; 1398 } 1399 case Bytecodes::_lconst_0: 1400 case Bytecodes::_lconst_1: 1401 { 1402 push_long(); 1403 break; 1404 } 1405 case Bytecodes::_ldc: 1406 case Bytecodes::_ldc_w: 1407 case Bytecodes::_ldc2_w: 1408 { 1409 do_ldc(str); 1410 break; 1411 } 1412 1413 case Bytecodes::_lload: load_local_long(str->get_index()); break; 1414 case Bytecodes::_lload_0: load_local_long(0); break; 1415 case Bytecodes::_lload_1: load_local_long(1); break; 1416 case Bytecodes::_lload_2: load_local_long(2); break; 1417 case Bytecodes::_lload_3: load_local_long(3); break; 1418 1419 case Bytecodes::_lneg: 1420 { 1421 pop_long(); 1422 push_long(); 1423 break; 1424 } 1425 case Bytecodes::_lreturn: 1426 { 1427 pop_long(); 1428 break; 1429 } 1430 case Bytecodes::_lshl: 1431 case Bytecodes::_lshr: 1432 case Bytecodes::_lushr: 1433 { 1434 pop_int(); 1435 pop_long(); 1436 push_long(); 1437 break; 1438 } 1439 case Bytecodes::_lstore: store_local_long(str->get_index()); break; 1440 case Bytecodes::_lstore_0: store_local_long(0); break; 1441 case Bytecodes::_lstore_1: store_local_long(1); break; 1442 case Bytecodes::_lstore_2: store_local_long(2); break; 1443 case Bytecodes::_lstore_3: store_local_long(3); break; 1444 1445 case Bytecodes::_multianewarray: do_multianewarray(str); break; 1446 1447 case Bytecodes::_new: do_new(str); break; 1448 1449 case Bytecodes::_newarray: do_newarray(str); break; 1450 1451 case Bytecodes::_pop: 1452 { 1453 pop(); 1454 break; 1455 } 1456 case Bytecodes::_pop2: 1457 { 1458 pop(); 1459 pop(); 1460 break; 1461 } 1462 1463 case Bytecodes::_putfield: do_putfield(str); break; 1464 case Bytecodes::_putstatic: do_putstatic(str); break; 1465 1466 case Bytecodes::_ret: do_ret(str); break; 1467 1468 case Bytecodes::_swap: 1469 { 1470 ciType* value1 = pop_value(); 1471 ciType* value2 = pop_value(); 1472 push(value1); 1473 push(value2); 1474 break; 1475 } 1476 case Bytecodes::_wide: 1477 default: 1478 { 1479 // The iterator should skip this. 1480 ShouldNotReachHere(); 1481 break; 1482 } 1483 } 1484 1485 if (CITraceTypeFlow) { 1486 print_on(tty); 1487 } 1488 1489 return (_trap_bci != -1); 1490 } 1491 1492 #ifndef PRODUCT 1493 // ------------------------------------------------------------------ 1494 // ciTypeFlow::StateVector::print_cell_on 1495 void ciTypeFlow::StateVector::print_cell_on(outputStream* st, Cell c) const { 1496 ciType* type = type_at(c); 1497 if (type == top_type()) { 1498 st->print("top"); 1499 } else if (type == bottom_type()) { 1500 st->print("bottom"); 1501 } else if (type == null_type()) { 1502 st->print("null"); 1503 } else if (type == long2_type()) { 1504 st->print("long2"); 1505 } else if (type == double2_type()) { 1506 st->print("double2"); 1507 } else if (is_int(type)) { 1508 st->print("int"); 1509 } else if (is_long(type)) { 1510 st->print("long"); 1511 } else if (is_float(type)) { 1512 st->print("float"); 1513 } else if (is_double(type)) { 1514 st->print("double"); 1515 } else if (type->is_return_address()) { 1516 st->print("address(%d)", type->as_return_address()->bci()); 1517 } else { 1518 if (type->is_klass()) { 1519 type->as_klass()->name()->print_symbol_on(st); 1520 } else { 1521 st->print("UNEXPECTED TYPE"); 1522 type->print(); 1523 } 1524 } 1525 } 1526 1527 // ------------------------------------------------------------------ 1528 // ciTypeFlow::StateVector::print_on 1529 void ciTypeFlow::StateVector::print_on(outputStream* st) const { 1530 int num_locals = _outer->max_locals(); 1531 int num_stack = stack_size(); 1532 int num_monitors = monitor_count(); 1533 st->print_cr(" State : locals %d, stack %d, monitors %d", num_locals, num_stack, num_monitors); 1534 if (num_stack >= 0) { 1535 int i; 1536 for (i = 0; i < num_locals; i++) { 1537 st->print(" local %2d : ", i); 1538 print_cell_on(st, local(i)); 1539 st->cr(); 1540 } 1541 for (i = 0; i < num_stack; i++) { 1542 st->print(" stack %2d : ", i); 1543 print_cell_on(st, stack(i)); 1544 st->cr(); 1545 } 1546 } 1547 } 1548 #endif 1549 1550 1551 // ------------------------------------------------------------------ 1552 // ciTypeFlow::SuccIter::next 1553 // 1554 void ciTypeFlow::SuccIter::next() { 1555 int succ_ct = _pred->successors()->length(); 1556 int next = _index + 1; 1557 if (next < succ_ct) { 1558 _index = next; 1559 _succ = _pred->successors()->at(next); 1560 return; 1561 } 1562 for (int i = next - succ_ct; i < _pred->exceptions()->length(); i++) { 1563 // Do not compile any code for unloaded exception types. 1564 // Following compiler passes are responsible for doing this also. 1565 ciInstanceKlass* exception_klass = _pred->exc_klasses()->at(i); 1566 if (exception_klass->is_loaded()) { 1567 _index = next; 1568 _succ = _pred->exceptions()->at(i); 1569 return; 1570 } 1571 next++; 1572 } 1573 _index = -1; 1574 _succ = nullptr; 1575 } 1576 1577 // ------------------------------------------------------------------ 1578 // ciTypeFlow::SuccIter::set_succ 1579 // 1580 void ciTypeFlow::SuccIter::set_succ(Block* succ) { 1581 int succ_ct = _pred->successors()->length(); 1582 if (_index < succ_ct) { 1583 _pred->successors()->at_put(_index, succ); 1584 } else { 1585 int idx = _index - succ_ct; 1586 _pred->exceptions()->at_put(idx, succ); 1587 } 1588 } 1589 1590 // ciTypeFlow::Block 1591 // 1592 // A basic block. 1593 1594 // ------------------------------------------------------------------ 1595 // ciTypeFlow::Block::Block 1596 ciTypeFlow::Block::Block(ciTypeFlow* outer, 1597 ciBlock *ciblk, 1598 ciTypeFlow::JsrSet* jsrs) : _predecessors(outer->arena(), 1, 0, nullptr) { 1599 _ciblock = ciblk; 1600 _exceptions = nullptr; 1601 _exc_klasses = nullptr; 1602 _successors = nullptr; 1603 _state = new (outer->arena()) StateVector(outer); 1604 JsrSet* new_jsrs = 1605 new (outer->arena()) JsrSet(outer->arena(), jsrs->size()); 1606 jsrs->copy_into(new_jsrs); 1607 _jsrs = new_jsrs; 1608 _next = nullptr; 1609 _on_work_list = false; 1610 _backedge_copy = false; 1611 _has_monitorenter = false; 1612 _trap_bci = -1; 1613 _trap_index = 0; 1614 df_init(); 1615 1616 if (CITraceTypeFlow) { 1617 tty->print_cr(">> Created new block"); 1618 print_on(tty); 1619 } 1620 1621 assert(this->outer() == outer, "outer link set up"); 1622 assert(!outer->have_block_count(), "must not have mapped blocks yet"); 1623 } 1624 1625 // ------------------------------------------------------------------ 1626 // ciTypeFlow::Block::df_init 1627 void ciTypeFlow::Block::df_init() { 1628 _pre_order = -1; assert(!has_pre_order(), ""); 1629 _post_order = -1; assert(!has_post_order(), ""); 1630 _loop = nullptr; 1631 _irreducible_loop_head = false; 1632 _irreducible_loop_secondary_entry = false; 1633 _rpo_next = nullptr; 1634 } 1635 1636 // ------------------------------------------------------------------ 1637 // ciTypeFlow::Block::successors 1638 // 1639 // Get the successors for this Block. 1640 GrowableArray<ciTypeFlow::Block*>* 1641 ciTypeFlow::Block::successors(ciBytecodeStream* str, 1642 ciTypeFlow::StateVector* state, 1643 ciTypeFlow::JsrSet* jsrs) { 1644 if (_successors == nullptr) { 1645 if (CITraceTypeFlow) { 1646 tty->print(">> Computing successors for block "); 1647 print_value_on(tty); 1648 tty->cr(); 1649 } 1650 1651 ciTypeFlow* analyzer = outer(); 1652 Arena* arena = analyzer->arena(); 1653 Block* block = nullptr; 1654 bool has_successor = !has_trap() && 1655 (control() != ciBlock::fall_through_bci || limit() < analyzer->code_size()); 1656 if (!has_successor) { 1657 _successors = 1658 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1659 // No successors 1660 } else if (control() == ciBlock::fall_through_bci) { 1661 assert(str->cur_bci() == limit(), "bad block end"); 1662 // This block simply falls through to the next. 1663 _successors = 1664 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1665 1666 Block* block = analyzer->block_at(limit(), _jsrs); 1667 assert(_successors->length() == FALL_THROUGH, ""); 1668 _successors->append(block); 1669 } else { 1670 int current_bci = str->cur_bci(); 1671 int next_bci = str->next_bci(); 1672 int branch_bci = -1; 1673 Block* target = nullptr; 1674 assert(str->next_bci() == limit(), "bad block end"); 1675 // This block is not a simple fall-though. Interpret 1676 // the current bytecode to find our successors. 1677 switch (str->cur_bc()) { 1678 case Bytecodes::_ifeq: case Bytecodes::_ifne: 1679 case Bytecodes::_iflt: case Bytecodes::_ifge: 1680 case Bytecodes::_ifgt: case Bytecodes::_ifle: 1681 case Bytecodes::_if_icmpeq: case Bytecodes::_if_icmpne: 1682 case Bytecodes::_if_icmplt: case Bytecodes::_if_icmpge: 1683 case Bytecodes::_if_icmpgt: case Bytecodes::_if_icmple: 1684 case Bytecodes::_if_acmpeq: case Bytecodes::_if_acmpne: 1685 case Bytecodes::_ifnull: case Bytecodes::_ifnonnull: 1686 // Our successors are the branch target and the next bci. 1687 branch_bci = str->get_dest(); 1688 _successors = 1689 new (arena) GrowableArray<Block*>(arena, 2, 0, nullptr); 1690 assert(_successors->length() == IF_NOT_TAKEN, ""); 1691 _successors->append(analyzer->block_at(next_bci, jsrs)); 1692 assert(_successors->length() == IF_TAKEN, ""); 1693 _successors->append(analyzer->block_at(branch_bci, jsrs)); 1694 break; 1695 1696 case Bytecodes::_goto: 1697 branch_bci = str->get_dest(); 1698 _successors = 1699 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1700 assert(_successors->length() == GOTO_TARGET, ""); 1701 _successors->append(analyzer->block_at(branch_bci, jsrs)); 1702 break; 1703 1704 case Bytecodes::_jsr: 1705 branch_bci = str->get_dest(); 1706 _successors = 1707 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1708 assert(_successors->length() == GOTO_TARGET, ""); 1709 _successors->append(analyzer->block_at(branch_bci, jsrs)); 1710 break; 1711 1712 case Bytecodes::_goto_w: 1713 case Bytecodes::_jsr_w: 1714 _successors = 1715 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1716 assert(_successors->length() == GOTO_TARGET, ""); 1717 _successors->append(analyzer->block_at(str->get_far_dest(), jsrs)); 1718 break; 1719 1720 case Bytecodes::_tableswitch: { 1721 Bytecode_tableswitch tableswitch(str); 1722 1723 int len = tableswitch.length(); 1724 _successors = 1725 new (arena) GrowableArray<Block*>(arena, len+1, 0, nullptr); 1726 int bci = current_bci + tableswitch.default_offset(); 1727 Block* block = analyzer->block_at(bci, jsrs); 1728 assert(_successors->length() == SWITCH_DEFAULT, ""); 1729 _successors->append(block); 1730 while (--len >= 0) { 1731 int bci = current_bci + tableswitch.dest_offset_at(len); 1732 block = analyzer->block_at(bci, jsrs); 1733 assert(_successors->length() >= SWITCH_CASES, ""); 1734 _successors->append_if_missing(block); 1735 } 1736 break; 1737 } 1738 1739 case Bytecodes::_lookupswitch: { 1740 Bytecode_lookupswitch lookupswitch(str); 1741 1742 int npairs = lookupswitch.number_of_pairs(); 1743 _successors = 1744 new (arena) GrowableArray<Block*>(arena, npairs+1, 0, nullptr); 1745 int bci = current_bci + lookupswitch.default_offset(); 1746 Block* block = analyzer->block_at(bci, jsrs); 1747 assert(_successors->length() == SWITCH_DEFAULT, ""); 1748 _successors->append(block); 1749 while(--npairs >= 0) { 1750 LookupswitchPair pair = lookupswitch.pair_at(npairs); 1751 int bci = current_bci + pair.offset(); 1752 Block* block = analyzer->block_at(bci, jsrs); 1753 assert(_successors->length() >= SWITCH_CASES, ""); 1754 _successors->append_if_missing(block); 1755 } 1756 break; 1757 } 1758 1759 case Bytecodes::_athrow: case Bytecodes::_ireturn: 1760 case Bytecodes::_lreturn: case Bytecodes::_freturn: 1761 case Bytecodes::_dreturn: case Bytecodes::_areturn: 1762 case Bytecodes::_return: 1763 _successors = 1764 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1765 // No successors 1766 break; 1767 1768 case Bytecodes::_ret: { 1769 _successors = 1770 new (arena) GrowableArray<Block*>(arena, 1, 0, nullptr); 1771 1772 Cell local = state->local(str->get_index()); 1773 ciType* return_address = state->type_at(local); 1774 assert(return_address->is_return_address(), "verify: wrong type"); 1775 int bci = return_address->as_return_address()->bci(); 1776 assert(_successors->length() == GOTO_TARGET, ""); 1777 _successors->append(analyzer->block_at(bci, jsrs)); 1778 break; 1779 } 1780 1781 case Bytecodes::_wide: 1782 default: 1783 ShouldNotReachHere(); 1784 break; 1785 } 1786 } 1787 1788 // Set predecessor information 1789 for (int i = 0; i < _successors->length(); i++) { 1790 Block* block = _successors->at(i); 1791 block->predecessors()->append(this); 1792 } 1793 } 1794 return _successors; 1795 } 1796 1797 // ------------------------------------------------------------------ 1798 // ciTypeFlow::Block:compute_exceptions 1799 // 1800 // Compute the exceptional successors and types for this Block. 1801 void ciTypeFlow::Block::compute_exceptions() { 1802 assert(_exceptions == nullptr && _exc_klasses == nullptr, "repeat"); 1803 1804 if (CITraceTypeFlow) { 1805 tty->print(">> Computing exceptions for block "); 1806 print_value_on(tty); 1807 tty->cr(); 1808 } 1809 1810 ciTypeFlow* analyzer = outer(); 1811 Arena* arena = analyzer->arena(); 1812 1813 // Any bci in the block will do. 1814 ciExceptionHandlerStream str(analyzer->method(), start()); 1815 1816 // Allocate our growable arrays. 1817 int exc_count = str.count(); 1818 _exceptions = new (arena) GrowableArray<Block*>(arena, exc_count, 0, nullptr); 1819 _exc_klasses = new (arena) GrowableArray<ciInstanceKlass*>(arena, exc_count, 1820 0, nullptr); 1821 1822 for ( ; !str.is_done(); str.next()) { 1823 ciExceptionHandler* handler = str.handler(); 1824 int bci = handler->handler_bci(); 1825 ciInstanceKlass* klass = nullptr; 1826 if (bci == -1) { 1827 // There is no catch all. It is possible to exit the method. 1828 break; 1829 } 1830 if (handler->is_catch_all()) { 1831 klass = analyzer->env()->Throwable_klass(); 1832 } else { 1833 klass = handler->catch_klass(); 1834 } 1835 Block* block = analyzer->block_at(bci, _jsrs); 1836 _exceptions->append(block); 1837 block->predecessors()->append(this); 1838 _exc_klasses->append(klass); 1839 } 1840 } 1841 1842 // ------------------------------------------------------------------ 1843 // ciTypeFlow::Block::set_backedge_copy 1844 // Use this only to make a pre-existing public block into a backedge copy. 1845 void ciTypeFlow::Block::set_backedge_copy(bool z) { 1846 assert(z || (z == is_backedge_copy()), "cannot make a backedge copy public"); 1847 _backedge_copy = z; 1848 } 1849 1850 // Analogous to PhaseIdealLoop::is_in_irreducible_loop 1851 bool ciTypeFlow::Block::is_in_irreducible_loop() const { 1852 if (!outer()->has_irreducible_entry()) { 1853 return false; // No irreducible loop in method. 1854 } 1855 Loop* lp = loop(); // Innermost loop containing block. 1856 if (lp == nullptr) { 1857 assert(!is_post_visited(), "must have enclosing loop once post-visited"); 1858 return false; // Not yet processed, so we do not know, yet. 1859 } 1860 // Walk all the way up the loop-tree, search for an irreducible loop. 1861 do { 1862 if (lp->is_irreducible()) { 1863 return true; // We are in irreducible loop. 1864 } 1865 if (lp->head()->pre_order() == 0) { 1866 return false; // Found root loop, terminate. 1867 } 1868 lp = lp->parent(); 1869 } while (lp != nullptr); 1870 // We have "lp->parent() == nullptr", which happens only for infinite loops, 1871 // where no parent is attached to the loop. We did not find any irreducible 1872 // loop from this block out to lp. Thus lp only has one entry, and no exit 1873 // (it is infinite and reducible). We can always rewrite an infinite loop 1874 // that is nested inside other loops: 1875 // while(condition) { infinite_loop; } 1876 // with an equivalent program where the infinite loop is an outermost loop 1877 // that is not nested in any loop: 1878 // while(condition) { break; } infinite_loop; 1879 // Thus, we can understand lp as an outermost loop, and can terminate and 1880 // conclude: this block is in no irreducible loop. 1881 return false; 1882 } 1883 1884 // ------------------------------------------------------------------ 1885 // ciTypeFlow::Block::is_clonable_exit 1886 // 1887 // At most 2 normal successors, one of which continues looping, 1888 // and all exceptional successors must exit. 1889 bool ciTypeFlow::Block::is_clonable_exit(ciTypeFlow::Loop* lp) { 1890 int normal_cnt = 0; 1891 int in_loop_cnt = 0; 1892 for (SuccIter iter(this); !iter.done(); iter.next()) { 1893 Block* succ = iter.succ(); 1894 if (iter.is_normal_ctrl()) { 1895 if (++normal_cnt > 2) return false; 1896 if (lp->contains(succ->loop())) { 1897 if (++in_loop_cnt > 1) return false; 1898 } 1899 } else { 1900 if (lp->contains(succ->loop())) return false; 1901 } 1902 } 1903 return in_loop_cnt == 1; 1904 } 1905 1906 // ------------------------------------------------------------------ 1907 // ciTypeFlow::Block::looping_succ 1908 // 1909 ciTypeFlow::Block* ciTypeFlow::Block::looping_succ(ciTypeFlow::Loop* lp) { 1910 assert(successors()->length() <= 2, "at most 2 normal successors"); 1911 for (SuccIter iter(this); !iter.done(); iter.next()) { 1912 Block* succ = iter.succ(); 1913 if (lp->contains(succ->loop())) { 1914 return succ; 1915 } 1916 } 1917 return nullptr; 1918 } 1919 1920 #ifndef PRODUCT 1921 // ------------------------------------------------------------------ 1922 // ciTypeFlow::Block::print_value_on 1923 void ciTypeFlow::Block::print_value_on(outputStream* st) const { 1924 if (has_pre_order()) st->print("#%-2d ", pre_order()); 1925 if (has_rpo()) st->print("rpo#%-2d ", rpo()); 1926 st->print("[%d - %d)", start(), limit()); 1927 if (is_loop_head()) st->print(" lphd"); 1928 if (is_in_irreducible_loop()) st->print(" in_irred"); 1929 if (is_irreducible_loop_head()) st->print(" irred_head"); 1930 if (is_irreducible_loop_secondary_entry()) st->print(" irred_entry"); 1931 if (_jsrs->size() > 0) { st->print("/"); _jsrs->print_on(st); } 1932 if (is_backedge_copy()) st->print("/backedge_copy"); 1933 } 1934 1935 // ------------------------------------------------------------------ 1936 // ciTypeFlow::Block::print_on 1937 void ciTypeFlow::Block::print_on(outputStream* st) const { 1938 if ((Verbose || WizardMode) && (limit() >= 0)) { 1939 // Don't print 'dummy' blocks (i.e. blocks with limit() '-1') 1940 outer()->method()->print_codes_on(start(), limit(), st); 1941 } 1942 st->print_cr(" ==================================================== "); 1943 st->print (" "); 1944 print_value_on(st); 1945 st->print(" Stored locals: "); def_locals()->print_on(st, outer()->method()->max_locals()); tty->cr(); 1946 if (loop() && loop()->parent() != nullptr) { 1947 st->print(" loops:"); 1948 Loop* lp = loop(); 1949 do { 1950 st->print(" %d<-%d", lp->head()->pre_order(),lp->tail()->pre_order()); 1951 if (lp->is_irreducible()) st->print("(ir)"); 1952 lp = lp->parent(); 1953 } while (lp->parent() != nullptr); 1954 } 1955 st->cr(); 1956 _state->print_on(st); 1957 if (_successors == nullptr) { 1958 st->print_cr(" No successor information"); 1959 } else { 1960 int num_successors = _successors->length(); 1961 st->print_cr(" Successors : %d", num_successors); 1962 for (int i = 0; i < num_successors; i++) { 1963 Block* successor = _successors->at(i); 1964 st->print(" "); 1965 successor->print_value_on(st); 1966 st->cr(); 1967 } 1968 } 1969 if (_predecessors.is_empty()) { 1970 st->print_cr(" No predecessor information"); 1971 } else { 1972 int num_predecessors = _predecessors.length(); 1973 st->print_cr(" Predecessors : %d", num_predecessors); 1974 for (int i = 0; i < num_predecessors; i++) { 1975 Block* predecessor = _predecessors.at(i); 1976 st->print(" "); 1977 predecessor->print_value_on(st); 1978 st->cr(); 1979 } 1980 } 1981 if (_exceptions == nullptr) { 1982 st->print_cr(" No exception information"); 1983 } else { 1984 int num_exceptions = _exceptions->length(); 1985 st->print_cr(" Exceptions : %d", num_exceptions); 1986 for (int i = 0; i < num_exceptions; i++) { 1987 Block* exc_succ = _exceptions->at(i); 1988 ciInstanceKlass* exc_klass = _exc_klasses->at(i); 1989 st->print(" "); 1990 exc_succ->print_value_on(st); 1991 st->print(" -- "); 1992 exc_klass->name()->print_symbol_on(st); 1993 st->cr(); 1994 } 1995 } 1996 if (has_trap()) { 1997 st->print_cr(" Traps on %d with trap index %d", trap_bci(), trap_index()); 1998 } 1999 st->print_cr(" ==================================================== "); 2000 } 2001 #endif 2002 2003 #ifndef PRODUCT 2004 // ------------------------------------------------------------------ 2005 // ciTypeFlow::LocalSet::print_on 2006 void ciTypeFlow::LocalSet::print_on(outputStream* st, int limit) const { 2007 st->print("{"); 2008 for (int i = 0; i < max; i++) { 2009 if (test(i)) st->print(" %d", i); 2010 } 2011 if (limit > max) { 2012 st->print(" %d..%d ", max, limit); 2013 } 2014 st->print(" }"); 2015 } 2016 #endif 2017 2018 // ciTypeFlow 2019 // 2020 // This is a pass over the bytecodes which computes the following: 2021 // basic block structure 2022 // interpreter type-states (a la the verifier) 2023 2024 // ------------------------------------------------------------------ 2025 // ciTypeFlow::ciTypeFlow 2026 ciTypeFlow::ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci) { 2027 _env = env; 2028 _method = method; 2029 _has_irreducible_entry = false; 2030 _osr_bci = osr_bci; 2031 _failure_reason = nullptr; 2032 assert(0 <= start_bci() && start_bci() < code_size() , "correct osr_bci argument: 0 <= %d < %d", start_bci(), code_size()); 2033 _work_list = nullptr; 2034 2035 int ciblock_count = _method->get_method_blocks()->num_blocks(); 2036 _idx_to_blocklist = NEW_ARENA_ARRAY(arena(), GrowableArray<Block*>*, ciblock_count); 2037 for (int i = 0; i < ciblock_count; i++) { 2038 _idx_to_blocklist[i] = nullptr; 2039 } 2040 _block_map = nullptr; // until all blocks are seen 2041 _jsr_records = nullptr; 2042 } 2043 2044 // ------------------------------------------------------------------ 2045 // ciTypeFlow::work_list_next 2046 // 2047 // Get the next basic block from our work list. 2048 ciTypeFlow::Block* ciTypeFlow::work_list_next() { 2049 assert(!work_list_empty(), "work list must not be empty"); 2050 Block* next_block = _work_list; 2051 _work_list = next_block->next(); 2052 next_block->set_next(nullptr); 2053 next_block->set_on_work_list(false); 2054 return next_block; 2055 } 2056 2057 // ------------------------------------------------------------------ 2058 // ciTypeFlow::add_to_work_list 2059 // 2060 // Add a basic block to our work list. 2061 // List is sorted by decreasing postorder sort (same as increasing RPO) 2062 void ciTypeFlow::add_to_work_list(ciTypeFlow::Block* block) { 2063 assert(!block->is_on_work_list(), "must not already be on work list"); 2064 2065 if (CITraceTypeFlow) { 2066 tty->print(">> Adding block "); 2067 block->print_value_on(tty); 2068 tty->print_cr(" to the work list : "); 2069 } 2070 2071 block->set_on_work_list(true); 2072 2073 // decreasing post order sort 2074 2075 Block* prev = nullptr; 2076 Block* current = _work_list; 2077 int po = block->post_order(); 2078 while (current != nullptr) { 2079 if (!current->has_post_order() || po > current->post_order()) 2080 break; 2081 prev = current; 2082 current = current->next(); 2083 } 2084 if (prev == nullptr) { 2085 block->set_next(_work_list); 2086 _work_list = block; 2087 } else { 2088 block->set_next(current); 2089 prev->set_next(block); 2090 } 2091 2092 if (CITraceTypeFlow) { 2093 tty->cr(); 2094 } 2095 } 2096 2097 // ------------------------------------------------------------------ 2098 // ciTypeFlow::block_at 2099 // 2100 // Return the block beginning at bci which has a JsrSet compatible 2101 // with jsrs. 2102 ciTypeFlow::Block* ciTypeFlow::block_at(int bci, ciTypeFlow::JsrSet* jsrs, CreateOption option) { 2103 // First find the right ciBlock. 2104 if (CITraceTypeFlow) { 2105 tty->print(">> Requesting block for %d/", bci); 2106 jsrs->print_on(tty); 2107 tty->cr(); 2108 } 2109 2110 ciBlock* ciblk = _method->get_method_blocks()->block_containing(bci); 2111 assert(ciblk->start_bci() == bci, "bad ciBlock boundaries"); 2112 Block* block = get_block_for(ciblk->index(), jsrs, option); 2113 2114 assert(block == nullptr? (option == no_create): block->is_backedge_copy() == (option == create_backedge_copy), "create option consistent with result"); 2115 2116 if (CITraceTypeFlow) { 2117 if (block != nullptr) { 2118 tty->print(">> Found block "); 2119 block->print_value_on(tty); 2120 tty->cr(); 2121 } else { 2122 tty->print_cr(">> No such block."); 2123 } 2124 } 2125 2126 return block; 2127 } 2128 2129 // ------------------------------------------------------------------ 2130 // ciTypeFlow::make_jsr_record 2131 // 2132 // Make a JsrRecord for a given (entry, return) pair, if such a record 2133 // does not already exist. 2134 ciTypeFlow::JsrRecord* ciTypeFlow::make_jsr_record(int entry_address, 2135 int return_address) { 2136 if (_jsr_records == nullptr) { 2137 _jsr_records = new (arena()) GrowableArray<JsrRecord*>(arena(), 2138 2, 2139 0, 2140 nullptr); 2141 } 2142 JsrRecord* record = nullptr; 2143 int len = _jsr_records->length(); 2144 for (int i = 0; i < len; i++) { 2145 JsrRecord* record = _jsr_records->at(i); 2146 if (record->entry_address() == entry_address && 2147 record->return_address() == return_address) { 2148 return record; 2149 } 2150 } 2151 2152 record = new (arena()) JsrRecord(entry_address, return_address); 2153 _jsr_records->append(record); 2154 return record; 2155 } 2156 2157 // ------------------------------------------------------------------ 2158 // ciTypeFlow::flow_exceptions 2159 // 2160 // Merge the current state into all exceptional successors at the 2161 // current point in the code. 2162 void ciTypeFlow::flow_exceptions(GrowableArray<ciTypeFlow::Block*>* exceptions, 2163 GrowableArray<ciInstanceKlass*>* exc_klasses, 2164 ciTypeFlow::StateVector* state) { 2165 int len = exceptions->length(); 2166 assert(exc_klasses->length() == len, "must have same length"); 2167 for (int i = 0; i < len; i++) { 2168 Block* block = exceptions->at(i); 2169 ciInstanceKlass* exception_klass = exc_klasses->at(i); 2170 2171 if (!exception_klass->is_loaded()) { 2172 // Do not compile any code for unloaded exception types. 2173 // Following compiler passes are responsible for doing this also. 2174 continue; 2175 } 2176 2177 if (block->meet_exception(exception_klass, state)) { 2178 // Block was modified and has PO. Add it to the work list. 2179 if (block->has_post_order() && 2180 !block->is_on_work_list()) { 2181 add_to_work_list(block); 2182 } 2183 } 2184 } 2185 } 2186 2187 // ------------------------------------------------------------------ 2188 // ciTypeFlow::flow_successors 2189 // 2190 // Merge the current state into all successors at the current point 2191 // in the code. 2192 void ciTypeFlow::flow_successors(GrowableArray<ciTypeFlow::Block*>* successors, 2193 ciTypeFlow::StateVector* state) { 2194 int len = successors->length(); 2195 for (int i = 0; i < len; i++) { 2196 Block* block = successors->at(i); 2197 if (block->meet(state)) { 2198 // Block was modified and has PO. Add it to the work list. 2199 if (block->has_post_order() && 2200 !block->is_on_work_list()) { 2201 add_to_work_list(block); 2202 } 2203 } 2204 } 2205 } 2206 2207 // ------------------------------------------------------------------ 2208 // ciTypeFlow::can_trap 2209 // 2210 // Tells if a given instruction is able to generate an exception edge. 2211 bool ciTypeFlow::can_trap(ciBytecodeStream& str) { 2212 // Cf. GenerateOopMap::do_exception_edge. 2213 if (!Bytecodes::can_trap(str.cur_bc())) return false; 2214 2215 switch (str.cur_bc()) { 2216 case Bytecodes::_ldc: 2217 case Bytecodes::_ldc_w: 2218 case Bytecodes::_ldc2_w: 2219 return str.is_in_error() || !str.get_constant().is_loaded(); 2220 2221 case Bytecodes::_aload_0: 2222 // These bytecodes can trap for rewriting. We need to assume that 2223 // they do not throw exceptions to make the monitor analysis work. 2224 return false; 2225 2226 case Bytecodes::_ireturn: 2227 case Bytecodes::_lreturn: 2228 case Bytecodes::_freturn: 2229 case Bytecodes::_dreturn: 2230 case Bytecodes::_areturn: 2231 case Bytecodes::_return: 2232 // We can assume the monitor stack is empty in this analysis. 2233 return false; 2234 2235 case Bytecodes::_monitorexit: 2236 // We can assume monitors are matched in this analysis. 2237 return false; 2238 2239 default: 2240 return true; 2241 } 2242 } 2243 2244 // ------------------------------------------------------------------ 2245 // ciTypeFlow::clone_loop_heads 2246 // 2247 // Clone the loop heads 2248 bool ciTypeFlow::clone_loop_heads(StateVector* temp_vector, JsrSet* temp_set) { 2249 bool rslt = false; 2250 for (PreorderLoops iter(loop_tree_root()); !iter.done(); iter.next()) { 2251 Loop* lp = iter.current(); 2252 Block* head = lp->head(); 2253 if (lp == loop_tree_root() || 2254 lp->is_irreducible() || 2255 !head->is_clonable_exit(lp)) 2256 continue; 2257 2258 // Avoid BoxLock merge. 2259 if (EliminateNestedLocks && head->has_monitorenter()) 2260 continue; 2261 2262 // check not already cloned 2263 if (head->backedge_copy_count() != 0) 2264 continue; 2265 2266 // Don't clone head of OSR loop to get correct types in start block. 2267 if (is_osr_flow() && head->start() == start_bci()) 2268 continue; 2269 2270 // check _no_ shared head below us 2271 Loop* ch; 2272 for (ch = lp->child(); ch != nullptr && ch->head() != head; ch = ch->sibling()); 2273 if (ch != nullptr) 2274 continue; 2275 2276 // Clone head 2277 Block* new_head = head->looping_succ(lp); 2278 Block* clone = clone_loop_head(lp, temp_vector, temp_set); 2279 // Update lp's info 2280 clone->set_loop(lp); 2281 lp->set_head(new_head); 2282 lp->set_tail(clone); 2283 // And move original head into outer loop 2284 head->set_loop(lp->parent()); 2285 2286 rslt = true; 2287 } 2288 return rslt; 2289 } 2290 2291 // ------------------------------------------------------------------ 2292 // ciTypeFlow::clone_loop_head 2293 // 2294 // Clone lp's head and replace tail's successors with clone. 2295 // 2296 // | 2297 // v 2298 // head <-> body 2299 // | 2300 // v 2301 // exit 2302 // 2303 // new_head 2304 // 2305 // | 2306 // v 2307 // head ----------\ 2308 // | | 2309 // | v 2310 // | clone <-> body 2311 // | | 2312 // | /--/ 2313 // | | 2314 // v v 2315 // exit 2316 // 2317 ciTypeFlow::Block* ciTypeFlow::clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set) { 2318 Block* head = lp->head(); 2319 Block* tail = lp->tail(); 2320 if (CITraceTypeFlow) { 2321 tty->print(">> Requesting clone of loop head "); head->print_value_on(tty); 2322 tty->print(" for predecessor "); tail->print_value_on(tty); 2323 tty->cr(); 2324 } 2325 Block* clone = block_at(head->start(), head->jsrs(), create_backedge_copy); 2326 assert(clone->backedge_copy_count() == 1, "one backedge copy for all back edges"); 2327 2328 assert(!clone->has_pre_order(), "just created"); 2329 clone->set_next_pre_order(); 2330 2331 // Accumulate profiled count for all backedges that share this loop's head 2332 int total_count = lp->profiled_count(); 2333 for (Loop* lp1 = lp->parent(); lp1 != nullptr; lp1 = lp1->parent()) { 2334 for (Loop* lp2 = lp1; lp2 != nullptr; lp2 = lp2->sibling()) { 2335 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) { 2336 total_count += lp2->profiled_count(); 2337 } 2338 } 2339 } 2340 // Have the most frequent ones branch to the clone instead 2341 int count = 0; 2342 int loops_with_shared_head = 0; 2343 Block* latest_tail = tail; 2344 bool done = false; 2345 for (Loop* lp1 = lp; lp1 != nullptr && !done; lp1 = lp1->parent()) { 2346 for (Loop* lp2 = lp1; lp2 != nullptr && !done; lp2 = lp2->sibling()) { 2347 if (lp2->head() == head && !lp2->tail()->is_backedge_copy()) { 2348 count += lp2->profiled_count(); 2349 if (lp2->tail()->post_order() < latest_tail->post_order()) { 2350 latest_tail = lp2->tail(); 2351 } 2352 loops_with_shared_head++; 2353 for (SuccIter iter(lp2->tail()); !iter.done(); iter.next()) { 2354 if (iter.succ() == head) { 2355 iter.set_succ(clone); 2356 // Update predecessor information 2357 head->predecessors()->remove(lp2->tail()); 2358 clone->predecessors()->append(lp2->tail()); 2359 } 2360 } 2361 flow_block(lp2->tail(), temp_vector, temp_set); 2362 if (lp2->head() == lp2->tail()) { 2363 // For self-loops, clone->head becomes clone->clone 2364 flow_block(clone, temp_vector, temp_set); 2365 for (SuccIter iter(clone); !iter.done(); iter.next()) { 2366 if (iter.succ() == lp2->head()) { 2367 iter.set_succ(clone); 2368 // Update predecessor information 2369 lp2->head()->predecessors()->remove(clone); 2370 clone->predecessors()->append(clone); 2371 break; 2372 } 2373 } 2374 } 2375 if (total_count == 0 || count > (total_count * .9)) { 2376 done = true; 2377 } 2378 } 2379 } 2380 } 2381 assert(loops_with_shared_head >= 1, "at least one new"); 2382 clone->set_rpo_next(latest_tail->rpo_next()); 2383 latest_tail->set_rpo_next(clone); 2384 flow_block(clone, temp_vector, temp_set); 2385 2386 return clone; 2387 } 2388 2389 // ------------------------------------------------------------------ 2390 // ciTypeFlow::flow_block 2391 // 2392 // Interpret the effects of the bytecodes on the incoming state 2393 // vector of a basic block. Push the changed state to succeeding 2394 // basic blocks. 2395 void ciTypeFlow::flow_block(ciTypeFlow::Block* block, 2396 ciTypeFlow::StateVector* state, 2397 ciTypeFlow::JsrSet* jsrs) { 2398 if (CITraceTypeFlow) { 2399 tty->print("\n>> ANALYZING BLOCK : "); 2400 tty->cr(); 2401 block->print_on(tty); 2402 } 2403 assert(block->has_pre_order(), "pre-order is assigned before 1st flow"); 2404 2405 int start = block->start(); 2406 int limit = block->limit(); 2407 int control = block->control(); 2408 if (control != ciBlock::fall_through_bci) { 2409 limit = control; 2410 } 2411 2412 // Grab the state from the current block. 2413 block->copy_state_into(state); 2414 state->def_locals()->clear(); 2415 2416 GrowableArray<Block*>* exceptions = block->exceptions(); 2417 GrowableArray<ciInstanceKlass*>* exc_klasses = block->exc_klasses(); 2418 bool has_exceptions = exceptions->length() > 0; 2419 2420 bool exceptions_used = false; 2421 2422 ciBytecodeStream str(method()); 2423 str.reset_to_bci(start); 2424 Bytecodes::Code code; 2425 while ((code = str.next()) != ciBytecodeStream::EOBC() && 2426 str.cur_bci() < limit) { 2427 // Check for exceptional control flow from this point. 2428 if (has_exceptions && can_trap(str)) { 2429 flow_exceptions(exceptions, exc_klasses, state); 2430 exceptions_used = true; 2431 } 2432 // Apply the effects of the current bytecode to our state. 2433 bool res = state->apply_one_bytecode(&str); 2434 2435 // Watch for bailouts. 2436 if (failing()) return; 2437 2438 if (str.cur_bc() == Bytecodes::_monitorenter) { 2439 block->set_has_monitorenter(); 2440 } 2441 2442 if (res) { 2443 2444 // We have encountered a trap. Record it in this block. 2445 block->set_trap(state->trap_bci(), state->trap_index()); 2446 2447 if (CITraceTypeFlow) { 2448 tty->print_cr(">> Found trap"); 2449 block->print_on(tty); 2450 } 2451 2452 // Save set of locals defined in this block 2453 block->def_locals()->add(state->def_locals()); 2454 2455 // Record (no) successors. 2456 block->successors(&str, state, jsrs); 2457 2458 assert(!has_exceptions || exceptions_used, "Not removing exceptions"); 2459 2460 // Discontinue interpretation of this Block. 2461 return; 2462 } 2463 } 2464 2465 GrowableArray<Block*>* successors = nullptr; 2466 if (control != ciBlock::fall_through_bci) { 2467 // Check for exceptional control flow from this point. 2468 if (has_exceptions && can_trap(str)) { 2469 flow_exceptions(exceptions, exc_klasses, state); 2470 exceptions_used = true; 2471 } 2472 2473 // Fix the JsrSet to reflect effect of the bytecode. 2474 block->copy_jsrs_into(jsrs); 2475 jsrs->apply_control(this, &str, state); 2476 2477 // Find successor edges based on old state and new JsrSet. 2478 successors = block->successors(&str, state, jsrs); 2479 2480 // Apply the control changes to the state. 2481 state->apply_one_bytecode(&str); 2482 } else { 2483 // Fall through control 2484 successors = block->successors(&str, nullptr, nullptr); 2485 } 2486 2487 // Save set of locals defined in this block 2488 block->def_locals()->add(state->def_locals()); 2489 2490 // Remove untaken exception paths 2491 if (!exceptions_used) 2492 exceptions->clear(); 2493 2494 // Pass our state to successors. 2495 flow_successors(successors, state); 2496 } 2497 2498 // ------------------------------------------------------------------ 2499 // ciTypeFlow::PreOrderLoops::next 2500 // 2501 // Advance to next loop tree using a preorder, left-to-right traversal. 2502 void ciTypeFlow::PreorderLoops::next() { 2503 assert(!done(), "must not be done."); 2504 if (_current->child() != nullptr) { 2505 _current = _current->child(); 2506 } else if (_current->sibling() != nullptr) { 2507 _current = _current->sibling(); 2508 } else { 2509 while (_current != _root && _current->sibling() == nullptr) { 2510 _current = _current->parent(); 2511 } 2512 if (_current == _root) { 2513 _current = nullptr; 2514 assert(done(), "must be done."); 2515 } else { 2516 assert(_current->sibling() != nullptr, "must be more to do"); 2517 _current = _current->sibling(); 2518 } 2519 } 2520 } 2521 2522 // If the tail is a branch to the head, retrieve how many times that path was taken from profiling 2523 int ciTypeFlow::Loop::profiled_count() { 2524 if (_profiled_count >= 0) { 2525 return _profiled_count; 2526 } 2527 ciMethodData* methodData = outer()->method()->method_data(); 2528 if (!methodData->is_mature()) { 2529 _profiled_count = 0; 2530 return 0; 2531 } 2532 ciTypeFlow::Block* tail = this->tail(); 2533 if (tail->control() == -1 || tail->has_trap()) { 2534 _profiled_count = 0; 2535 return 0; 2536 } 2537 2538 ciProfileData* data = methodData->bci_to_data(tail->control()); 2539 2540 if (data == nullptr || !data->is_JumpData()) { 2541 _profiled_count = 0; 2542 return 0; 2543 } 2544 2545 ciBytecodeStream iter(outer()->method()); 2546 iter.reset_to_bci(tail->control()); 2547 2548 bool is_an_if = false; 2549 bool wide = false; 2550 Bytecodes::Code bc = iter.next(); 2551 switch (bc) { 2552 case Bytecodes::_ifeq: 2553 case Bytecodes::_ifne: 2554 case Bytecodes::_iflt: 2555 case Bytecodes::_ifge: 2556 case Bytecodes::_ifgt: 2557 case Bytecodes::_ifle: 2558 case Bytecodes::_if_icmpeq: 2559 case Bytecodes::_if_icmpne: 2560 case Bytecodes::_if_icmplt: 2561 case Bytecodes::_if_icmpge: 2562 case Bytecodes::_if_icmpgt: 2563 case Bytecodes::_if_icmple: 2564 case Bytecodes::_if_acmpeq: 2565 case Bytecodes::_if_acmpne: 2566 case Bytecodes::_ifnull: 2567 case Bytecodes::_ifnonnull: 2568 is_an_if = true; 2569 break; 2570 case Bytecodes::_goto_w: 2571 case Bytecodes::_jsr_w: 2572 wide = true; 2573 break; 2574 case Bytecodes::_goto: 2575 case Bytecodes::_jsr: 2576 break; 2577 default: 2578 fatal(" invalid bytecode: %s", Bytecodes::name(iter.cur_bc())); 2579 } 2580 2581 GrowableArray<ciTypeFlow::Block*>* succs = tail->successors(); 2582 2583 if (!is_an_if) { 2584 assert(((wide ? iter.get_far_dest() : iter.get_dest()) == head()->start()) == (succs->at(ciTypeFlow::GOTO_TARGET) == head()), "branch should lead to loop head"); 2585 if (succs->at(ciTypeFlow::GOTO_TARGET) == head()) { 2586 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken()); 2587 return _profiled_count; 2588 } 2589 } else { 2590 assert((iter.get_dest() == head()->start()) == (succs->at(ciTypeFlow::IF_TAKEN) == head()), "bytecode and CFG not consistent"); 2591 assert((tail->limit() == head()->start()) == (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()), "bytecode and CFG not consistent"); 2592 if (succs->at(ciTypeFlow::IF_TAKEN) == head()) { 2593 _profiled_count = outer()->method()->scale_count(data->as_JumpData()->taken()); 2594 return _profiled_count; 2595 } else if (succs->at(ciTypeFlow::IF_NOT_TAKEN) == head()) { 2596 _profiled_count = outer()->method()->scale_count(data->as_BranchData()->not_taken()); 2597 return _profiled_count; 2598 } 2599 } 2600 2601 _profiled_count = 0; 2602 return _profiled_count; 2603 } 2604 2605 bool ciTypeFlow::Loop::at_insertion_point(Loop* lp, Loop* current) { 2606 int lp_pre_order = lp->head()->pre_order(); 2607 if (current->head()->pre_order() < lp_pre_order) { 2608 return true; 2609 } else if (current->head()->pre_order() > lp_pre_order) { 2610 return false; 2611 } 2612 // In the case of a shared head, make the most frequent head/tail (as reported by profiling) the inner loop 2613 if (current->head() == lp->head()) { 2614 int lp_count = lp->profiled_count(); 2615 int current_count = current->profiled_count(); 2616 if (current_count < lp_count) { 2617 return true; 2618 } else if (current_count > lp_count) { 2619 return false; 2620 } 2621 } 2622 if (current->tail()->pre_order() > lp->tail()->pre_order()) { 2623 return true; 2624 } 2625 return false; 2626 } 2627 2628 // ------------------------------------------------------------------ 2629 // ciTypeFlow::Loop::sorted_merge 2630 // 2631 // Merge the branch lp into this branch, sorting on the loop head 2632 // pre_orders. Returns the leaf of the merged branch. 2633 // Child and sibling pointers will be setup later. 2634 // Sort is (looking from leaf towards the root) 2635 // descending on primary key: loop head's pre_order, and 2636 // ascending on secondary key: loop tail's pre_order. 2637 ciTypeFlow::Loop* ciTypeFlow::Loop::sorted_merge(Loop* lp) { 2638 Loop* leaf = this; 2639 Loop* prev = nullptr; 2640 Loop* current = leaf; 2641 while (lp != nullptr) { 2642 int lp_pre_order = lp->head()->pre_order(); 2643 // Find insertion point for "lp" 2644 while (current != nullptr) { 2645 if (current == lp) { 2646 return leaf; // Already in list 2647 } 2648 if (at_insertion_point(lp, current)) { 2649 break; 2650 } 2651 prev = current; 2652 current = current->parent(); 2653 } 2654 Loop* next_lp = lp->parent(); // Save future list of items to insert 2655 // Insert lp before current 2656 lp->set_parent(current); 2657 if (prev != nullptr) { 2658 prev->set_parent(lp); 2659 } else { 2660 leaf = lp; 2661 } 2662 prev = lp; // Inserted item is new prev[ious] 2663 lp = next_lp; // Next item to insert 2664 } 2665 return leaf; 2666 } 2667 2668 // ------------------------------------------------------------------ 2669 // ciTypeFlow::build_loop_tree 2670 // 2671 // Incrementally build loop tree. 2672 void ciTypeFlow::build_loop_tree(Block* blk) { 2673 assert(!blk->is_post_visited(), "precondition"); 2674 Loop* innermost = nullptr; // merge of loop tree branches over all successors 2675 2676 for (SuccIter iter(blk); !iter.done(); iter.next()) { 2677 Loop* lp = nullptr; 2678 Block* succ = iter.succ(); 2679 if (!succ->is_post_visited()) { 2680 // Found backedge since predecessor post visited, but successor is not 2681 assert(succ->pre_order() <= blk->pre_order(), "should be backedge"); 2682 2683 // Create a LoopNode to mark this loop. 2684 lp = new (arena()) Loop(succ, blk); 2685 if (succ->loop() == nullptr) 2686 succ->set_loop(lp); 2687 // succ->loop will be updated to innermost loop on a later call, when blk==succ 2688 2689 } else { // Nested loop 2690 lp = succ->loop(); 2691 2692 // If succ is loop head, find outer loop. 2693 while (lp != nullptr && lp->head() == succ) { 2694 lp = lp->parent(); 2695 } 2696 if (lp == nullptr) { 2697 // Infinite loop, it's parent is the root 2698 lp = loop_tree_root(); 2699 } 2700 } 2701 2702 // Check for irreducible loop. 2703 // Successor has already been visited. If the successor's loop head 2704 // has already been post-visited, then this is another entry into the loop. 2705 while (lp->head()->is_post_visited() && lp != loop_tree_root()) { 2706 _has_irreducible_entry = true; 2707 lp->set_irreducible(succ); 2708 if (!succ->is_on_work_list()) { 2709 // Assume irreducible entries need more data flow 2710 add_to_work_list(succ); 2711 } 2712 Loop* plp = lp->parent(); 2713 if (plp == nullptr) { 2714 // This only happens for some irreducible cases. The parent 2715 // will be updated during a later pass. 2716 break; 2717 } 2718 lp = plp; 2719 } 2720 2721 // Merge loop tree branch for all successors. 2722 innermost = innermost == nullptr ? lp : innermost->sorted_merge(lp); 2723 2724 } // end loop 2725 2726 if (innermost == nullptr) { 2727 assert(blk->successors()->length() == 0, "CFG exit"); 2728 blk->set_loop(loop_tree_root()); 2729 } else if (innermost->head() == blk) { 2730 // If loop header, complete the tree pointers 2731 if (blk->loop() != innermost) { 2732 #ifdef ASSERT 2733 assert(blk->loop()->head() == innermost->head(), "same head"); 2734 Loop* dl; 2735 for (dl = innermost; dl != nullptr && dl != blk->loop(); dl = dl->parent()); 2736 assert(dl == blk->loop(), "blk->loop() already in innermost list"); 2737 #endif 2738 blk->set_loop(innermost); 2739 } 2740 innermost->def_locals()->add(blk->def_locals()); 2741 Loop* l = innermost; 2742 Loop* p = l->parent(); 2743 while (p && l->head() == blk) { 2744 l->set_sibling(p->child()); // Put self on parents 'next child' 2745 p->set_child(l); // Make self the first child of parent 2746 p->def_locals()->add(l->def_locals()); 2747 l = p; // Walk up the parent chain 2748 p = l->parent(); 2749 } 2750 } else { 2751 blk->set_loop(innermost); 2752 innermost->def_locals()->add(blk->def_locals()); 2753 } 2754 } 2755 2756 // ------------------------------------------------------------------ 2757 // ciTypeFlow::Loop::contains 2758 // 2759 // Returns true if lp is nested loop. 2760 bool ciTypeFlow::Loop::contains(ciTypeFlow::Loop* lp) const { 2761 assert(lp != nullptr, ""); 2762 if (this == lp || head() == lp->head()) return true; 2763 int depth1 = depth(); 2764 int depth2 = lp->depth(); 2765 if (depth1 > depth2) 2766 return false; 2767 while (depth1 < depth2) { 2768 depth2--; 2769 lp = lp->parent(); 2770 } 2771 return this == lp; 2772 } 2773 2774 // ------------------------------------------------------------------ 2775 // ciTypeFlow::Loop::depth 2776 // 2777 // Loop depth 2778 int ciTypeFlow::Loop::depth() const { 2779 int dp = 0; 2780 for (Loop* lp = this->parent(); lp != nullptr; lp = lp->parent()) 2781 dp++; 2782 return dp; 2783 } 2784 2785 #ifndef PRODUCT 2786 // ------------------------------------------------------------------ 2787 // ciTypeFlow::Loop::print 2788 void ciTypeFlow::Loop::print(outputStream* st, int indent) const { 2789 for (int i = 0; i < indent; i++) st->print(" "); 2790 st->print("%d<-%d %s", 2791 is_root() ? 0 : this->head()->pre_order(), 2792 is_root() ? 0 : this->tail()->pre_order(), 2793 is_irreducible()?" irr":""); 2794 st->print(" defs: "); 2795 def_locals()->print_on(st, _head->outer()->method()->max_locals()); 2796 st->cr(); 2797 for (Loop* ch = child(); ch != nullptr; ch = ch->sibling()) 2798 ch->print(st, indent+2); 2799 } 2800 #endif 2801 2802 // ------------------------------------------------------------------ 2803 // ciTypeFlow::df_flow_types 2804 // 2805 // Perform the depth first type flow analysis. Helper for flow_types. 2806 void ciTypeFlow::df_flow_types(Block* start, 2807 bool do_flow, 2808 StateVector* temp_vector, 2809 JsrSet* temp_set) { 2810 int dft_len = 100; 2811 GrowableArray<Block*> stk(dft_len); 2812 2813 ciBlock* dummy = _method->get_method_blocks()->make_dummy_block(); 2814 JsrSet* root_set = new JsrSet(0); 2815 Block* root_head = new (arena()) Block(this, dummy, root_set); 2816 Block* root_tail = new (arena()) Block(this, dummy, root_set); 2817 root_head->set_pre_order(0); 2818 root_head->set_post_order(0); 2819 root_tail->set_pre_order(max_jint); 2820 root_tail->set_post_order(max_jint); 2821 set_loop_tree_root(new (arena()) Loop(root_head, root_tail)); 2822 2823 stk.push(start); 2824 2825 _next_pre_order = 0; // initialize pre_order counter 2826 _rpo_list = nullptr; 2827 int next_po = 0; // initialize post_order counter 2828 2829 // Compute RPO and the control flow graph 2830 int size; 2831 while ((size = stk.length()) > 0) { 2832 Block* blk = stk.top(); // Leave node on stack 2833 if (!blk->is_visited()) { 2834 // forward arc in graph 2835 assert (!blk->has_pre_order(), ""); 2836 blk->set_next_pre_order(); 2837 2838 if (_next_pre_order >= (int)Compile::current()->max_node_limit() / 2) { 2839 // Too many basic blocks. Bail out. 2840 // This can happen when try/finally constructs are nested to depth N, 2841 // and there is O(2**N) cloning of jsr bodies. See bug 4697245! 2842 // "MaxNodeLimit / 2" is used because probably the parser will 2843 // generate at least twice that many nodes and bail out. 2844 record_failure("too many basic blocks"); 2845 return; 2846 } 2847 if (do_flow) { 2848 flow_block(blk, temp_vector, temp_set); 2849 if (failing()) return; // Watch for bailouts. 2850 } 2851 } else if (!blk->is_post_visited()) { 2852 // cross or back arc 2853 for (SuccIter iter(blk); !iter.done(); iter.next()) { 2854 Block* succ = iter.succ(); 2855 if (!succ->is_visited()) { 2856 stk.push(succ); 2857 } 2858 } 2859 if (stk.length() == size) { 2860 // There were no additional children, post visit node now 2861 stk.pop(); // Remove node from stack 2862 2863 build_loop_tree(blk); 2864 blk->set_post_order(next_po++); // Assign post order 2865 prepend_to_rpo_list(blk); 2866 assert(blk->is_post_visited(), ""); 2867 2868 if (blk->is_loop_head() && !blk->is_on_work_list()) { 2869 // Assume loop heads need more data flow 2870 add_to_work_list(blk); 2871 } 2872 } 2873 } else { 2874 stk.pop(); // Remove post-visited node from stack 2875 } 2876 } 2877 } 2878 2879 // ------------------------------------------------------------------ 2880 // ciTypeFlow::flow_types 2881 // 2882 // Perform the type flow analysis, creating and cloning Blocks as 2883 // necessary. 2884 void ciTypeFlow::flow_types() { 2885 ResourceMark rm; 2886 StateVector* temp_vector = new StateVector(this); 2887 JsrSet* temp_set = new JsrSet(4); 2888 2889 // Create the method entry block. 2890 Block* start = block_at(start_bci(), temp_set); 2891 2892 // Load the initial state into it. 2893 const StateVector* start_state = get_start_state(); 2894 if (failing()) return; 2895 start->meet(start_state); 2896 2897 // Depth first visit 2898 df_flow_types(start, true /*do flow*/, temp_vector, temp_set); 2899 2900 if (failing()) return; 2901 assert(_rpo_list == start, "must be start"); 2902 2903 // Any loops found? 2904 if (loop_tree_root()->child() != nullptr && 2905 env()->comp_level() >= CompLevel_full_optimization) { 2906 // Loop optimizations are not performed on Tier1 compiles. 2907 2908 bool changed = clone_loop_heads(temp_vector, temp_set); 2909 2910 // If some loop heads were cloned, recompute postorder and loop tree 2911 if (changed) { 2912 loop_tree_root()->set_child(nullptr); 2913 for (Block* blk = _rpo_list; blk != nullptr;) { 2914 Block* next = blk->rpo_next(); 2915 blk->df_init(); 2916 blk = next; 2917 } 2918 df_flow_types(start, false /*no flow*/, temp_vector, temp_set); 2919 } 2920 } 2921 2922 if (CITraceTypeFlow) { 2923 tty->print_cr("\nLoop tree"); 2924 loop_tree_root()->print(); 2925 } 2926 2927 // Continue flow analysis until fixed point reached 2928 2929 debug_only(int max_block = _next_pre_order;) 2930 2931 while (!work_list_empty()) { 2932 Block* blk = work_list_next(); 2933 assert (blk->has_post_order(), "post order assigned above"); 2934 2935 flow_block(blk, temp_vector, temp_set); 2936 2937 assert (max_block == _next_pre_order, "no new blocks"); 2938 assert (!failing(), "no more bailouts"); 2939 } 2940 } 2941 2942 // ------------------------------------------------------------------ 2943 // ciTypeFlow::map_blocks 2944 // 2945 // Create the block map, which indexes blocks in reverse post-order. 2946 void ciTypeFlow::map_blocks() { 2947 assert(_block_map == nullptr, "single initialization"); 2948 int block_ct = _next_pre_order; 2949 _block_map = NEW_ARENA_ARRAY(arena(), Block*, block_ct); 2950 assert(block_ct == block_count(), ""); 2951 2952 Block* blk = _rpo_list; 2953 for (int m = 0; m < block_ct; m++) { 2954 int rpo = blk->rpo(); 2955 assert(rpo == m, "should be sequential"); 2956 _block_map[rpo] = blk; 2957 blk = blk->rpo_next(); 2958 } 2959 assert(blk == nullptr, "should be done"); 2960 2961 for (int j = 0; j < block_ct; j++) { 2962 assert(_block_map[j] != nullptr, "must not drop any blocks"); 2963 Block* block = _block_map[j]; 2964 // Remove dead blocks from successor lists: 2965 for (int e = 0; e <= 1; e++) { 2966 GrowableArray<Block*>* l = e? block->exceptions(): block->successors(); 2967 for (int k = 0; k < l->length(); k++) { 2968 Block* s = l->at(k); 2969 if (!s->has_post_order()) { 2970 if (CITraceTypeFlow) { 2971 tty->print("Removing dead %s successor of #%d: ", (e? "exceptional": "normal"), block->pre_order()); 2972 s->print_value_on(tty); 2973 tty->cr(); 2974 } 2975 l->remove(s); 2976 --k; 2977 } 2978 } 2979 } 2980 } 2981 } 2982 2983 // ------------------------------------------------------------------ 2984 // ciTypeFlow::get_block_for 2985 // 2986 // Find a block with this ciBlock which has a compatible JsrSet. 2987 // If no such block exists, create it, unless the option is no_create. 2988 // If the option is create_backedge_copy, always create a fresh backedge copy. 2989 ciTypeFlow::Block* ciTypeFlow::get_block_for(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs, CreateOption option) { 2990 Arena* a = arena(); 2991 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex]; 2992 if (blocks == nullptr) { 2993 // Query only? 2994 if (option == no_create) return nullptr; 2995 2996 // Allocate the growable array. 2997 blocks = new (a) GrowableArray<Block*>(a, 4, 0, nullptr); 2998 _idx_to_blocklist[ciBlockIndex] = blocks; 2999 } 3000 3001 if (option != create_backedge_copy) { 3002 int len = blocks->length(); 3003 for (int i = 0; i < len; i++) { 3004 Block* block = blocks->at(i); 3005 if (!block->is_backedge_copy() && block->is_compatible_with(jsrs)) { 3006 return block; 3007 } 3008 } 3009 } 3010 3011 // Query only? 3012 if (option == no_create) return nullptr; 3013 3014 // We did not find a compatible block. Create one. 3015 Block* new_block = new (a) Block(this, _method->get_method_blocks()->block(ciBlockIndex), jsrs); 3016 if (option == create_backedge_copy) new_block->set_backedge_copy(true); 3017 blocks->append(new_block); 3018 return new_block; 3019 } 3020 3021 // ------------------------------------------------------------------ 3022 // ciTypeFlow::backedge_copy_count 3023 // 3024 int ciTypeFlow::backedge_copy_count(int ciBlockIndex, ciTypeFlow::JsrSet* jsrs) const { 3025 GrowableArray<Block*>* blocks = _idx_to_blocklist[ciBlockIndex]; 3026 3027 if (blocks == nullptr) { 3028 return 0; 3029 } 3030 3031 int count = 0; 3032 int len = blocks->length(); 3033 for (int i = 0; i < len; i++) { 3034 Block* block = blocks->at(i); 3035 if (block->is_backedge_copy() && block->is_compatible_with(jsrs)) { 3036 count++; 3037 } 3038 } 3039 3040 return count; 3041 } 3042 3043 // ------------------------------------------------------------------ 3044 // ciTypeFlow::do_flow 3045 // 3046 // Perform type inference flow analysis. 3047 void ciTypeFlow::do_flow() { 3048 if (CITraceTypeFlow) { 3049 tty->print_cr("\nPerforming flow analysis on method"); 3050 method()->print(); 3051 if (is_osr_flow()) tty->print(" at OSR bci %d", start_bci()); 3052 tty->cr(); 3053 method()->print_codes(); 3054 } 3055 if (CITraceTypeFlow) { 3056 tty->print_cr("Initial CI Blocks"); 3057 print_on(tty); 3058 } 3059 flow_types(); 3060 // Watch for bailouts. 3061 if (failing()) { 3062 return; 3063 } 3064 3065 map_blocks(); 3066 3067 if (CIPrintTypeFlow || CITraceTypeFlow) { 3068 rpo_print_on(tty); 3069 } 3070 } 3071 3072 // ------------------------------------------------------------------ 3073 // ciTypeFlow::is_dominated_by 3074 // 3075 // Determine if the instruction at bci is dominated by the instruction at dom_bci. 3076 bool ciTypeFlow::is_dominated_by(int bci, int dom_bci) { 3077 assert(!method()->has_jsrs(), "jsrs are not supported"); 3078 3079 ResourceMark rm; 3080 JsrSet* jsrs = new ciTypeFlow::JsrSet(); 3081 int index = _method->get_method_blocks()->block_containing(bci)->index(); 3082 int dom_index = _method->get_method_blocks()->block_containing(dom_bci)->index(); 3083 Block* block = get_block_for(index, jsrs, ciTypeFlow::no_create); 3084 Block* dom_block = get_block_for(dom_index, jsrs, ciTypeFlow::no_create); 3085 3086 // Start block dominates all other blocks 3087 if (start_block()->rpo() == dom_block->rpo()) { 3088 return true; 3089 } 3090 3091 // Dominated[i] is true if block i is dominated by dom_block 3092 int num_blocks = block_count(); 3093 bool* dominated = NEW_RESOURCE_ARRAY(bool, num_blocks); 3094 for (int i = 0; i < num_blocks; ++i) { 3095 dominated[i] = true; 3096 } 3097 dominated[start_block()->rpo()] = false; 3098 3099 // Iterative dominator algorithm 3100 bool changed = true; 3101 while (changed) { 3102 changed = false; 3103 // Use reverse postorder iteration 3104 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) { 3105 if (blk->is_start()) { 3106 // Ignore start block 3107 continue; 3108 } 3109 // The block is dominated if it is the dominating block 3110 // itself or if all predecessors are dominated. 3111 int index = blk->rpo(); 3112 bool dom = (index == dom_block->rpo()); 3113 if (!dom) { 3114 // Check if all predecessors are dominated 3115 dom = true; 3116 for (int i = 0; i < blk->predecessors()->length(); ++i) { 3117 Block* pred = blk->predecessors()->at(i); 3118 if (!dominated[pred->rpo()]) { 3119 dom = false; 3120 break; 3121 } 3122 } 3123 } 3124 // Update dominator information 3125 if (dominated[index] != dom) { 3126 changed = true; 3127 dominated[index] = dom; 3128 } 3129 } 3130 } 3131 // block dominated by dom_block? 3132 return dominated[block->rpo()]; 3133 } 3134 3135 // ------------------------------------------------------------------ 3136 // ciTypeFlow::record_failure() 3137 // The ciTypeFlow object keeps track of failure reasons separately from the ciEnv. 3138 // This is required because there is not a 1-1 relation between the ciEnv and 3139 // the TypeFlow passes within a compilation task. For example, if the compiler 3140 // is considering inlining a method, it will request a TypeFlow. If that fails, 3141 // the compilation as a whole may continue without the inlining. Some TypeFlow 3142 // requests are not optional; if they fail the requestor is responsible for 3143 // copying the failure reason up to the ciEnv. (See Parse::Parse.) 3144 void ciTypeFlow::record_failure(const char* reason) { 3145 if (env()->log() != nullptr) { 3146 env()->log()->elem("failure reason='%s' phase='typeflow'", reason); 3147 } 3148 if (_failure_reason == nullptr) { 3149 // Record the first failure reason. 3150 _failure_reason = reason; 3151 } 3152 } 3153 3154 #ifndef PRODUCT 3155 void ciTypeFlow::print() const { print_on(tty); } 3156 3157 // ------------------------------------------------------------------ 3158 // ciTypeFlow::print_on 3159 void ciTypeFlow::print_on(outputStream* st) const { 3160 // Walk through CI blocks 3161 st->print_cr("********************************************************"); 3162 st->print ("TypeFlow for "); 3163 method()->name()->print_symbol_on(st); 3164 int limit_bci = code_size(); 3165 st->print_cr(" %d bytes", limit_bci); 3166 ciMethodBlocks* mblks = _method->get_method_blocks(); 3167 ciBlock* current = nullptr; 3168 for (int bci = 0; bci < limit_bci; bci++) { 3169 ciBlock* blk = mblks->block_containing(bci); 3170 if (blk != nullptr && blk != current) { 3171 current = blk; 3172 current->print_on(st); 3173 3174 GrowableArray<Block*>* blocks = _idx_to_blocklist[blk->index()]; 3175 int num_blocks = (blocks == nullptr) ? 0 : blocks->length(); 3176 3177 if (num_blocks == 0) { 3178 st->print_cr(" No Blocks"); 3179 } else { 3180 for (int i = 0; i < num_blocks; i++) { 3181 Block* block = blocks->at(i); 3182 block->print_on(st); 3183 } 3184 } 3185 st->print_cr("--------------------------------------------------------"); 3186 st->cr(); 3187 } 3188 } 3189 st->print_cr("********************************************************"); 3190 st->cr(); 3191 } 3192 3193 void ciTypeFlow::rpo_print_on(outputStream* st) const { 3194 st->print_cr("********************************************************"); 3195 st->print ("TypeFlow for "); 3196 method()->name()->print_symbol_on(st); 3197 int limit_bci = code_size(); 3198 st->print_cr(" %d bytes", limit_bci); 3199 for (Block* blk = _rpo_list; blk != nullptr; blk = blk->rpo_next()) { 3200 blk->print_on(st); 3201 st->print_cr("--------------------------------------------------------"); 3202 st->cr(); 3203 } 3204 st->print_cr("********************************************************"); 3205 st->cr(); 3206 } 3207 #endif --- EOF ---