1 /* 2 * Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CI_CITYPEFLOW_HPP 26 #define SHARE_VM_CI_CITYPEFLOW_HPP 27 28 #ifdef COMPILER2 29 #include "ci/ciEnv.hpp" 30 #include "ci/ciKlass.hpp" 31 #include "ci/ciMethodBlocks.hpp" 32 #endif 33 #ifdef SHARK 34 #include "ci/ciEnv.hpp" 35 #include "ci/ciKlass.hpp" 36 #include "ci/ciMethodBlocks.hpp" 37 #include "shark/shark_globals.hpp" 38 #endif 39 40 41 class ciTypeFlow : public ResourceObj { 42 private: 43 ciEnv* _env; 44 ciMethod* _method; 45 ciMethodBlocks* _methodBlocks; 46 int _osr_bci; 47 48 // information cached from the method: 49 int _max_locals; 50 int _max_stack; 51 int _code_size; 52 bool _has_irreducible_entry; 53 54 const char* _failure_reason; 55 56 public: 57 class StateVector; 58 class Loop; 59 class Block; 60 61 // Build a type flow analyzer 62 // Do an OSR analysis if osr_bci >= 0. 63 ciTypeFlow(ciEnv* env, ciMethod* method, int osr_bci = InvocationEntryBci); 64 65 // Accessors 66 ciMethod* method() const { return _method; } 67 ciEnv* env() { return _env; } 68 Arena* arena() { return _env->arena(); } 69 bool is_osr_flow() const{ return _osr_bci != InvocationEntryBci; } 70 int start_bci() const { return is_osr_flow()? _osr_bci: 0; } 71 int max_locals() const { return _max_locals; } 72 int max_stack() const { return _max_stack; } 73 int max_cells() const { return _max_locals + _max_stack; } 74 int code_size() const { return _code_size; } 75 bool has_irreducible_entry() const { return _has_irreducible_entry; } 76 77 // Represents information about an "active" jsr call. This 78 // class represents a call to the routine at some entry address 79 // with some distinct return address. 80 class JsrRecord : public ResourceObj { 81 private: 82 int _entry_address; 83 int _return_address; 84 public: 85 JsrRecord(int entry_address, int return_address) { 86 _entry_address = entry_address; 87 _return_address = return_address; 88 } 89 90 int entry_address() const { return _entry_address; } 91 int return_address() const { return _return_address; } 92 93 void print_on(outputStream* st) const { 94 #ifndef PRODUCT 95 st->print("%d->%d", entry_address(), return_address()); 96 #endif 97 } 98 }; 99 100 // A JsrSet represents some set of JsrRecords. This class 101 // is used to record a set of all jsr routines which we permit 102 // execution to return (ret) from. 103 // 104 // During abstract interpretation, JsrSets are used to determine 105 // whether two paths which reach a given block are unique, and 106 // should be cloned apart, or are compatible, and should merge 107 // together. 108 // 109 // Note that different amounts of effort can be expended determining 110 // if paths are compatible. <DISCUSSION> 111 class JsrSet : public ResourceObj { 112 private: 113 GrowableArray<JsrRecord*>* _set; 114 115 JsrRecord* record_at(int i) { 116 return _set->at(i); 117 } 118 119 // Insert the given JsrRecord into the JsrSet, maintaining the order 120 // of the set and replacing any element with the same entry address. 121 void insert_jsr_record(JsrRecord* record); 122 123 // Remove the JsrRecord with the given return address from the JsrSet. 124 void remove_jsr_record(int return_address); 125 126 public: 127 JsrSet(Arena* arena, int default_len = 4); 128 129 // Copy this JsrSet. 130 void copy_into(JsrSet* jsrs); 131 132 // Is this JsrSet compatible with some other JsrSet? 133 bool is_compatible_with(JsrSet* other); 134 135 // Apply the effect of a single bytecode to the JsrSet. 136 void apply_control(ciTypeFlow* analyzer, 137 ciBytecodeStream* str, 138 StateVector* state); 139 140 // What is the cardinality of this set? 141 int size() const { return _set->length(); } 142 143 void print_on(outputStream* st) const PRODUCT_RETURN; 144 }; 145 146 class LocalSet VALUE_OBJ_CLASS_SPEC { 147 private: 148 enum Constants { max = 63 }; 149 uint64_t _bits; 150 public: 151 LocalSet() : _bits(0) {} 152 void add(uint32_t i) { if (i < (uint32_t)max) _bits |= (1LL << i); } 153 void add(LocalSet* ls) { _bits |= ls->_bits; } 154 bool test(uint32_t i) const { return i < (uint32_t)max ? (_bits>>i)&1U : true; } 155 void clear() { _bits = 0; } 156 void print_on(outputStream* st, int limit) const PRODUCT_RETURN; 157 }; 158 159 // Used as a combined index for locals and temps 160 enum Cell { 161 Cell_0, Cell_max = INT_MAX 162 }; 163 164 // A StateVector summarizes the type information at some 165 // point in the program 166 class StateVector : public ResourceObj { 167 private: 168 ciType** _types; 169 int _stack_size; 170 int _monitor_count; 171 ciTypeFlow* _outer; 172 173 int _trap_bci; 174 int _trap_index; 175 176 LocalSet _def_locals; // For entire block 177 178 static ciType* type_meet_internal(ciType* t1, ciType* t2, ciTypeFlow* analyzer); 179 180 public: 181 // Special elements in our type lattice. 182 enum { 183 T_TOP = T_VOID, // why not? 184 T_BOTTOM = T_CONFLICT, 185 T_LONG2 = T_SHORT, // 2nd word of T_LONG 186 T_DOUBLE2 = T_CHAR, // 2nd word of T_DOUBLE 187 T_NULL = T_BYTE // for now. 188 }; 189 static ciType* top_type() { return ciType::make((BasicType)T_TOP); } 190 static ciType* bottom_type() { return ciType::make((BasicType)T_BOTTOM); } 191 static ciType* long2_type() { return ciType::make((BasicType)T_LONG2); } 192 static ciType* double2_type(){ return ciType::make((BasicType)T_DOUBLE2); } 193 static ciType* null_type() { return ciType::make((BasicType)T_NULL); } 194 195 static ciType* half_type(ciType* t) { 196 switch (t->basic_type()) { 197 case T_LONG: return long2_type(); 198 case T_DOUBLE: return double2_type(); 199 default: ShouldNotReachHere(); return NULL; 200 } 201 } 202 203 // The meet operation for our type lattice. 204 ciType* type_meet(ciType* t1, ciType* t2) { 205 return type_meet_internal(t1, t2, outer()); 206 } 207 208 // Accessors 209 ciTypeFlow* outer() const { return _outer; } 210 211 int stack_size() const { return _stack_size; } 212 void set_stack_size(int ss) { _stack_size = ss; } 213 214 int monitor_count() const { return _monitor_count; } 215 void set_monitor_count(int mc) { _monitor_count = mc; } 216 217 LocalSet* def_locals() { return &_def_locals; } 218 const LocalSet* def_locals() const { return &_def_locals; } 219 220 static Cell start_cell() { return (Cell)0; } 221 static Cell next_cell(Cell c) { return (Cell)(((int)c) + 1); } 222 Cell limit_cell() const { 223 return (Cell)(outer()->max_locals() + stack_size()); 224 } 225 226 // Cell creation 227 Cell local(int lnum) const { 228 assert(lnum < outer()->max_locals(), "index check"); 229 return (Cell)(lnum); 230 } 231 232 Cell stack(int snum) const { 233 assert(snum < stack_size(), "index check"); 234 return (Cell)(outer()->max_locals() + snum); 235 } 236 237 Cell tos() const { return stack(stack_size()-1); } 238 239 // For external use only: 240 ciType* local_type_at(int i) const { return type_at(local(i)); } 241 ciType* stack_type_at(int i) const { return type_at(stack(i)); } 242 243 // Accessors for the type of some Cell c 244 ciType* type_at(Cell c) const { 245 assert(start_cell() <= c && c < limit_cell(), "out of bounds"); 246 return _types[c]; 247 } 248 249 void set_type_at(Cell c, ciType* type) { 250 assert(start_cell() <= c && c < limit_cell(), "out of bounds"); 251 _types[c] = type; 252 } 253 254 // Top-of-stack operations. 255 void set_type_at_tos(ciType* type) { set_type_at(tos(), type); } 256 ciType* type_at_tos() const { return type_at(tos()); } 257 258 void push(ciType* type) { 259 _stack_size++; 260 set_type_at_tos(type); 261 } 262 void pop() { 263 debug_only(set_type_at_tos(bottom_type())); 264 _stack_size--; 265 } 266 ciType* pop_value() { 267 ciType* t = type_at_tos(); 268 pop(); 269 return t; 270 } 271 272 // Convenience operations. 273 bool is_reference(ciType* type) const { 274 return type == null_type() || !type->is_primitive_type(); 275 } 276 bool is_int(ciType* type) const { 277 return type->basic_type() == T_INT; 278 } 279 bool is_long(ciType* type) const { 280 return type->basic_type() == T_LONG; 281 } 282 bool is_float(ciType* type) const { 283 return type->basic_type() == T_FLOAT; 284 } 285 bool is_double(ciType* type) const { 286 return type->basic_type() == T_DOUBLE; 287 } 288 289 void store_to_local(int lnum) { 290 _def_locals.add((uint) lnum); 291 } 292 293 void push_translate(ciType* type); 294 295 void push_int() { 296 push(ciType::make(T_INT)); 297 } 298 void pop_int() { 299 assert(is_int(type_at_tos()), "must be integer"); 300 pop(); 301 } 302 void check_int(Cell c) { 303 assert(is_int(type_at(c)), "must be integer"); 304 } 305 void push_double() { 306 push(ciType::make(T_DOUBLE)); 307 push(double2_type()); 308 } 309 void pop_double() { 310 assert(type_at_tos() == double2_type(), "must be 2nd half"); 311 pop(); 312 assert(is_double(type_at_tos()), "must be double"); 313 pop(); 314 } 315 void push_float() { 316 push(ciType::make(T_FLOAT)); 317 } 318 void pop_float() { 319 assert(is_float(type_at_tos()), "must be float"); 320 pop(); 321 } 322 void push_long() { 323 push(ciType::make(T_LONG)); 324 push(long2_type()); 325 } 326 void pop_long() { 327 assert(type_at_tos() == long2_type(), "must be 2nd half"); 328 pop(); 329 assert(is_long(type_at_tos()), "must be long"); 330 pop(); 331 } 332 void push_object(ciKlass* klass) { 333 push(klass); 334 } 335 void pop_object() { 336 assert(is_reference(type_at_tos()), "must be reference type"); 337 pop(); 338 } 339 void pop_array() { 340 assert(type_at_tos() == null_type() || 341 type_at_tos()->is_array_klass(), "must be array type"); 342 pop(); 343 } 344 // pop_valueOrobjArray and pop_typeArray narrow the tos to ciObjArrayKlass, 345 // ciValueArrayKlass or ciTypeArrayKlass (resp.). In the rare case that an explicit 346 // null is popped from the stack, we return NULL. Caller beware. 347 ciArrayKlass* pop_objOrValueArray() { 348 ciType* array = pop_value(); 349 if (array == null_type()) return NULL; 350 // Value type arrays may contain oop or flattened representation 351 assert(array->is_obj_array_klass() || (ValueArrayFlatten && array->is_value_array_klass()), 352 "must be value or object array type"); 353 return array->as_array_klass(); 354 } 355 ciTypeArrayKlass* pop_typeArray() { 356 ciType* array = pop_value(); 357 if (array == null_type()) return NULL; 358 assert(array->is_type_array_klass(), "must be prim array type"); 359 return array->as_type_array_klass(); 360 } 361 void push_null() { 362 push(null_type()); 363 } 364 void do_null_assert(ciKlass* unloaded_klass); 365 366 // Helper convenience routines. 367 void do_aload(ciBytecodeStream* str); 368 void do_checkcast(ciBytecodeStream* str); 369 void do_getfield(ciBytecodeStream* str); 370 void do_getstatic(ciBytecodeStream* str); 371 void do_invoke(ciBytecodeStream* str, bool has_receiver); 372 void do_jsr(ciBytecodeStream* str); 373 void do_ldc(ciBytecodeStream* str); 374 void do_multianewarray(ciBytecodeStream* str); 375 void do_new(ciBytecodeStream* str); 376 void do_vnew(ciBytecodeStream* str); 377 void do_newarray(ciBytecodeStream* str); 378 void do_putfield(ciBytecodeStream* str); 379 void do_putstatic(ciBytecodeStream* str); 380 void do_ret(ciBytecodeStream* str); 381 void do_vunbox(ciBytecodeStream* str); 382 void do_vbox(ciBytecodeStream* str); 383 384 void overwrite_local_double_long(int index) { 385 // Invalidate the previous local if it contains first half of 386 // a double or long value since it's seconf half is being overwritten. 387 int prev_index = index - 1; 388 if (prev_index >= 0 && 389 (is_double(type_at(local(prev_index))) || 390 is_long(type_at(local(prev_index))))) { 391 set_type_at(local(prev_index), bottom_type()); 392 } 393 } 394 395 void load_local_object(int index) { 396 ciType* type = type_at(local(index)); 397 assert(is_reference(type), "must be reference type"); 398 push(type); 399 } 400 void store_local_object(int index) { 401 ciType* type = pop_value(); 402 assert(is_reference(type) || type->is_return_address(), 403 "must be reference type or return address"); 404 overwrite_local_double_long(index); 405 set_type_at(local(index), type); 406 store_to_local(index); 407 } 408 409 void load_local_double(int index) { 410 ciType* type = type_at(local(index)); 411 ciType* type2 = type_at(local(index+1)); 412 assert(is_double(type), "must be double type"); 413 assert(type2 == double2_type(), "must be 2nd half"); 414 push(type); 415 push(double2_type()); 416 } 417 void store_local_double(int index) { 418 ciType* type2 = pop_value(); 419 ciType* type = pop_value(); 420 assert(is_double(type), "must be double"); 421 assert(type2 == double2_type(), "must be 2nd half"); 422 overwrite_local_double_long(index); 423 set_type_at(local(index), type); 424 set_type_at(local(index+1), type2); 425 store_to_local(index); 426 store_to_local(index+1); 427 } 428 429 void load_local_float(int index) { 430 ciType* type = type_at(local(index)); 431 assert(is_float(type), "must be float type"); 432 push(type); 433 } 434 void store_local_float(int index) { 435 ciType* type = pop_value(); 436 assert(is_float(type), "must be float type"); 437 overwrite_local_double_long(index); 438 set_type_at(local(index), type); 439 store_to_local(index); 440 } 441 442 void load_local_int(int index) { 443 ciType* type = type_at(local(index)); 444 assert(is_int(type), "must be int type"); 445 push(type); 446 } 447 void store_local_int(int index) { 448 ciType* type = pop_value(); 449 assert(is_int(type), "must be int type"); 450 overwrite_local_double_long(index); 451 set_type_at(local(index), type); 452 store_to_local(index); 453 } 454 455 void load_local_long(int index) { 456 ciType* type = type_at(local(index)); 457 ciType* type2 = type_at(local(index+1)); 458 assert(is_long(type), "must be long type"); 459 assert(type2 == long2_type(), "must be 2nd half"); 460 push(type); 461 push(long2_type()); 462 } 463 void store_local_long(int index) { 464 ciType* type2 = pop_value(); 465 ciType* type = pop_value(); 466 assert(is_long(type), "must be long"); 467 assert(type2 == long2_type(), "must be 2nd half"); 468 overwrite_local_double_long(index); 469 set_type_at(local(index), type); 470 set_type_at(local(index+1), type2); 471 store_to_local(index); 472 store_to_local(index+1); 473 } 474 475 // Stop interpretation of this path with a trap. 476 void trap(ciBytecodeStream* str, ciKlass* klass, int index); 477 478 public: 479 StateVector(ciTypeFlow* outer); 480 481 // Copy our value into some other StateVector 482 void copy_into(StateVector* copy) const; 483 484 // Meets this StateVector with another, destructively modifying this 485 // one. Returns true if any modification takes place. 486 bool meet(const StateVector* incoming); 487 488 // Ditto, except that the incoming state is coming from an exception. 489 bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming); 490 491 // Apply the effect of one bytecode to this StateVector 492 bool apply_one_bytecode(ciBytecodeStream* stream); 493 494 // What is the bci of the trap? 495 int trap_bci() { return _trap_bci; } 496 497 // What is the index associated with the trap? 498 int trap_index() { return _trap_index; } 499 500 void print_cell_on(outputStream* st, Cell c) const PRODUCT_RETURN; 501 void print_on(outputStream* st) const PRODUCT_RETURN; 502 }; 503 504 // Parameter for "find_block" calls: 505 // Describes the difference between a public and backedge copy. 506 enum CreateOption { 507 create_public_copy, 508 create_backedge_copy, 509 no_create 510 }; 511 512 // Successor iterator 513 class SuccIter : public StackObj { 514 private: 515 Block* _pred; 516 int _index; 517 Block* _succ; 518 public: 519 SuccIter() : _pred(NULL), _index(-1), _succ(NULL) {} 520 SuccIter(Block* pred) : _pred(pred), _index(-1), _succ(NULL) { next(); } 521 int index() { return _index; } 522 Block* pred() { return _pred; } // Return predecessor 523 bool done() { return _index < 0; } // Finished? 524 Block* succ() { return _succ; } // Return current successor 525 void next(); // Advance 526 void set_succ(Block* succ); // Update current successor 527 bool is_normal_ctrl() { return index() < _pred->successors()->length(); } 528 }; 529 530 // A basic block 531 class Block : public ResourceObj { 532 private: 533 ciBlock* _ciblock; 534 GrowableArray<Block*>* _exceptions; 535 GrowableArray<ciInstanceKlass*>* _exc_klasses; 536 GrowableArray<Block*>* _successors; 537 GrowableArray<Block*>* _predecessors; 538 StateVector* _state; 539 JsrSet* _jsrs; 540 541 int _trap_bci; 542 int _trap_index; 543 544 // pre_order, assigned at first visit. Used as block ID and "visited" tag 545 int _pre_order; 546 547 // A post-order, used to compute the reverse post order (RPO) provided to the client 548 int _post_order; // used to compute rpo 549 550 // Has this block been cloned for a loop backedge? 551 bool _backedge_copy; 552 553 // This block is entry to irreducible loop. 554 bool _irreducible_entry; 555 556 // This block has monitor entry point. 557 bool _has_monitorenter; 558 559 // A pointer used for our internal work list 560 bool _on_work_list; // on the work list 561 Block* _next; 562 Block* _rpo_next; // Reverse post order list 563 564 // Loop info 565 Loop* _loop; // nearest loop 566 567 ciBlock* ciblock() const { return _ciblock; } 568 StateVector* state() const { return _state; } 569 570 // Compute the exceptional successors and types for this Block. 571 void compute_exceptions(); 572 573 public: 574 // constructors 575 Block(ciTypeFlow* outer, ciBlock* ciblk, JsrSet* jsrs); 576 577 void set_trap(int trap_bci, int trap_index) { 578 _trap_bci = trap_bci; 579 _trap_index = trap_index; 580 assert(has_trap(), ""); 581 } 582 bool has_trap() const { return _trap_bci != -1; } 583 int trap_bci() const { assert(has_trap(), ""); return _trap_bci; } 584 int trap_index() const { assert(has_trap(), ""); return _trap_index; } 585 586 // accessors 587 ciTypeFlow* outer() const { return state()->outer(); } 588 int start() const { return _ciblock->start_bci(); } 589 int limit() const { return _ciblock->limit_bci(); } 590 int control() const { return _ciblock->control_bci(); } 591 JsrSet* jsrs() const { return _jsrs; } 592 593 bool is_backedge_copy() const { return _backedge_copy; } 594 void set_backedge_copy(bool z); 595 int backedge_copy_count() const { return outer()->backedge_copy_count(ciblock()->index(), _jsrs); } 596 597 // access to entry state 598 int stack_size() const { return _state->stack_size(); } 599 int monitor_count() const { return _state->monitor_count(); } 600 ciType* local_type_at(int i) const { return _state->local_type_at(i); } 601 ciType* stack_type_at(int i) const { return _state->stack_type_at(i); } 602 603 // Data flow on locals 604 bool is_invariant_local(uint v) const { 605 assert(is_loop_head(), "only loop heads"); 606 // Find outermost loop with same loop head 607 Loop* lp = loop(); 608 while (lp->parent() != NULL) { 609 if (lp->parent()->head() != lp->head()) break; 610 lp = lp->parent(); 611 } 612 return !lp->def_locals()->test(v); 613 } 614 LocalSet* def_locals() { return _state->def_locals(); } 615 const LocalSet* def_locals() const { return _state->def_locals(); } 616 617 // Get the successors for this Block. 618 GrowableArray<Block*>* successors(ciBytecodeStream* str, 619 StateVector* state, 620 JsrSet* jsrs); 621 GrowableArray<Block*>* successors() { 622 assert(_successors != NULL, "must be filled in"); 623 return _successors; 624 } 625 626 // Predecessors of this block (including exception edges) 627 GrowableArray<Block*>* predecessors() { 628 assert(_predecessors != NULL, "must be filled in"); 629 return _predecessors; 630 } 631 632 // Get the exceptional successors for this Block. 633 GrowableArray<Block*>* exceptions() { 634 if (_exceptions == NULL) { 635 compute_exceptions(); 636 } 637 return _exceptions; 638 } 639 640 // Get the exception klasses corresponding to the 641 // exceptional successors for this Block. 642 GrowableArray<ciInstanceKlass*>* exc_klasses() { 643 if (_exc_klasses == NULL) { 644 compute_exceptions(); 645 } 646 return _exc_klasses; 647 } 648 649 // Is this Block compatible with a given JsrSet? 650 bool is_compatible_with(JsrSet* other) { 651 return _jsrs->is_compatible_with(other); 652 } 653 654 // Copy the value of our state vector into another. 655 void copy_state_into(StateVector* copy) const { 656 _state->copy_into(copy); 657 } 658 659 // Copy the value of our JsrSet into another 660 void copy_jsrs_into(JsrSet* copy) const { 661 _jsrs->copy_into(copy); 662 } 663 664 // Meets the start state of this block with another state, destructively 665 // modifying this one. Returns true if any modification takes place. 666 bool meet(const StateVector* incoming) { 667 return state()->meet(incoming); 668 } 669 670 // Ditto, except that the incoming state is coming from an 671 // exception path. This means the stack is replaced by the 672 // appropriate exception type. 673 bool meet_exception(ciInstanceKlass* exc, const StateVector* incoming) { 674 return state()->meet_exception(exc, incoming); 675 } 676 677 // Work list manipulation 678 void set_next(Block* block) { _next = block; } 679 Block* next() const { return _next; } 680 681 void set_on_work_list(bool c) { _on_work_list = c; } 682 bool is_on_work_list() const { return _on_work_list; } 683 684 bool has_pre_order() const { return _pre_order >= 0; } 685 void set_pre_order(int po) { assert(!has_pre_order(), ""); _pre_order = po; } 686 int pre_order() const { assert(has_pre_order(), ""); return _pre_order; } 687 void set_next_pre_order() { set_pre_order(outer()->inc_next_pre_order()); } 688 bool is_start() const { return _pre_order == outer()->start_block_num(); } 689 690 // Reverse post order 691 void df_init(); 692 bool has_post_order() const { return _post_order >= 0; } 693 void set_post_order(int po) { assert(!has_post_order() && po >= 0, ""); _post_order = po; } 694 void reset_post_order(int o){ _post_order = o; } 695 int post_order() const { assert(has_post_order(), ""); return _post_order; } 696 697 bool has_rpo() const { return has_post_order() && outer()->have_block_count(); } 698 int rpo() const { assert(has_rpo(), ""); return outer()->block_count() - post_order() - 1; } 699 void set_rpo_next(Block* b) { _rpo_next = b; } 700 Block* rpo_next() { return _rpo_next; } 701 702 // Loops 703 Loop* loop() const { return _loop; } 704 void set_loop(Loop* lp) { _loop = lp; } 705 bool is_loop_head() const { return _loop && _loop->head() == this; } 706 void set_irreducible_entry(bool c) { _irreducible_entry = c; } 707 bool is_irreducible_entry() const { return _irreducible_entry; } 708 void set_has_monitorenter() { _has_monitorenter = true; } 709 bool has_monitorenter() const { return _has_monitorenter; } 710 bool is_visited() const { return has_pre_order(); } 711 bool is_post_visited() const { return has_post_order(); } 712 bool is_clonable_exit(Loop* lp); 713 Block* looping_succ(Loop* lp); // Successor inside of loop 714 bool is_single_entry_loop_head() const { 715 if (!is_loop_head()) return false; 716 for (Loop* lp = loop(); lp != NULL && lp->head() == this; lp = lp->parent()) 717 if (lp->is_irreducible()) return false; 718 return true; 719 } 720 721 void print_value_on(outputStream* st) const PRODUCT_RETURN; 722 void print_on(outputStream* st) const PRODUCT_RETURN; 723 }; 724 725 // Loop 726 class Loop : public ResourceObj { 727 private: 728 Loop* _parent; 729 Loop* _sibling; // List of siblings, null terminated 730 Loop* _child; // Head of child list threaded thru sibling pointer 731 Block* _head; // Head of loop 732 Block* _tail; // Tail of loop 733 bool _irreducible; 734 LocalSet _def_locals; 735 736 public: 737 Loop(Block* head, Block* tail) : 738 _head(head), _tail(tail), 739 _parent(NULL), _sibling(NULL), _child(NULL), 740 _irreducible(false), _def_locals() {} 741 742 Loop* parent() const { return _parent; } 743 Loop* sibling() const { return _sibling; } 744 Loop* child() const { return _child; } 745 Block* head() const { return _head; } 746 Block* tail() const { return _tail; } 747 void set_parent(Loop* p) { _parent = p; } 748 void set_sibling(Loop* s) { _sibling = s; } 749 void set_child(Loop* c) { _child = c; } 750 void set_head(Block* hd) { _head = hd; } 751 void set_tail(Block* tl) { _tail = tl; } 752 753 int depth() const; // nesting depth 754 755 // Returns true if lp is a nested loop or us. 756 bool contains(Loop* lp) const; 757 bool contains(Block* blk) const { return contains(blk->loop()); } 758 759 // Data flow on locals 760 LocalSet* def_locals() { return &_def_locals; } 761 const LocalSet* def_locals() const { return &_def_locals; } 762 763 // Merge the branch lp into this branch, sorting on the loop head 764 // pre_orders. Returns the new branch. 765 Loop* sorted_merge(Loop* lp); 766 767 // Mark non-single entry to loop 768 void set_irreducible(Block* entry) { 769 _irreducible = true; 770 entry->set_irreducible_entry(true); 771 } 772 bool is_irreducible() const { return _irreducible; } 773 774 bool is_root() const { return _tail->pre_order() == max_jint; } 775 776 void print(outputStream* st = tty, int indent = 0) const PRODUCT_RETURN; 777 }; 778 779 // Postorder iteration over the loop tree. 780 class PostorderLoops : public StackObj { 781 private: 782 Loop* _root; 783 Loop* _current; 784 public: 785 PostorderLoops(Loop* root) : _root(root), _current(root) { 786 while (_current->child() != NULL) { 787 _current = _current->child(); 788 } 789 } 790 bool done() { return _current == NULL; } // Finished iterating? 791 void next(); // Advance to next loop 792 Loop* current() { return _current; } // Return current loop. 793 }; 794 795 // Preorder iteration over the loop tree. 796 class PreorderLoops : public StackObj { 797 private: 798 Loop* _root; 799 Loop* _current; 800 public: 801 PreorderLoops(Loop* root) : _root(root), _current(root) {} 802 bool done() { return _current == NULL; } // Finished iterating? 803 void next(); // Advance to next loop 804 Loop* current() { return _current; } // Return current loop. 805 }; 806 807 // Standard indexes of successors, for various bytecodes. 808 enum { 809 FALL_THROUGH = 0, // normal control 810 IF_NOT_TAKEN = 0, // the not-taken branch of an if (i.e., fall-through) 811 IF_TAKEN = 1, // the taken branch of an if 812 GOTO_TARGET = 0, // unique successor for goto, jsr, or ret 813 SWITCH_DEFAULT = 0, // default branch of a switch 814 SWITCH_CASES = 1 // first index for any non-default switch branches 815 // Unlike in other blocks, the successors of a switch are listed uniquely. 816 }; 817 818 private: 819 // A mapping from pre_order to Blocks. This array is created 820 // only at the end of the flow. 821 Block** _block_map; 822 823 // For each ciBlock index, a list of Blocks which share this ciBlock. 824 GrowableArray<Block*>** _idx_to_blocklist; 825 // count of ciBlocks 826 int _ciblock_count; 827 828 // Tells if a given instruction is able to generate an exception edge. 829 bool can_trap(ciBytecodeStream& str); 830 831 // Clone the loop heads. Returns true if any cloning occurred. 832 bool clone_loop_heads(Loop* lp, StateVector* temp_vector, JsrSet* temp_set); 833 834 // Clone lp's head and replace tail's successors with clone. 835 Block* clone_loop_head(Loop* lp, StateVector* temp_vector, JsrSet* temp_set); 836 837 public: 838 // Return the block beginning at bci which has a JsrSet compatible 839 // with jsrs. 840 Block* block_at(int bci, JsrSet* set, CreateOption option = create_public_copy); 841 842 // block factory 843 Block* get_block_for(int ciBlockIndex, JsrSet* jsrs, CreateOption option = create_public_copy); 844 845 // How many of the blocks have the backedge_copy bit set? 846 int backedge_copy_count(int ciBlockIndex, JsrSet* jsrs) const; 847 848 // Return an existing block containing bci which has a JsrSet compatible 849 // with jsrs, or NULL if there is none. 850 Block* existing_block_at(int bci, JsrSet* set) { return block_at(bci, set, no_create); } 851 852 // Tell whether the flow analysis has encountered an error of some sort. 853 bool failing() { return env()->failing() || _failure_reason != NULL; } 854 855 // Reason this compilation is failing, such as "too many basic blocks". 856 const char* failure_reason() { return _failure_reason; } 857 858 // Note a failure. 859 void record_failure(const char* reason); 860 861 // Return the block of a given pre-order number. 862 int have_block_count() const { return _block_map != NULL; } 863 int block_count() const { assert(have_block_count(), ""); 864 return _next_pre_order; } 865 Block* pre_order_at(int po) const { assert(0 <= po && po < block_count(), "out of bounds"); 866 return _block_map[po]; } 867 Block* start_block() const { return pre_order_at(start_block_num()); } 868 int start_block_num() const { return 0; } 869 Block* rpo_at(int rpo) const { assert(0 <= rpo && rpo < block_count(), "out of bounds"); 870 return _block_map[rpo]; } 871 int next_pre_order() { return _next_pre_order; } 872 int inc_next_pre_order() { return _next_pre_order++; } 873 874 private: 875 // A work list used during flow analysis. 876 Block* _work_list; 877 878 // List of blocks in reverse post order 879 Block* _rpo_list; 880 881 // Next Block::_pre_order. After mapping, doubles as block_count. 882 int _next_pre_order; 883 884 // Are there more blocks on the work list? 885 bool work_list_empty() { return _work_list == NULL; } 886 887 // Get the next basic block from our work list. 888 Block* work_list_next(); 889 890 // Add a basic block to our work list. 891 void add_to_work_list(Block* block); 892 893 // Prepend a basic block to rpo list. 894 void prepend_to_rpo_list(Block* blk) { 895 blk->set_rpo_next(_rpo_list); 896 _rpo_list = blk; 897 } 898 899 // Root of the loop tree 900 Loop* _loop_tree_root; 901 902 // State used for make_jsr_record 903 int _jsr_count; 904 GrowableArray<JsrRecord*>* _jsr_records; 905 906 public: 907 // Make a JsrRecord for a given (entry, return) pair, if such a record 908 // does not already exist. 909 JsrRecord* make_jsr_record(int entry_address, int return_address); 910 911 void set_loop_tree_root(Loop* ltr) { _loop_tree_root = ltr; } 912 Loop* loop_tree_root() { return _loop_tree_root; } 913 914 private: 915 // Get the initial state for start_bci: 916 const StateVector* get_start_state(); 917 918 // Merge the current state into all exceptional successors at the 919 // current point in the code. 920 void flow_exceptions(GrowableArray<Block*>* exceptions, 921 GrowableArray<ciInstanceKlass*>* exc_klasses, 922 StateVector* state); 923 924 // Merge the current state into all successors at the current point 925 // in the code. 926 void flow_successors(GrowableArray<Block*>* successors, 927 StateVector* state); 928 929 // Interpret the effects of the bytecodes on the incoming state 930 // vector of a basic block. Push the changed state to succeeding 931 // basic blocks. 932 void flow_block(Block* block, 933 StateVector* scratch_state, 934 JsrSet* scratch_jsrs); 935 936 // Perform the type flow analysis, creating and cloning Blocks as 937 // necessary. 938 void flow_types(); 939 940 // Perform the depth first type flow analysis. Helper for flow_types. 941 void df_flow_types(Block* start, 942 bool do_flow, 943 StateVector* temp_vector, 944 JsrSet* temp_set); 945 946 // Incrementally build loop tree. 947 void build_loop_tree(Block* blk); 948 949 // Create the block map, which indexes blocks in pre_order. 950 void map_blocks(); 951 952 public: 953 // Perform type inference flow analysis. 954 void do_flow(); 955 956 // Determine if bci is dominated by dom_bci 957 bool is_dominated_by(int bci, int dom_bci); 958 959 void print_on(outputStream* st) const PRODUCT_RETURN; 960 961 void rpo_print_on(outputStream* st) const PRODUCT_RETURN; 962 }; 963 964 #endif // SHARE_VM_CI_CITYPEFLOW_HPP