1 /* 2 * Copyright 2000-2009 Sun Microsystems, Inc. All Rights Reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 class BytecodeStream; 26 27 // The MethodData object collects counts and other profile information 28 // during zeroth-tier (interpretive) and first-tier execution. 29 // The profile is used later by compilation heuristics. Some heuristics 30 // enable use of aggressive (or "heroic") optimizations. An aggressive 31 // optimization often has a down-side, a corner case that it handles 32 // poorly, but which is thought to be rare. The profile provides 33 // evidence of this rarity for a given method or even BCI. It allows 34 // the compiler to back out of the optimization at places where it 35 // has historically been a poor choice. Other heuristics try to use 36 // specific information gathered about types observed at a given site. 37 // 38 // All data in the profile is approximate. It is expected to be accurate 39 // on the whole, but the system expects occasional inaccuraces, due to 40 // counter overflow, multiprocessor races during data collection, space 41 // limitations, missing MDO blocks, etc. Bad or missing data will degrade 42 // optimization quality but will not affect correctness. Also, each MDO 43 // is marked with its birth-date ("creation_mileage") which can be used 44 // to assess the quality ("maturity") of its data. 45 // 46 // Short (<32-bit) counters are designed to overflow to a known "saturated" 47 // state. Also, certain recorded per-BCI events are given one-bit counters 48 // which overflow to a saturated state which applied to all counters at 49 // that BCI. In other words, there is a small lattice which approximates 50 // the ideal of an infinite-precision counter for each event at each BCI, 51 // and the lattice quickly "bottoms out" in a state where all counters 52 // are taken to be indefinitely large. 53 // 54 // The reader will find many data races in profile gathering code, starting 55 // with invocation counter incrementation. None of these races harm correct 56 // execution of the compiled code. 57 58 // forward decl 59 class ProfileData; 60 61 // DataLayout 62 // 63 // Overlay for generic profiling data. 64 class DataLayout VALUE_OBJ_CLASS_SPEC { 65 private: 66 // Every data layout begins with a header. This header 67 // contains a tag, which is used to indicate the size/layout 68 // of the data, 4 bits of flags, which can be used in any way, 69 // 4 bits of trap history (none/one reason/many reasons), 70 // and a bci, which is used to tie this piece of data to a 71 // specific bci in the bytecodes. 72 union { 73 intptr_t _bits; 74 struct { 75 u1 _tag; 76 u1 _flags; 77 u2 _bci; 78 } _struct; 79 } _header; 80 81 // The data layout has an arbitrary number of cells, each sized 82 // to accomodate a pointer or an integer. 83 intptr_t _cells[1]; 84 85 // Some types of data layouts need a length field. 86 static bool needs_array_len(u1 tag); 87 88 public: 89 enum { 90 counter_increment = 1 91 }; 92 93 enum { 94 cell_size = sizeof(intptr_t) 95 }; 96 97 // Tag values 98 enum { 99 no_tag, 100 bit_data_tag, 101 counter_data_tag, 102 jump_data_tag, 103 receiver_type_data_tag, 104 virtual_call_data_tag, 105 ret_data_tag, 106 branch_data_tag, 107 multi_branch_data_tag, 108 arg_info_data_tag 109 }; 110 111 enum { 112 // The _struct._flags word is formatted as [trap_state:4 | flags:4]. 113 // The trap state breaks down further as [recompile:1 | reason:3]. 114 // This further breakdown is defined in deoptimization.cpp. 115 // See Deoptimization::trap_state_reason for an assert that 116 // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT. 117 // 118 // The trap_state is collected only if ProfileTraps is true. 119 trap_bits = 1+3, // 3: enough to distinguish [0..Reason_RECORDED_LIMIT]. 120 trap_shift = BitsPerByte - trap_bits, 121 trap_mask = right_n_bits(trap_bits), 122 trap_mask_in_place = (trap_mask << trap_shift), 123 flag_limit = trap_shift, 124 flag_mask = right_n_bits(flag_limit), 125 first_flag = 0 126 }; 127 128 // Size computation 129 static int header_size_in_bytes() { 130 return cell_size; 131 } 132 static int header_size_in_cells() { 133 return 1; 134 } 135 136 static int compute_size_in_bytes(int cell_count) { 137 return header_size_in_bytes() + cell_count * cell_size; 138 } 139 140 // Initialization 141 void initialize(u1 tag, u2 bci, int cell_count); 142 143 // Accessors 144 u1 tag() { 145 return _header._struct._tag; 146 } 147 148 // Return a few bits of trap state. Range is [0..trap_mask]. 149 // The state tells if traps with zero, one, or many reasons have occurred. 150 // It also tells whether zero or many recompilations have occurred. 151 // The associated trap histogram in the MDO itself tells whether 152 // traps are common or not. If a BCI shows that a trap X has 153 // occurred, and the MDO shows N occurrences of X, we make the 154 // simplifying assumption that all N occurrences can be blamed 155 // on that BCI. 156 int trap_state() { 157 return ((_header._struct._flags >> trap_shift) & trap_mask); 158 } 159 160 void set_trap_state(int new_state) { 161 assert(ProfileTraps, "used only under +ProfileTraps"); 162 uint old_flags = (_header._struct._flags & flag_mask); 163 _header._struct._flags = (new_state << trap_shift) | old_flags; 164 } 165 166 u1 flags() { 167 return _header._struct._flags; 168 } 169 170 u2 bci() { 171 return _header._struct._bci; 172 } 173 174 void set_header(intptr_t value) { 175 _header._bits = value; 176 } 177 void release_set_header(intptr_t value) { 178 OrderAccess::release_store_ptr(&_header._bits, value); 179 } 180 intptr_t header() { 181 return _header._bits; 182 } 183 void set_cell_at(int index, intptr_t value) { 184 _cells[index] = value; 185 } 186 void release_set_cell_at(int index, intptr_t value) { 187 OrderAccess::release_store_ptr(&_cells[index], value); 188 } 189 intptr_t cell_at(int index) { 190 return _cells[index]; 191 } 192 intptr_t* adr_cell_at(int index) { 193 return &_cells[index]; 194 } 195 oop* adr_oop_at(int index) { 196 return (oop*)&(_cells[index]); 197 } 198 199 void set_flag_at(int flag_number) { 200 assert(flag_number < flag_limit, "oob"); 201 _header._struct._flags |= (0x1 << flag_number); 202 } 203 bool flag_at(int flag_number) { 204 assert(flag_number < flag_limit, "oob"); 205 return (_header._struct._flags & (0x1 << flag_number)) != 0; 206 } 207 208 // Low-level support for code generation. 209 static ByteSize header_offset() { 210 return byte_offset_of(DataLayout, _header); 211 } 212 static ByteSize tag_offset() { 213 return byte_offset_of(DataLayout, _header._struct._tag); 214 } 215 static ByteSize flags_offset() { 216 return byte_offset_of(DataLayout, _header._struct._flags); 217 } 218 static ByteSize bci_offset() { 219 return byte_offset_of(DataLayout, _header._struct._bci); 220 } 221 static ByteSize cell_offset(int index) { 222 return byte_offset_of(DataLayout, _cells[index]); 223 } 224 // Return a value which, when or-ed as a byte into _flags, sets the flag. 225 static int flag_number_to_byte_constant(int flag_number) { 226 assert(0 <= flag_number && flag_number < flag_limit, "oob"); 227 DataLayout temp; temp.set_header(0); 228 temp.set_flag_at(flag_number); 229 return temp._header._struct._flags; 230 } 231 // Return a value which, when or-ed as a word into _header, sets the flag. 232 static intptr_t flag_mask_to_header_mask(int byte_constant) { 233 DataLayout temp; temp.set_header(0); 234 temp._header._struct._flags = byte_constant; 235 return temp._header._bits; 236 } 237 238 // GC support 239 ProfileData* data_in(); 240 void follow_weak_refs(BoolObjectClosure* cl); 241 }; 242 243 244 // ProfileData class hierarchy 245 class ProfileData; 246 class BitData; 247 class CounterData; 248 class ReceiverTypeData; 249 class VirtualCallData; 250 class RetData; 251 class JumpData; 252 class BranchData; 253 class ArrayData; 254 class MultiBranchData; 255 class ArgInfoData; 256 257 258 // ProfileData 259 // 260 // A ProfileData object is created to refer to a section of profiling 261 // data in a structured way. 262 class ProfileData : public ResourceObj { 263 private: 264 #ifndef PRODUCT 265 enum { 266 tab_width_one = 16, 267 tab_width_two = 36 268 }; 269 #endif // !PRODUCT 270 271 // This is a pointer to a section of profiling data. 272 DataLayout* _data; 273 274 protected: 275 DataLayout* data() { return _data; } 276 277 enum { 278 cell_size = DataLayout::cell_size 279 }; 280 281 public: 282 // How many cells are in this? 283 virtual int cell_count() { 284 ShouldNotReachHere(); 285 return -1; 286 } 287 288 // Return the size of this data. 289 int size_in_bytes() { 290 return DataLayout::compute_size_in_bytes(cell_count()); 291 } 292 293 protected: 294 // Low-level accessors for underlying data 295 void set_intptr_at(int index, intptr_t value) { 296 assert(0 <= index && index < cell_count(), "oob"); 297 data()->set_cell_at(index, value); 298 } 299 void release_set_intptr_at(int index, intptr_t value) { 300 assert(0 <= index && index < cell_count(), "oob"); 301 data()->release_set_cell_at(index, value); 302 } 303 intptr_t intptr_at(int index) { 304 assert(0 <= index && index < cell_count(), "oob"); 305 return data()->cell_at(index); 306 } 307 void set_uint_at(int index, uint value) { 308 set_intptr_at(index, (intptr_t) value); 309 } 310 void release_set_uint_at(int index, uint value) { 311 release_set_intptr_at(index, (intptr_t) value); 312 } 313 uint uint_at(int index) { 314 return (uint)intptr_at(index); 315 } 316 void set_int_at(int index, int value) { 317 set_intptr_at(index, (intptr_t) value); 318 } 319 void release_set_int_at(int index, int value) { 320 release_set_intptr_at(index, (intptr_t) value); 321 } 322 int int_at(int index) { 323 return (int)intptr_at(index); 324 } 325 int int_at_unchecked(int index) { 326 return (int)data()->cell_at(index); 327 } 328 void set_oop_at(int index, oop value) { 329 set_intptr_at(index, (intptr_t) value); 330 } 331 oop oop_at(int index) { 332 return (oop)intptr_at(index); 333 } 334 oop* adr_oop_at(int index) { 335 assert(0 <= index && index < cell_count(), "oob"); 336 return data()->adr_oop_at(index); 337 } 338 339 void set_flag_at(int flag_number) { 340 data()->set_flag_at(flag_number); 341 } 342 bool flag_at(int flag_number) { 343 return data()->flag_at(flag_number); 344 } 345 346 // two convenient imports for use by subclasses: 347 static ByteSize cell_offset(int index) { 348 return DataLayout::cell_offset(index); 349 } 350 static int flag_number_to_byte_constant(int flag_number) { 351 return DataLayout::flag_number_to_byte_constant(flag_number); 352 } 353 354 ProfileData(DataLayout* data) { 355 _data = data; 356 } 357 358 public: 359 // Constructor for invalid ProfileData. 360 ProfileData(); 361 362 u2 bci() { 363 return data()->bci(); 364 } 365 366 address dp() { 367 return (address)_data; 368 } 369 370 int trap_state() { 371 return data()->trap_state(); 372 } 373 void set_trap_state(int new_state) { 374 data()->set_trap_state(new_state); 375 } 376 377 // Type checking 378 virtual bool is_BitData() { return false; } 379 virtual bool is_CounterData() { return false; } 380 virtual bool is_JumpData() { return false; } 381 virtual bool is_ReceiverTypeData(){ return false; } 382 virtual bool is_VirtualCallData() { return false; } 383 virtual bool is_RetData() { return false; } 384 virtual bool is_BranchData() { return false; } 385 virtual bool is_ArrayData() { return false; } 386 virtual bool is_MultiBranchData() { return false; } 387 virtual bool is_ArgInfoData() { return false; } 388 389 390 BitData* as_BitData() { 391 assert(is_BitData(), "wrong type"); 392 return is_BitData() ? (BitData*) this : NULL; 393 } 394 CounterData* as_CounterData() { 395 assert(is_CounterData(), "wrong type"); 396 return is_CounterData() ? (CounterData*) this : NULL; 397 } 398 JumpData* as_JumpData() { 399 assert(is_JumpData(), "wrong type"); 400 return is_JumpData() ? (JumpData*) this : NULL; 401 } 402 ReceiverTypeData* as_ReceiverTypeData() { 403 assert(is_ReceiverTypeData(), "wrong type"); 404 return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL; 405 } 406 VirtualCallData* as_VirtualCallData() { 407 assert(is_VirtualCallData(), "wrong type"); 408 return is_VirtualCallData() ? (VirtualCallData*)this : NULL; 409 } 410 RetData* as_RetData() { 411 assert(is_RetData(), "wrong type"); 412 return is_RetData() ? (RetData*) this : NULL; 413 } 414 BranchData* as_BranchData() { 415 assert(is_BranchData(), "wrong type"); 416 return is_BranchData() ? (BranchData*) this : NULL; 417 } 418 ArrayData* as_ArrayData() { 419 assert(is_ArrayData(), "wrong type"); 420 return is_ArrayData() ? (ArrayData*) this : NULL; 421 } 422 MultiBranchData* as_MultiBranchData() { 423 assert(is_MultiBranchData(), "wrong type"); 424 return is_MultiBranchData() ? (MultiBranchData*)this : NULL; 425 } 426 ArgInfoData* as_ArgInfoData() { 427 assert(is_ArgInfoData(), "wrong type"); 428 return is_ArgInfoData() ? (ArgInfoData*)this : NULL; 429 } 430 431 432 // Subclass specific initialization 433 virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {} 434 435 // GC support 436 virtual void follow_contents() {} 437 virtual void oop_iterate(OopClosure* blk) {} 438 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {} 439 virtual void adjust_pointers() {} 440 virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure) {} 441 442 #ifndef SERIALGC 443 // Parallel old support 444 virtual void follow_contents(ParCompactionManager* cm) {} 445 virtual void update_pointers() {} 446 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr) {} 447 #endif // SERIALGC 448 449 // CI translation: ProfileData can represent both MethodDataOop data 450 // as well as CIMethodData data. This function is provided for translating 451 // an oop in a ProfileData to the ci equivalent. Generally speaking, 452 // most ProfileData don't require any translation, so we provide the null 453 // translation here, and the required translators are in the ci subclasses. 454 virtual void translate_from(ProfileData* data) {} 455 456 virtual void print_data_on(outputStream* st) { 457 ShouldNotReachHere(); 458 } 459 460 #ifndef PRODUCT 461 void print_shared(outputStream* st, const char* name); 462 void tab(outputStream* st); 463 #endif 464 }; 465 466 // BitData 467 // 468 // A BitData holds a flag or two in its header. 469 class BitData : public ProfileData { 470 protected: 471 enum { 472 // null_seen: 473 // saw a null operand (cast/aastore/instanceof) 474 null_seen_flag = DataLayout::first_flag + 0 475 }; 476 enum { bit_cell_count = 0 }; // no additional data fields needed. 477 public: 478 BitData(DataLayout* layout) : ProfileData(layout) { 479 } 480 481 virtual bool is_BitData() { return true; } 482 483 static int static_cell_count() { 484 return bit_cell_count; 485 } 486 487 virtual int cell_count() { 488 return static_cell_count(); 489 } 490 491 // Accessor 492 493 // The null_seen flag bit is specially known to the interpreter. 494 // Consulting it allows the compiler to avoid setting up null_check traps. 495 bool null_seen() { return flag_at(null_seen_flag); } 496 void set_null_seen() { set_flag_at(null_seen_flag); } 497 498 499 // Code generation support 500 static int null_seen_byte_constant() { 501 return flag_number_to_byte_constant(null_seen_flag); 502 } 503 504 static ByteSize bit_data_size() { 505 return cell_offset(bit_cell_count); 506 } 507 508 #ifndef PRODUCT 509 void print_data_on(outputStream* st); 510 #endif 511 }; 512 513 // CounterData 514 // 515 // A CounterData corresponds to a simple counter. 516 class CounterData : public BitData { 517 protected: 518 enum { 519 count_off, 520 counter_cell_count 521 }; 522 public: 523 CounterData(DataLayout* layout) : BitData(layout) {} 524 525 virtual bool is_CounterData() { return true; } 526 527 static int static_cell_count() { 528 return counter_cell_count; 529 } 530 531 virtual int cell_count() { 532 return static_cell_count(); 533 } 534 535 // Direct accessor 536 uint count() { 537 return uint_at(count_off); 538 } 539 540 // Code generation support 541 static ByteSize count_offset() { 542 return cell_offset(count_off); 543 } 544 static ByteSize counter_data_size() { 545 return cell_offset(counter_cell_count); 546 } 547 548 void set_count(uint count) { 549 set_uint_at(count_off, count); 550 } 551 552 #ifndef PRODUCT 553 void print_data_on(outputStream* st); 554 #endif 555 }; 556 557 // JumpData 558 // 559 // A JumpData is used to access profiling information for a direct 560 // branch. It is a counter, used for counting the number of branches, 561 // plus a data displacement, used for realigning the data pointer to 562 // the corresponding target bci. 563 class JumpData : public ProfileData { 564 protected: 565 enum { 566 taken_off_set, 567 displacement_off_set, 568 jump_cell_count 569 }; 570 571 void set_displacement(int displacement) { 572 set_int_at(displacement_off_set, displacement); 573 } 574 575 public: 576 JumpData(DataLayout* layout) : ProfileData(layout) { 577 assert(layout->tag() == DataLayout::jump_data_tag || 578 layout->tag() == DataLayout::branch_data_tag, "wrong type"); 579 } 580 581 virtual bool is_JumpData() { return true; } 582 583 static int static_cell_count() { 584 return jump_cell_count; 585 } 586 587 virtual int cell_count() { 588 return static_cell_count(); 589 } 590 591 // Direct accessor 592 uint taken() { 593 return uint_at(taken_off_set); 594 } 595 // Saturating counter 596 uint inc_taken() { 597 uint cnt = taken() + 1; 598 // Did we wrap? Will compiler screw us?? 599 if (cnt == 0) cnt--; 600 set_uint_at(taken_off_set, cnt); 601 return cnt; 602 } 603 604 int displacement() { 605 return int_at(displacement_off_set); 606 } 607 608 // Code generation support 609 static ByteSize taken_offset() { 610 return cell_offset(taken_off_set); 611 } 612 613 static ByteSize displacement_offset() { 614 return cell_offset(displacement_off_set); 615 } 616 617 // Specific initialization. 618 void post_initialize(BytecodeStream* stream, methodDataOop mdo); 619 620 #ifndef PRODUCT 621 void print_data_on(outputStream* st); 622 #endif 623 }; 624 625 // ReceiverTypeData 626 // 627 // A ReceiverTypeData is used to access profiling information about a 628 // dynamic type check. It consists of a counter which counts the total times 629 // that the check is reached, and a series of (klassOop, count) pairs 630 // which are used to store a type profile for the receiver of the check. 631 class ReceiverTypeData : public CounterData { 632 protected: 633 enum { 634 receiver0_offset = counter_cell_count, 635 count0_offset, 636 receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset 637 }; 638 639 public: 640 ReceiverTypeData(DataLayout* layout) : CounterData(layout) { 641 assert(layout->tag() == DataLayout::receiver_type_data_tag || 642 layout->tag() == DataLayout::virtual_call_data_tag, "wrong type"); 643 } 644 645 virtual bool is_ReceiverTypeData() { return true; } 646 647 static int static_cell_count() { 648 return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count; 649 } 650 651 virtual int cell_count() { 652 return static_cell_count(); 653 } 654 655 // Direct accessors 656 static uint row_limit() { 657 return TypeProfileWidth; 658 } 659 static int receiver_cell_index(uint row) { 660 return receiver0_offset + row * receiver_type_row_cell_count; 661 } 662 static int receiver_count_cell_index(uint row) { 663 return count0_offset + row * receiver_type_row_cell_count; 664 } 665 666 // Get the receiver at row. The 'unchecked' version is needed by parallel old 667 // gc; it does not assert the receiver is a klass. During compaction of the 668 // perm gen, the klass may already have moved, so the is_klass() predicate 669 // would fail. The 'normal' version should be used whenever possible. 670 klassOop receiver_unchecked(uint row) { 671 assert(row < row_limit(), "oob"); 672 oop recv = oop_at(receiver_cell_index(row)); 673 return (klassOop)recv; 674 } 675 676 klassOop receiver(uint row) { 677 klassOop recv = receiver_unchecked(row); 678 assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type"); 679 return recv; 680 } 681 682 void set_receiver(uint row, oop p) { 683 assert((uint)row < row_limit(), "oob"); 684 set_oop_at(receiver_cell_index(row), p); 685 } 686 687 uint receiver_count(uint row) { 688 assert(row < row_limit(), "oob"); 689 return uint_at(receiver_count_cell_index(row)); 690 } 691 692 void set_receiver_count(uint row, uint count) { 693 assert(row < row_limit(), "oob"); 694 set_uint_at(receiver_count_cell_index(row), count); 695 } 696 697 void clear_row(uint row) { 698 assert(row < row_limit(), "oob"); 699 // Cleare total count - indicator of polimorphic call site. 700 // An additional receiver will be recorded in the cleaned row 701 // during next call execution. 702 set_count(0); 703 set_receiver(row, NULL); 704 set_receiver_count(row, 0); 705 } 706 707 // Code generation support 708 static ByteSize receiver_offset(uint row) { 709 return cell_offset(receiver_cell_index(row)); 710 } 711 static ByteSize receiver_count_offset(uint row) { 712 return cell_offset(receiver_count_cell_index(row)); 713 } 714 static ByteSize receiver_type_data_size() { 715 return cell_offset(static_cell_count()); 716 } 717 718 // GC support 719 virtual void follow_contents(); 720 virtual void oop_iterate(OopClosure* blk); 721 virtual void oop_iterate_m(OopClosure* blk, MemRegion mr); 722 virtual void adjust_pointers(); 723 virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure); 724 725 #ifndef SERIALGC 726 // Parallel old support 727 virtual void follow_contents(ParCompactionManager* cm); 728 virtual void update_pointers(); 729 virtual void update_pointers(HeapWord* beg_addr, HeapWord* end_addr); 730 #endif // SERIALGC 731 732 oop* adr_receiver(uint row) { 733 return adr_oop_at(receiver_cell_index(row)); 734 } 735 736 #ifndef PRODUCT 737 void print_receiver_data_on(outputStream* st); 738 void print_data_on(outputStream* st); 739 #endif 740 }; 741 742 // VirtualCallData 743 // 744 // A VirtualCallData is used to access profiling information about a 745 // virtual call. For now, it has nothing more than a ReceiverTypeData. 746 class VirtualCallData : public ReceiverTypeData { 747 public: 748 VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) { 749 assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type"); 750 } 751 752 virtual bool is_VirtualCallData() { return true; } 753 754 static int static_cell_count() { 755 // At this point we could add more profile state, e.g., for arguments. 756 // But for now it's the same size as the base record type. 757 return ReceiverTypeData::static_cell_count(); 758 } 759 760 virtual int cell_count() { 761 return static_cell_count(); 762 } 763 764 // Direct accessors 765 static ByteSize virtual_call_data_size() { 766 return cell_offset(static_cell_count()); 767 } 768 769 #ifndef PRODUCT 770 void print_data_on(outputStream* st); 771 #endif 772 }; 773 774 // RetData 775 // 776 // A RetData is used to access profiling information for a ret bytecode. 777 // It is composed of a count of the number of times that the ret has 778 // been executed, followed by a series of triples of the form 779 // (bci, count, di) which count the number of times that some bci was the 780 // target of the ret and cache a corresponding data displacement. 781 class RetData : public CounterData { 782 protected: 783 enum { 784 bci0_offset = counter_cell_count, 785 count0_offset, 786 displacement0_offset, 787 ret_row_cell_count = (displacement0_offset + 1) - bci0_offset 788 }; 789 790 void set_bci(uint row, int bci) { 791 assert((uint)row < row_limit(), "oob"); 792 set_int_at(bci0_offset + row * ret_row_cell_count, bci); 793 } 794 void release_set_bci(uint row, int bci) { 795 assert((uint)row < row_limit(), "oob"); 796 // 'release' when setting the bci acts as a valid flag for other 797 // threads wrt bci_count and bci_displacement. 798 release_set_int_at(bci0_offset + row * ret_row_cell_count, bci); 799 } 800 void set_bci_count(uint row, uint count) { 801 assert((uint)row < row_limit(), "oob"); 802 set_uint_at(count0_offset + row * ret_row_cell_count, count); 803 } 804 void set_bci_displacement(uint row, int disp) { 805 set_int_at(displacement0_offset + row * ret_row_cell_count, disp); 806 } 807 808 public: 809 RetData(DataLayout* layout) : CounterData(layout) { 810 assert(layout->tag() == DataLayout::ret_data_tag, "wrong type"); 811 } 812 813 virtual bool is_RetData() { return true; } 814 815 enum { 816 no_bci = -1 // value of bci when bci1/2 are not in use. 817 }; 818 819 static int static_cell_count() { 820 return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count; 821 } 822 823 virtual int cell_count() { 824 return static_cell_count(); 825 } 826 827 static uint row_limit() { 828 return BciProfileWidth; 829 } 830 static int bci_cell_index(uint row) { 831 return bci0_offset + row * ret_row_cell_count; 832 } 833 static int bci_count_cell_index(uint row) { 834 return count0_offset + row * ret_row_cell_count; 835 } 836 static int bci_displacement_cell_index(uint row) { 837 return displacement0_offset + row * ret_row_cell_count; 838 } 839 840 // Direct accessors 841 int bci(uint row) { 842 return int_at(bci_cell_index(row)); 843 } 844 uint bci_count(uint row) { 845 return uint_at(bci_count_cell_index(row)); 846 } 847 int bci_displacement(uint row) { 848 return int_at(bci_displacement_cell_index(row)); 849 } 850 851 // Interpreter Runtime support 852 address fixup_ret(int return_bci, methodDataHandle mdo); 853 854 // Code generation support 855 static ByteSize bci_offset(uint row) { 856 return cell_offset(bci_cell_index(row)); 857 } 858 static ByteSize bci_count_offset(uint row) { 859 return cell_offset(bci_count_cell_index(row)); 860 } 861 static ByteSize bci_displacement_offset(uint row) { 862 return cell_offset(bci_displacement_cell_index(row)); 863 } 864 865 // Specific initialization. 866 void post_initialize(BytecodeStream* stream, methodDataOop mdo); 867 868 #ifndef PRODUCT 869 void print_data_on(outputStream* st); 870 #endif 871 }; 872 873 // BranchData 874 // 875 // A BranchData is used to access profiling data for a two-way branch. 876 // It consists of taken and not_taken counts as well as a data displacement 877 // for the taken case. 878 class BranchData : public JumpData { 879 protected: 880 enum { 881 not_taken_off_set = jump_cell_count, 882 branch_cell_count 883 }; 884 885 void set_displacement(int displacement) { 886 set_int_at(displacement_off_set, displacement); 887 } 888 889 public: 890 BranchData(DataLayout* layout) : JumpData(layout) { 891 assert(layout->tag() == DataLayout::branch_data_tag, "wrong type"); 892 } 893 894 virtual bool is_BranchData() { return true; } 895 896 static int static_cell_count() { 897 return branch_cell_count; 898 } 899 900 virtual int cell_count() { 901 return static_cell_count(); 902 } 903 904 // Direct accessor 905 uint not_taken() { 906 return uint_at(not_taken_off_set); 907 } 908 909 uint inc_not_taken() { 910 uint cnt = not_taken() + 1; 911 // Did we wrap? Will compiler screw us?? 912 if (cnt == 0) cnt--; 913 set_uint_at(not_taken_off_set, cnt); 914 return cnt; 915 } 916 917 // Code generation support 918 static ByteSize not_taken_offset() { 919 return cell_offset(not_taken_off_set); 920 } 921 static ByteSize branch_data_size() { 922 return cell_offset(branch_cell_count); 923 } 924 925 // Specific initialization. 926 void post_initialize(BytecodeStream* stream, methodDataOop mdo); 927 928 #ifndef PRODUCT 929 void print_data_on(outputStream* st); 930 #endif 931 }; 932 933 // ArrayData 934 // 935 // A ArrayData is a base class for accessing profiling data which does 936 // not have a statically known size. It consists of an array length 937 // and an array start. 938 class ArrayData : public ProfileData { 939 protected: 940 friend class DataLayout; 941 942 enum { 943 array_len_off_set, 944 array_start_off_set 945 }; 946 947 uint array_uint_at(int index) { 948 int aindex = index + array_start_off_set; 949 return uint_at(aindex); 950 } 951 int array_int_at(int index) { 952 int aindex = index + array_start_off_set; 953 return int_at(aindex); 954 } 955 oop array_oop_at(int index) { 956 int aindex = index + array_start_off_set; 957 return oop_at(aindex); 958 } 959 void array_set_int_at(int index, int value) { 960 int aindex = index + array_start_off_set; 961 set_int_at(aindex, value); 962 } 963 964 // Code generation support for subclasses. 965 static ByteSize array_element_offset(int index) { 966 return cell_offset(array_start_off_set + index); 967 } 968 969 public: 970 ArrayData(DataLayout* layout) : ProfileData(layout) {} 971 972 virtual bool is_ArrayData() { return true; } 973 974 static int static_cell_count() { 975 return -1; 976 } 977 978 int array_len() { 979 return int_at_unchecked(array_len_off_set); 980 } 981 982 virtual int cell_count() { 983 return array_len() + 1; 984 } 985 986 // Code generation support 987 static ByteSize array_len_offset() { 988 return cell_offset(array_len_off_set); 989 } 990 static ByteSize array_start_offset() { 991 return cell_offset(array_start_off_set); 992 } 993 }; 994 995 // MultiBranchData 996 // 997 // A MultiBranchData is used to access profiling information for 998 // a multi-way branch (*switch bytecodes). It consists of a series 999 // of (count, displacement) pairs, which count the number of times each 1000 // case was taken and specify the data displacment for each branch target. 1001 class MultiBranchData : public ArrayData { 1002 protected: 1003 enum { 1004 default_count_off_set, 1005 default_disaplacement_off_set, 1006 case_array_start 1007 }; 1008 enum { 1009 relative_count_off_set, 1010 relative_displacement_off_set, 1011 per_case_cell_count 1012 }; 1013 1014 void set_default_displacement(int displacement) { 1015 array_set_int_at(default_disaplacement_off_set, displacement); 1016 } 1017 void set_displacement_at(int index, int displacement) { 1018 array_set_int_at(case_array_start + 1019 index * per_case_cell_count + 1020 relative_displacement_off_set, 1021 displacement); 1022 } 1023 1024 public: 1025 MultiBranchData(DataLayout* layout) : ArrayData(layout) { 1026 assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type"); 1027 } 1028 1029 virtual bool is_MultiBranchData() { return true; } 1030 1031 static int compute_cell_count(BytecodeStream* stream); 1032 1033 int number_of_cases() { 1034 int alen = array_len() - 2; // get rid of default case here. 1035 assert(alen % per_case_cell_count == 0, "must be even"); 1036 return (alen / per_case_cell_count); 1037 } 1038 1039 uint default_count() { 1040 return array_uint_at(default_count_off_set); 1041 } 1042 int default_displacement() { 1043 return array_int_at(default_disaplacement_off_set); 1044 } 1045 1046 uint count_at(int index) { 1047 return array_uint_at(case_array_start + 1048 index * per_case_cell_count + 1049 relative_count_off_set); 1050 } 1051 int displacement_at(int index) { 1052 return array_int_at(case_array_start + 1053 index * per_case_cell_count + 1054 relative_displacement_off_set); 1055 } 1056 1057 // Code generation support 1058 static ByteSize default_count_offset() { 1059 return array_element_offset(default_count_off_set); 1060 } 1061 static ByteSize default_displacement_offset() { 1062 return array_element_offset(default_disaplacement_off_set); 1063 } 1064 static ByteSize case_count_offset(int index) { 1065 return case_array_offset() + 1066 (per_case_size() * index) + 1067 relative_count_offset(); 1068 } 1069 static ByteSize case_array_offset() { 1070 return array_element_offset(case_array_start); 1071 } 1072 static ByteSize per_case_size() { 1073 return in_ByteSize(per_case_cell_count) * cell_size; 1074 } 1075 static ByteSize relative_count_offset() { 1076 return in_ByteSize(relative_count_off_set) * cell_size; 1077 } 1078 static ByteSize relative_displacement_offset() { 1079 return in_ByteSize(relative_displacement_off_set) * cell_size; 1080 } 1081 1082 // Specific initialization. 1083 void post_initialize(BytecodeStream* stream, methodDataOop mdo); 1084 1085 #ifndef PRODUCT 1086 void print_data_on(outputStream* st); 1087 #endif 1088 }; 1089 1090 class ArgInfoData : public ArrayData { 1091 1092 public: 1093 ArgInfoData(DataLayout* layout) : ArrayData(layout) { 1094 assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type"); 1095 } 1096 1097 virtual bool is_ArgInfoData() { return true; } 1098 1099 1100 int number_of_args() { 1101 return array_len(); 1102 } 1103 1104 uint arg_modified(int arg) { 1105 return array_uint_at(arg); 1106 } 1107 1108 void set_arg_modified(int arg, uint val) { 1109 array_set_int_at(arg, val); 1110 } 1111 1112 #ifndef PRODUCT 1113 void print_data_on(outputStream* st); 1114 #endif 1115 }; 1116 1117 // methodDataOop 1118 // 1119 // A methodDataOop holds information which has been collected about 1120 // a method. Its layout looks like this: 1121 // 1122 // ----------------------------- 1123 // | header | 1124 // | klass | 1125 // ----------------------------- 1126 // | method | 1127 // | size of the methodDataOop | 1128 // ----------------------------- 1129 // | Data entries... | 1130 // | (variable size) | 1131 // | | 1132 // . . 1133 // . . 1134 // . . 1135 // | | 1136 // ----------------------------- 1137 // 1138 // The data entry area is a heterogeneous array of DataLayouts. Each 1139 // DataLayout in the array corresponds to a specific bytecode in the 1140 // method. The entries in the array are sorted by the corresponding 1141 // bytecode. Access to the data is via resource-allocated ProfileData, 1142 // which point to the underlying blocks of DataLayout structures. 1143 // 1144 // During interpretation, if profiling in enabled, the interpreter 1145 // maintains a method data pointer (mdp), which points at the entry 1146 // in the array corresponding to the current bci. In the course of 1147 // intepretation, when a bytecode is encountered that has profile data 1148 // associated with it, the entry pointed to by mdp is updated, then the 1149 // mdp is adjusted to point to the next appropriate DataLayout. If mdp 1150 // is NULL to begin with, the interpreter assumes that the current method 1151 // is not (yet) being profiled. 1152 // 1153 // In methodDataOop parlance, "dp" is a "data pointer", the actual address 1154 // of a DataLayout element. A "di" is a "data index", the offset in bytes 1155 // from the base of the data entry array. A "displacement" is the byte offset 1156 // in certain ProfileData objects that indicate the amount the mdp must be 1157 // adjusted in the event of a change in control flow. 1158 // 1159 1160 class methodDataOopDesc : public oopDesc { 1161 friend class VMStructs; 1162 private: 1163 friend class ProfileData; 1164 1165 // Back pointer to the methodOop 1166 methodOop _method; 1167 1168 // Size of this oop in bytes 1169 int _size; 1170 1171 // Cached hint for bci_to_dp and bci_to_data 1172 int _hint_di; 1173 1174 // Whole-method sticky bits and flags 1175 public: 1176 enum { 1177 _trap_hist_limit = 16, // decoupled from Deoptimization::Reason_LIMIT 1178 _trap_hist_mask = max_jubyte, 1179 _extra_data_count = 4 // extra DataLayout headers, for trap history 1180 }; // Public flag values 1181 private: 1182 uint _nof_decompiles; // count of all nmethod removals 1183 uint _nof_overflow_recompiles; // recompile count, excluding recomp. bits 1184 uint _nof_overflow_traps; // trap count, excluding _trap_hist 1185 union { 1186 intptr_t _align; 1187 u1 _array[_trap_hist_limit]; 1188 } _trap_hist; 1189 1190 // Support for interprocedural escape analysis, from Thomas Kotzmann. 1191 intx _eflags; // flags on escape information 1192 intx _arg_local; // bit set of non-escaping arguments 1193 intx _arg_stack; // bit set of stack-allocatable arguments 1194 intx _arg_returned; // bit set of returned arguments 1195 1196 int _creation_mileage; // method mileage at MDO creation 1197 1198 // Size of _data array in bytes. (Excludes header and extra_data fields.) 1199 int _data_size; 1200 1201 // Beginning of the data entries 1202 intptr_t _data[1]; 1203 1204 // Helper for size computation 1205 static int compute_data_size(BytecodeStream* stream); 1206 static int bytecode_cell_count(Bytecodes::Code code); 1207 enum { no_profile_data = -1, variable_cell_count = -2 }; 1208 1209 // Helper for initialization 1210 DataLayout* data_layout_at(int data_index) { 1211 assert(data_index % sizeof(intptr_t) == 0, "unaligned"); 1212 return (DataLayout*) (((address)_data) + data_index); 1213 } 1214 1215 // Initialize an individual data segment. Returns the size of 1216 // the segment in bytes. 1217 int initialize_data(BytecodeStream* stream, int data_index); 1218 1219 // Helper for data_at 1220 DataLayout* limit_data_position() { 1221 return (DataLayout*)((address)data_base() + _data_size); 1222 } 1223 bool out_of_bounds(int data_index) { 1224 return data_index >= data_size(); 1225 } 1226 1227 // Give each of the data entries a chance to perform specific 1228 // data initialization. 1229 void post_initialize(BytecodeStream* stream); 1230 1231 // hint accessors 1232 int hint_di() const { return _hint_di; } 1233 void set_hint_di(int di) { 1234 assert(!out_of_bounds(di), "hint_di out of bounds"); 1235 _hint_di = di; 1236 } 1237 ProfileData* data_before(int bci) { 1238 // avoid SEGV on this edge case 1239 if (data_size() == 0) 1240 return NULL; 1241 int hint = hint_di(); 1242 if (data_layout_at(hint)->bci() <= bci) 1243 return data_at(hint); 1244 return first_data(); 1245 } 1246 1247 // What is the index of the first data entry? 1248 int first_di() { return 0; } 1249 1250 // Find or create an extra ProfileData: 1251 ProfileData* bci_to_extra_data(int bci, bool create_if_missing); 1252 1253 // return the argument info cell 1254 ArgInfoData *arg_info(); 1255 1256 public: 1257 static int header_size() { 1258 return sizeof(methodDataOopDesc)/wordSize; 1259 } 1260 1261 // Compute the size of a methodDataOop before it is created. 1262 static int compute_allocation_size_in_bytes(methodHandle method); 1263 static int compute_allocation_size_in_words(methodHandle method); 1264 static int compute_extra_data_count(int data_size, int empty_bc_count); 1265 1266 // Determine if a given bytecode can have profile information. 1267 static bool bytecode_has_profile(Bytecodes::Code code) { 1268 return bytecode_cell_count(code) != no_profile_data; 1269 } 1270 1271 // Perform initialization of a new methodDataOop 1272 void initialize(methodHandle method); 1273 1274 // My size 1275 int object_size_in_bytes() { return _size; } 1276 int object_size() { 1277 return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord); 1278 } 1279 1280 int creation_mileage() const { return _creation_mileage; } 1281 void set_creation_mileage(int x) { _creation_mileage = x; } 1282 bool is_mature() const; // consult mileage and ProfileMaturityPercentage 1283 static int mileage_of(methodOop m); 1284 1285 // Support for interprocedural escape analysis, from Thomas Kotzmann. 1286 enum EscapeFlag { 1287 estimated = 1 << 0, 1288 return_local = 1 << 1, 1289 return_allocated = 1 << 2, 1290 allocated_escapes = 1 << 3, 1291 unknown_modified = 1 << 4 1292 }; 1293 1294 intx eflags() { return _eflags; } 1295 intx arg_local() { return _arg_local; } 1296 intx arg_stack() { return _arg_stack; } 1297 intx arg_returned() { return _arg_returned; } 1298 uint arg_modified(int a) { ArgInfoData *aid = arg_info(); 1299 assert(a >= 0 && a < aid->number_of_args(), "valid argument number"); 1300 return aid->arg_modified(a); } 1301 1302 void set_eflags(intx v) { _eflags = v; } 1303 void set_arg_local(intx v) { _arg_local = v; } 1304 void set_arg_stack(intx v) { _arg_stack = v; } 1305 void set_arg_returned(intx v) { _arg_returned = v; } 1306 void set_arg_modified(int a, uint v) { ArgInfoData *aid = arg_info(); 1307 assert(a >= 0 && a < aid->number_of_args(), "valid argument number"); 1308 1309 aid->set_arg_modified(a, v); } 1310 1311 void clear_escape_info() { _eflags = _arg_local = _arg_stack = _arg_returned = 0; } 1312 1313 // Location and size of data area 1314 address data_base() const { 1315 return (address) _data; 1316 } 1317 int data_size() { 1318 return _data_size; 1319 } 1320 1321 // Accessors 1322 methodOop method() { return _method; } 1323 1324 // Get the data at an arbitrary (sort of) data index. 1325 ProfileData* data_at(int data_index); 1326 1327 // Walk through the data in order. 1328 ProfileData* first_data() { return data_at(first_di()); } 1329 ProfileData* next_data(ProfileData* current); 1330 bool is_valid(ProfileData* current) { return current != NULL; } 1331 1332 // Convert a dp (data pointer) to a di (data index). 1333 int dp_to_di(address dp) { 1334 return dp - ((address)_data); 1335 } 1336 1337 address di_to_dp(int di) { 1338 return (address)data_layout_at(di); 1339 } 1340 1341 // bci to di/dp conversion. 1342 address bci_to_dp(int bci); 1343 int bci_to_di(int bci) { 1344 return dp_to_di(bci_to_dp(bci)); 1345 } 1346 1347 // Get the data at an arbitrary bci, or NULL if there is none. 1348 ProfileData* bci_to_data(int bci); 1349 1350 // Same, but try to create an extra_data record if one is needed: 1351 ProfileData* allocate_bci_to_data(int bci) { 1352 ProfileData* data = bci_to_data(bci); 1353 return (data != NULL) ? data : bci_to_extra_data(bci, true); 1354 } 1355 1356 // Add a handful of extra data records, for trap tracking. 1357 DataLayout* extra_data_base() { return limit_data_position(); } 1358 DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); } 1359 int extra_data_size() { return (address)extra_data_limit() 1360 - (address)extra_data_base(); } 1361 static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); } 1362 1363 // Return (uint)-1 for overflow. 1364 uint trap_count(int reason) const { 1365 assert((uint)reason < _trap_hist_limit, "oob"); 1366 return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1; 1367 } 1368 // For loops: 1369 static uint trap_reason_limit() { return _trap_hist_limit; } 1370 static uint trap_count_limit() { return _trap_hist_mask; } 1371 uint inc_trap_count(int reason) { 1372 // Count another trap, anywhere in this method. 1373 assert(reason >= 0, "must be single trap"); 1374 if ((uint)reason < _trap_hist_limit) { 1375 uint cnt1 = 1 + _trap_hist._array[reason]; 1376 if ((cnt1 & _trap_hist_mask) != 0) { // if no counter overflow... 1377 _trap_hist._array[reason] = cnt1; 1378 return cnt1; 1379 } else { 1380 return _trap_hist_mask + (++_nof_overflow_traps); 1381 } 1382 } else { 1383 // Could not represent the count in the histogram. 1384 return (++_nof_overflow_traps); 1385 } 1386 } 1387 1388 uint overflow_trap_count() const { 1389 return _nof_overflow_traps; 1390 } 1391 uint overflow_recompile_count() const { 1392 return _nof_overflow_recompiles; 1393 } 1394 void inc_overflow_recompile_count() { 1395 _nof_overflow_recompiles += 1; 1396 } 1397 uint decompile_count() const { 1398 return _nof_decompiles; 1399 } 1400 void inc_decompile_count() { 1401 _nof_decompiles += 1; 1402 if (decompile_count() > (uint)PerMethodRecompilationCutoff) { 1403 method()->set_not_compilable(); 1404 } 1405 } 1406 1407 // Support for code generation 1408 static ByteSize data_offset() { 1409 return byte_offset_of(methodDataOopDesc, _data[0]); 1410 } 1411 1412 // GC support 1413 oop* adr_method() const { return (oop*)&_method; } 1414 bool object_is_parsable() const { return _size != 0; } 1415 void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; } 1416 1417 #ifndef PRODUCT 1418 // printing support for method data 1419 void print_data_on(outputStream* st); 1420 #endif 1421 1422 // verification 1423 void verify_data_on(outputStream* st); 1424 };