1 /*
   2  * Copyright (c) 2000, 2011, 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  *
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
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  20  * or visit www.oracle.com if you need additional information or have any
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  24 
  25 #ifndef SHARE_VM_OOPS_METHODDATAOOP_HPP
  26 #define SHARE_VM_OOPS_METHODDATAOOP_HPP
  27 
  28 #include "interpreter/bytecodes.hpp"
  29 #include "memory/universe.hpp"
  30 #include "oops/methodOop.hpp"
  31 #include "oops/oop.hpp"
  32 #include "runtime/orderAccess.hpp"
  33 
  34 class BytecodeStream;
  35 
  36 // The MethodData object collects counts and other profile information
  37 // during zeroth-tier (interpretive) and first-tier execution.
  38 // The profile is used later by compilation heuristics.  Some heuristics
  39 // enable use of aggressive (or "heroic") optimizations.  An aggressive
  40 // optimization often has a down-side, a corner case that it handles
  41 // poorly, but which is thought to be rare.  The profile provides
  42 // evidence of this rarity for a given method or even BCI.  It allows
  43 // the compiler to back out of the optimization at places where it
  44 // has historically been a poor choice.  Other heuristics try to use
  45 // specific information gathered about types observed at a given site.
  46 //
  47 // All data in the profile is approximate.  It is expected to be accurate
  48 // on the whole, but the system expects occasional inaccuraces, due to
  49 // counter overflow, multiprocessor races during data collection, space
  50 // limitations, missing MDO blocks, etc.  Bad or missing data will degrade
  51 // optimization quality but will not affect correctness.  Also, each MDO
  52 // is marked with its birth-date ("creation_mileage") which can be used
  53 // to assess the quality ("maturity") of its data.
  54 //
  55 // Short (<32-bit) counters are designed to overflow to a known "saturated"
  56 // state.  Also, certain recorded per-BCI events are given one-bit counters
  57 // which overflow to a saturated state which applied to all counters at
  58 // that BCI.  In other words, there is a small lattice which approximates
  59 // the ideal of an infinite-precision counter for each event at each BCI,
  60 // and the lattice quickly "bottoms out" in a state where all counters
  61 // are taken to be indefinitely large.
  62 //
  63 // The reader will find many data races in profile gathering code, starting
  64 // with invocation counter incrementation.  None of these races harm correct
  65 // execution of the compiled code.
  66 
  67 // forward decl
  68 class ProfileData;
  69 
  70 // DataLayout
  71 //
  72 // Overlay for generic profiling data.
  73 class DataLayout VALUE_OBJ_CLASS_SPEC {
  74 private:
  75   // Every data layout begins with a header.  This header
  76   // contains a tag, which is used to indicate the size/layout
  77   // of the data, 3 bits of flags, which can be used in any way,
  78   // 5 bits of trap history (none/one reason/many reasons),
  79   // and a bci, which is used to tie this piece of data to a
  80   // specific bci in the bytecodes.
  81   union {
  82     intptr_t _bits;
  83     struct {
  84       u1 _tag;
  85       u1 _flags;
  86       u2 _bci;
  87     } _struct;
  88   } _header;
  89 
  90   // The data layout has an arbitrary number of cells, each sized
  91   // to accomodate a pointer or an integer.
  92   intptr_t _cells[1];
  93 
  94   // Some types of data layouts need a length field.
  95   static bool needs_array_len(u1 tag);
  96 
  97 public:
  98   enum {
  99     counter_increment = 1
 100   };
 101 
 102   enum {
 103     cell_size = sizeof(intptr_t)
 104   };
 105 
 106   // Tag values
 107   enum {
 108     no_tag,
 109     bit_data_tag,
 110     counter_data_tag,
 111     jump_data_tag,
 112     receiver_type_data_tag,
 113     virtual_call_data_tag,
 114     ret_data_tag,
 115     branch_data_tag,
 116     multi_branch_data_tag,
 117     arg_info_data_tag
 118   };
 119 
 120   enum {
 121     // The _struct._flags word is formatted as [trap_state:5 | flags:3].
 122     // The trap state breaks down further as [recompile:1 | reason:4].
 123     // This further breakdown is defined in deoptimization.cpp.
 124     // See Deoptimization::trap_state_reason for an assert that
 125     // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
 126     //
 127     // The trap_state is collected only if ProfileTraps is true.
 128     trap_bits = 1+4,  // 4: enough to distinguish [0..Reason_RECORDED_LIMIT].
 129     trap_shift = BitsPerByte - trap_bits,
 130     trap_mask = right_n_bits(trap_bits),
 131     trap_mask_in_place = (trap_mask << trap_shift),
 132     flag_limit = trap_shift,
 133     flag_mask = right_n_bits(flag_limit),
 134     first_flag = 0
 135   };
 136 
 137   // Size computation
 138   static int header_size_in_bytes() {
 139     return cell_size;
 140   }
 141   static int header_size_in_cells() {
 142     return 1;
 143   }
 144 
 145   static int compute_size_in_bytes(int cell_count) {
 146     return header_size_in_bytes() + cell_count * cell_size;
 147   }
 148 
 149   // Initialization
 150   void initialize(u1 tag, u2 bci, int cell_count);
 151 
 152   // Accessors
 153   u1 tag() {
 154     return _header._struct._tag;
 155   }
 156 
 157   // Return a few bits of trap state.  Range is [0..trap_mask].
 158   // The state tells if traps with zero, one, or many reasons have occurred.
 159   // It also tells whether zero or many recompilations have occurred.
 160   // The associated trap histogram in the MDO itself tells whether
 161   // traps are common or not.  If a BCI shows that a trap X has
 162   // occurred, and the MDO shows N occurrences of X, we make the
 163   // simplifying assumption that all N occurrences can be blamed
 164   // on that BCI.
 165   int trap_state() {
 166     return ((_header._struct._flags >> trap_shift) & trap_mask);
 167   }
 168 
 169   void set_trap_state(int new_state) {
 170     assert(ProfileTraps, "used only under +ProfileTraps");
 171     uint old_flags = (_header._struct._flags & flag_mask);
 172     _header._struct._flags = (new_state << trap_shift) | old_flags;
 173   }
 174 
 175   u1 flags() {
 176     return _header._struct._flags;
 177   }
 178 
 179   u2 bci() {
 180     return _header._struct._bci;
 181   }
 182 
 183   void set_header(intptr_t value) {
 184     _header._bits = value;
 185   }
 186   void release_set_header(intptr_t value) {
 187     OrderAccess::release_store_ptr(&_header._bits, value);
 188   }
 189   intptr_t header() {
 190     return _header._bits;
 191   }
 192   void set_cell_at(int index, intptr_t value) {
 193     _cells[index] = value;
 194   }
 195   void release_set_cell_at(int index, intptr_t value) {
 196     OrderAccess::release_store_ptr(&_cells[index], value);
 197   }
 198   intptr_t cell_at(int index) {
 199     return _cells[index];
 200   }
 201   intptr_t* adr_cell_at(int index) {
 202     return &_cells[index];
 203   }
 204   oop* adr_oop_at(int index) {
 205     return (oop*)&(_cells[index]);
 206   }
 207 
 208   void set_flag_at(int flag_number) {
 209     assert(flag_number < flag_limit, "oob");
 210     _header._struct._flags |= (0x1 << flag_number);
 211   }
 212   bool flag_at(int flag_number) {
 213     assert(flag_number < flag_limit, "oob");
 214     return (_header._struct._flags & (0x1 << flag_number)) != 0;
 215   }
 216 
 217   // Low-level support for code generation.
 218   static ByteSize header_offset() {
 219     return byte_offset_of(DataLayout, _header);
 220   }
 221   static ByteSize tag_offset() {
 222     return byte_offset_of(DataLayout, _header._struct._tag);
 223   }
 224   static ByteSize flags_offset() {
 225     return byte_offset_of(DataLayout, _header._struct._flags);
 226   }
 227   static ByteSize bci_offset() {
 228     return byte_offset_of(DataLayout, _header._struct._bci);
 229   }
 230   static ByteSize cell_offset(int index) {
 231     return byte_offset_of(DataLayout, _cells) + in_ByteSize(index * cell_size);
 232   }
 233   // Return a value which, when or-ed as a byte into _flags, sets the flag.
 234   static int flag_number_to_byte_constant(int flag_number) {
 235     assert(0 <= flag_number && flag_number < flag_limit, "oob");
 236     DataLayout temp; temp.set_header(0);
 237     temp.set_flag_at(flag_number);
 238     return temp._header._struct._flags;
 239   }
 240   // Return a value which, when or-ed as a word into _header, sets the flag.
 241   static intptr_t flag_mask_to_header_mask(int byte_constant) {
 242     DataLayout temp; temp.set_header(0);
 243     temp._header._struct._flags = byte_constant;
 244     return temp._header._bits;
 245   }
 246 
 247   // GC support
 248   ProfileData* data_in();
 249   void follow_weak_refs(BoolObjectClosure* cl);
 250 };
 251 
 252 
 253 // ProfileData class hierarchy
 254 class ProfileData;
 255 class   BitData;
 256 class     CounterData;
 257 class       ReceiverTypeData;
 258 class         VirtualCallData;
 259 class       RetData;
 260 class   JumpData;
 261 class     BranchData;
 262 class   ArrayData;
 263 class     MultiBranchData;
 264 class     ArgInfoData;
 265 
 266 
 267 // ProfileData
 268 //
 269 // A ProfileData object is created to refer to a section of profiling
 270 // data in a structured way.
 271 class ProfileData : public ResourceObj {
 272 private:
 273 #ifndef PRODUCT
 274   enum {
 275     tab_width_one = 16,
 276     tab_width_two = 36
 277   };
 278 #endif // !PRODUCT
 279 
 280   // This is a pointer to a section of profiling data.
 281   DataLayout* _data;
 282 
 283 protected:
 284   DataLayout* data() { return _data; }
 285 
 286   enum {
 287     cell_size = DataLayout::cell_size
 288   };
 289 
 290 public:
 291   // How many cells are in this?
 292   virtual int cell_count() {
 293     ShouldNotReachHere();
 294     return -1;
 295   }
 296 
 297   // Return the size of this data.
 298   int size_in_bytes() {
 299     return DataLayout::compute_size_in_bytes(cell_count());
 300   }
 301 
 302 protected:
 303   // Low-level accessors for underlying data
 304   void set_intptr_at(int index, intptr_t value) {
 305     assert(0 <= index && index < cell_count(), "oob");
 306     data()->set_cell_at(index, value);
 307   }
 308   void release_set_intptr_at(int index, intptr_t value) {
 309     assert(0 <= index && index < cell_count(), "oob");
 310     data()->release_set_cell_at(index, value);
 311   }
 312   intptr_t intptr_at(int index) {
 313     assert(0 <= index && index < cell_count(), "oob");
 314     return data()->cell_at(index);
 315   }
 316   void set_uint_at(int index, uint value) {
 317     set_intptr_at(index, (intptr_t) value);
 318   }
 319   void release_set_uint_at(int index, uint value) {
 320     release_set_intptr_at(index, (intptr_t) value);
 321   }
 322   uint uint_at(int index) {
 323     return (uint)intptr_at(index);
 324   }
 325   void set_int_at(int index, int value) {
 326     set_intptr_at(index, (intptr_t) value);
 327   }
 328   void release_set_int_at(int index, int value) {
 329     release_set_intptr_at(index, (intptr_t) value);
 330   }
 331   int int_at(int index) {
 332     return (int)intptr_at(index);
 333   }
 334   int int_at_unchecked(int index) {
 335     return (int)data()->cell_at(index);
 336   }
 337   void set_oop_at(int index, oop value) {
 338     set_intptr_at(index, (intptr_t) value);
 339   }
 340   oop oop_at(int index) {
 341     return (oop)intptr_at(index);
 342   }
 343   oop* adr_oop_at(int index) {
 344     assert(0 <= index && index < cell_count(), "oob");
 345     return data()->adr_oop_at(index);
 346   }
 347 
 348   void set_flag_at(int flag_number) {
 349     data()->set_flag_at(flag_number);
 350   }
 351   bool flag_at(int flag_number) {
 352     return data()->flag_at(flag_number);
 353   }
 354 
 355   // two convenient imports for use by subclasses:
 356   static ByteSize cell_offset(int index) {
 357     return DataLayout::cell_offset(index);
 358   }
 359   static int flag_number_to_byte_constant(int flag_number) {
 360     return DataLayout::flag_number_to_byte_constant(flag_number);
 361   }
 362 
 363   ProfileData(DataLayout* data) {
 364     _data = data;
 365   }
 366 
 367 public:
 368   // Constructor for invalid ProfileData.
 369   ProfileData();
 370 
 371   u2 bci() {
 372     return data()->bci();
 373   }
 374 
 375   address dp() {
 376     return (address)_data;
 377   }
 378 
 379   int trap_state() {
 380     return data()->trap_state();
 381   }
 382   void set_trap_state(int new_state) {
 383     data()->set_trap_state(new_state);
 384   }
 385 
 386   // Type checking
 387   virtual bool is_BitData()         { return false; }
 388   virtual bool is_CounterData()     { return false; }
 389   virtual bool is_JumpData()        { return false; }
 390   virtual bool is_ReceiverTypeData(){ return false; }
 391   virtual bool is_VirtualCallData() { return false; }
 392   virtual bool is_RetData()         { return false; }
 393   virtual bool is_BranchData()      { return false; }
 394   virtual bool is_ArrayData()       { return false; }
 395   virtual bool is_MultiBranchData() { return false; }
 396   virtual bool is_ArgInfoData()     { return false; }
 397 
 398 
 399   BitData* as_BitData() {
 400     assert(is_BitData(), "wrong type");
 401     return is_BitData()         ? (BitData*)        this : NULL;
 402   }
 403   CounterData* as_CounterData() {
 404     assert(is_CounterData(), "wrong type");
 405     return is_CounterData()     ? (CounterData*)    this : NULL;
 406   }
 407   JumpData* as_JumpData() {
 408     assert(is_JumpData(), "wrong type");
 409     return is_JumpData()        ? (JumpData*)       this : NULL;
 410   }
 411   ReceiverTypeData* as_ReceiverTypeData() {
 412     assert(is_ReceiverTypeData(), "wrong type");
 413     return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
 414   }
 415   VirtualCallData* as_VirtualCallData() {
 416     assert(is_VirtualCallData(), "wrong type");
 417     return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
 418   }
 419   RetData* as_RetData() {
 420     assert(is_RetData(), "wrong type");
 421     return is_RetData()         ? (RetData*)        this : NULL;
 422   }
 423   BranchData* as_BranchData() {
 424     assert(is_BranchData(), "wrong type");
 425     return is_BranchData()      ? (BranchData*)     this : NULL;
 426   }
 427   ArrayData* as_ArrayData() {
 428     assert(is_ArrayData(), "wrong type");
 429     return is_ArrayData()       ? (ArrayData*)      this : NULL;
 430   }
 431   MultiBranchData* as_MultiBranchData() {
 432     assert(is_MultiBranchData(), "wrong type");
 433     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
 434   }
 435   ArgInfoData* as_ArgInfoData() {
 436     assert(is_ArgInfoData(), "wrong type");
 437     return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
 438   }
 439 
 440 
 441   // Subclass specific initialization
 442   virtual void post_initialize(BytecodeStream* stream, methodDataOop mdo) {}
 443 
 444   // GC support
 445   virtual void follow_contents() {}
 446   virtual void oop_iterate(OopClosure* blk) {}
 447   virtual void oop_iterate_m(OopClosure* blk, MemRegion mr) {}
 448   virtual void adjust_pointers() {}
 449   virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure) {}
 450 
 451 #ifndef SERIALGC
 452   // Parallel old support
 453   virtual void follow_contents(ParCompactionManager* cm) {}
 454   virtual void update_pointers() {}
 455 #endif // SERIALGC
 456 
 457   // CI translation: ProfileData can represent both MethodDataOop data
 458   // as well as CIMethodData data. This function is provided for translating
 459   // an oop in a ProfileData to the ci equivalent. Generally speaking,
 460   // most ProfileData don't require any translation, so we provide the null
 461   // translation here, and the required translators are in the ci subclasses.
 462   virtual void translate_from(ProfileData* data) {}
 463 
 464   virtual void print_data_on(outputStream* st) {
 465     ShouldNotReachHere();
 466   }
 467 
 468 #ifndef PRODUCT
 469   void print_shared(outputStream* st, const char* name);
 470   void tab(outputStream* st);
 471 #endif
 472 };
 473 
 474 // BitData
 475 //
 476 // A BitData holds a flag or two in its header.
 477 class BitData : public ProfileData {
 478 protected:
 479   enum {
 480     // null_seen:
 481     //  saw a null operand (cast/aastore/instanceof)
 482     null_seen_flag              = DataLayout::first_flag + 0
 483   };
 484   enum { bit_cell_count = 0 };  // no additional data fields needed.
 485 public:
 486   BitData(DataLayout* layout) : ProfileData(layout) {
 487   }
 488 
 489   virtual bool is_BitData() { return true; }
 490 
 491   static int static_cell_count() {
 492     return bit_cell_count;
 493   }
 494 
 495   virtual int cell_count() {
 496     return static_cell_count();
 497   }
 498 
 499   // Accessor
 500 
 501   // The null_seen flag bit is specially known to the interpreter.
 502   // Consulting it allows the compiler to avoid setting up null_check traps.
 503   bool null_seen()     { return flag_at(null_seen_flag); }
 504   void set_null_seen()    { set_flag_at(null_seen_flag); }
 505 
 506 
 507   // Code generation support
 508   static int null_seen_byte_constant() {
 509     return flag_number_to_byte_constant(null_seen_flag);
 510   }
 511 
 512   static ByteSize bit_data_size() {
 513     return cell_offset(bit_cell_count);
 514   }
 515 
 516 #ifndef PRODUCT
 517   void print_data_on(outputStream* st);
 518 #endif
 519 };
 520 
 521 // CounterData
 522 //
 523 // A CounterData corresponds to a simple counter.
 524 class CounterData : public BitData {
 525 protected:
 526   enum {
 527     count_off,
 528     counter_cell_count
 529   };
 530 public:
 531   CounterData(DataLayout* layout) : BitData(layout) {}
 532 
 533   virtual bool is_CounterData() { return true; }
 534 
 535   static int static_cell_count() {
 536     return counter_cell_count;
 537   }
 538 
 539   virtual int cell_count() {
 540     return static_cell_count();
 541   }
 542 
 543   // Direct accessor
 544   uint count() {
 545     return uint_at(count_off);
 546   }
 547 
 548   // Code generation support
 549   static ByteSize count_offset() {
 550     return cell_offset(count_off);
 551   }
 552   static ByteSize counter_data_size() {
 553     return cell_offset(counter_cell_count);
 554   }
 555 
 556   void set_count(uint count) {
 557     set_uint_at(count_off, count);
 558   }
 559 
 560 #ifndef PRODUCT
 561   void print_data_on(outputStream* st);
 562 #endif
 563 };
 564 
 565 // JumpData
 566 //
 567 // A JumpData is used to access profiling information for a direct
 568 // branch.  It is a counter, used for counting the number of branches,
 569 // plus a data displacement, used for realigning the data pointer to
 570 // the corresponding target bci.
 571 class JumpData : public ProfileData {
 572 protected:
 573   enum {
 574     taken_off_set,
 575     displacement_off_set,
 576     jump_cell_count
 577   };
 578 
 579   void set_displacement(int displacement) {
 580     set_int_at(displacement_off_set, displacement);
 581   }
 582 
 583 public:
 584   JumpData(DataLayout* layout) : ProfileData(layout) {
 585     assert(layout->tag() == DataLayout::jump_data_tag ||
 586       layout->tag() == DataLayout::branch_data_tag, "wrong type");
 587   }
 588 
 589   virtual bool is_JumpData() { return true; }
 590 
 591   static int static_cell_count() {
 592     return jump_cell_count;
 593   }
 594 
 595   virtual int cell_count() {
 596     return static_cell_count();
 597   }
 598 
 599   // Direct accessor
 600   uint taken() {
 601     return uint_at(taken_off_set);
 602   }
 603   // Saturating counter
 604   uint inc_taken() {
 605     uint cnt = taken() + 1;
 606     // Did we wrap? Will compiler screw us??
 607     if (cnt == 0) cnt--;
 608     set_uint_at(taken_off_set, cnt);
 609     return cnt;
 610   }
 611 
 612   int displacement() {
 613     return int_at(displacement_off_set);
 614   }
 615 
 616   // Code generation support
 617   static ByteSize taken_offset() {
 618     return cell_offset(taken_off_set);
 619   }
 620 
 621   static ByteSize displacement_offset() {
 622     return cell_offset(displacement_off_set);
 623   }
 624 
 625   // Specific initialization.
 626   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 627 
 628 #ifndef PRODUCT
 629   void print_data_on(outputStream* st);
 630 #endif
 631 };
 632 
 633 // ReceiverTypeData
 634 //
 635 // A ReceiverTypeData is used to access profiling information about a
 636 // dynamic type check.  It consists of a counter which counts the total times
 637 // that the check is reached, and a series of (klassOop, count) pairs
 638 // which are used to store a type profile for the receiver of the check.
 639 class ReceiverTypeData : public CounterData {
 640 protected:
 641   enum {
 642     receiver0_offset = counter_cell_count,
 643     count0_offset,
 644     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
 645   };
 646 
 647 public:
 648   ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
 649     assert(layout->tag() == DataLayout::receiver_type_data_tag ||
 650            layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
 651   }
 652 
 653   virtual bool is_ReceiverTypeData() { return true; }
 654 
 655   static int static_cell_count() {
 656     return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
 657   }
 658 
 659   virtual int cell_count() {
 660     return static_cell_count();
 661   }
 662 
 663   // Direct accessors
 664   static uint row_limit() {
 665     return TypeProfileWidth;
 666   }
 667   static int receiver_cell_index(uint row) {
 668     return receiver0_offset + row * receiver_type_row_cell_count;
 669   }
 670   static int receiver_count_cell_index(uint row) {
 671     return count0_offset + row * receiver_type_row_cell_count;
 672   }
 673 
 674   // Get the receiver at row.  The 'unchecked' version is needed by parallel old
 675   // gc; it does not assert the receiver is a klass.  During compaction of the
 676   // perm gen, the klass may already have moved, so the is_klass() predicate
 677   // would fail.  The 'normal' version should be used whenever possible.
 678   klassOop receiver_unchecked(uint row) {
 679     assert(row < row_limit(), "oob");
 680     oop recv = oop_at(receiver_cell_index(row));
 681     return (klassOop)recv;
 682   }
 683 
 684   klassOop receiver(uint row) {
 685     klassOop recv = receiver_unchecked(row);
 686     assert(recv == NULL || ((oop)recv)->is_klass(), "wrong type");
 687     return recv;
 688   }
 689 
 690   void set_receiver(uint row, oop p) {
 691     assert((uint)row < row_limit(), "oob");
 692     set_oop_at(receiver_cell_index(row), p);
 693   }
 694 
 695   uint receiver_count(uint row) {
 696     assert(row < row_limit(), "oob");
 697     return uint_at(receiver_count_cell_index(row));
 698   }
 699 
 700   void set_receiver_count(uint row, uint count) {
 701     assert(row < row_limit(), "oob");
 702     set_uint_at(receiver_count_cell_index(row), count);
 703   }
 704 
 705   void clear_row(uint row) {
 706     assert(row < row_limit(), "oob");
 707     // Clear total count - indicator of polymorphic call site.
 708     // The site may look like as monomorphic after that but
 709     // it allow to have more accurate profiling information because
 710     // there was execution phase change since klasses were unloaded.
 711     // If the site is still polymorphic then MDO will be updated
 712     // to reflect it. But it could be the case that the site becomes
 713     // only bimorphic. Then keeping total count not 0 will be wrong.
 714     // Even if we use monomorphic (when it is not) for compilation
 715     // we will only have trap, deoptimization and recompile again
 716     // with updated MDO after executing method in Interpreter.
 717     // An additional receiver will be recorded in the cleaned row
 718     // during next call execution.
 719     //
 720     // Note: our profiling logic works with empty rows in any slot.
 721     // We do sorting a profiling info (ciCallProfile) for compilation.
 722     //
 723     set_count(0);
 724     set_receiver(row, NULL);
 725     set_receiver_count(row, 0);
 726   }
 727 
 728   // Code generation support
 729   static ByteSize receiver_offset(uint row) {
 730     return cell_offset(receiver_cell_index(row));
 731   }
 732   static ByteSize receiver_count_offset(uint row) {
 733     return cell_offset(receiver_count_cell_index(row));
 734   }
 735   static ByteSize receiver_type_data_size() {
 736     return cell_offset(static_cell_count());
 737   }
 738 
 739   // GC support
 740   virtual void follow_contents();
 741   virtual void oop_iterate(OopClosure* blk);
 742   virtual void oop_iterate_m(OopClosure* blk, MemRegion mr);
 743   virtual void adjust_pointers();
 744   virtual void follow_weak_refs(BoolObjectClosure* is_alive_closure);
 745 
 746 #ifndef SERIALGC
 747   // Parallel old support
 748   virtual void follow_contents(ParCompactionManager* cm);
 749   virtual void update_pointers();
 750 #endif // SERIALGC
 751 
 752   oop* adr_receiver(uint row) {
 753     return adr_oop_at(receiver_cell_index(row));
 754   }
 755 
 756 #ifndef PRODUCT
 757   void print_receiver_data_on(outputStream* st);
 758   void print_data_on(outputStream* st);
 759 #endif
 760 };
 761 
 762 // VirtualCallData
 763 //
 764 // A VirtualCallData is used to access profiling information about a
 765 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
 766 class VirtualCallData : public ReceiverTypeData {
 767 public:
 768   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
 769     assert(layout->tag() == DataLayout::virtual_call_data_tag, "wrong type");
 770   }
 771 
 772   virtual bool is_VirtualCallData() { return true; }
 773 
 774   static int static_cell_count() {
 775     // At this point we could add more profile state, e.g., for arguments.
 776     // But for now it's the same size as the base record type.
 777     return ReceiverTypeData::static_cell_count();
 778   }
 779 
 780   virtual int cell_count() {
 781     return static_cell_count();
 782   }
 783 
 784   // Direct accessors
 785   static ByteSize virtual_call_data_size() {
 786     return cell_offset(static_cell_count());
 787   }
 788 
 789 #ifndef PRODUCT
 790   void print_data_on(outputStream* st);
 791 #endif
 792 };
 793 
 794 // RetData
 795 //
 796 // A RetData is used to access profiling information for a ret bytecode.
 797 // It is composed of a count of the number of times that the ret has
 798 // been executed, followed by a series of triples of the form
 799 // (bci, count, di) which count the number of times that some bci was the
 800 // target of the ret and cache a corresponding data displacement.
 801 class RetData : public CounterData {
 802 protected:
 803   enum {
 804     bci0_offset = counter_cell_count,
 805     count0_offset,
 806     displacement0_offset,
 807     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
 808   };
 809 
 810   void set_bci(uint row, int bci) {
 811     assert((uint)row < row_limit(), "oob");
 812     set_int_at(bci0_offset + row * ret_row_cell_count, bci);
 813   }
 814   void release_set_bci(uint row, int bci) {
 815     assert((uint)row < row_limit(), "oob");
 816     // 'release' when setting the bci acts as a valid flag for other
 817     // threads wrt bci_count and bci_displacement.
 818     release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
 819   }
 820   void set_bci_count(uint row, uint count) {
 821     assert((uint)row < row_limit(), "oob");
 822     set_uint_at(count0_offset + row * ret_row_cell_count, count);
 823   }
 824   void set_bci_displacement(uint row, int disp) {
 825     set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
 826   }
 827 
 828 public:
 829   RetData(DataLayout* layout) : CounterData(layout) {
 830     assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
 831   }
 832 
 833   virtual bool is_RetData() { return true; }
 834 
 835   enum {
 836     no_bci = -1 // value of bci when bci1/2 are not in use.
 837   };
 838 
 839   static int static_cell_count() {
 840     return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
 841   }
 842 
 843   virtual int cell_count() {
 844     return static_cell_count();
 845   }
 846 
 847   static uint row_limit() {
 848     return BciProfileWidth;
 849   }
 850   static int bci_cell_index(uint row) {
 851     return bci0_offset + row * ret_row_cell_count;
 852   }
 853   static int bci_count_cell_index(uint row) {
 854     return count0_offset + row * ret_row_cell_count;
 855   }
 856   static int bci_displacement_cell_index(uint row) {
 857     return displacement0_offset + row * ret_row_cell_count;
 858   }
 859 
 860   // Direct accessors
 861   int bci(uint row) {
 862     return int_at(bci_cell_index(row));
 863   }
 864   uint bci_count(uint row) {
 865     return uint_at(bci_count_cell_index(row));
 866   }
 867   int bci_displacement(uint row) {
 868     return int_at(bci_displacement_cell_index(row));
 869   }
 870 
 871   // Interpreter Runtime support
 872   address fixup_ret(int return_bci, methodDataHandle mdo);
 873 
 874   // Code generation support
 875   static ByteSize bci_offset(uint row) {
 876     return cell_offset(bci_cell_index(row));
 877   }
 878   static ByteSize bci_count_offset(uint row) {
 879     return cell_offset(bci_count_cell_index(row));
 880   }
 881   static ByteSize bci_displacement_offset(uint row) {
 882     return cell_offset(bci_displacement_cell_index(row));
 883   }
 884 
 885   // Specific initialization.
 886   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 887 
 888 #ifndef PRODUCT
 889   void print_data_on(outputStream* st);
 890 #endif
 891 };
 892 
 893 // BranchData
 894 //
 895 // A BranchData is used to access profiling data for a two-way branch.
 896 // It consists of taken and not_taken counts as well as a data displacement
 897 // for the taken case.
 898 class BranchData : public JumpData {
 899 protected:
 900   enum {
 901     not_taken_off_set = jump_cell_count,
 902     branch_cell_count
 903   };
 904 
 905   void set_displacement(int displacement) {
 906     set_int_at(displacement_off_set, displacement);
 907   }
 908 
 909 public:
 910   BranchData(DataLayout* layout) : JumpData(layout) {
 911     assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
 912   }
 913 
 914   virtual bool is_BranchData() { return true; }
 915 
 916   static int static_cell_count() {
 917     return branch_cell_count;
 918   }
 919 
 920   virtual int cell_count() {
 921     return static_cell_count();
 922   }
 923 
 924   // Direct accessor
 925   uint not_taken() {
 926     return uint_at(not_taken_off_set);
 927   }
 928 
 929   uint inc_not_taken() {
 930     uint cnt = not_taken() + 1;
 931     // Did we wrap? Will compiler screw us??
 932     if (cnt == 0) cnt--;
 933     set_uint_at(not_taken_off_set, cnt);
 934     return cnt;
 935   }
 936 
 937   // Code generation support
 938   static ByteSize not_taken_offset() {
 939     return cell_offset(not_taken_off_set);
 940   }
 941   static ByteSize branch_data_size() {
 942     return cell_offset(branch_cell_count);
 943   }
 944 
 945   // Specific initialization.
 946   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
 947 
 948 #ifndef PRODUCT
 949   void print_data_on(outputStream* st);
 950 #endif
 951 };
 952 
 953 // ArrayData
 954 //
 955 // A ArrayData is a base class for accessing profiling data which does
 956 // not have a statically known size.  It consists of an array length
 957 // and an array start.
 958 class ArrayData : public ProfileData {
 959 protected:
 960   friend class DataLayout;
 961 
 962   enum {
 963     array_len_off_set,
 964     array_start_off_set
 965   };
 966 
 967   uint array_uint_at(int index) {
 968     int aindex = index + array_start_off_set;
 969     return uint_at(aindex);
 970   }
 971   int array_int_at(int index) {
 972     int aindex = index + array_start_off_set;
 973     return int_at(aindex);
 974   }
 975   oop array_oop_at(int index) {
 976     int aindex = index + array_start_off_set;
 977     return oop_at(aindex);
 978   }
 979   void array_set_int_at(int index, int value) {
 980     int aindex = index + array_start_off_set;
 981     set_int_at(aindex, value);
 982   }
 983 
 984   // Code generation support for subclasses.
 985   static ByteSize array_element_offset(int index) {
 986     return cell_offset(array_start_off_set + index);
 987   }
 988 
 989 public:
 990   ArrayData(DataLayout* layout) : ProfileData(layout) {}
 991 
 992   virtual bool is_ArrayData() { return true; }
 993 
 994   static int static_cell_count() {
 995     return -1;
 996   }
 997 
 998   int array_len() {
 999     return int_at_unchecked(array_len_off_set);
1000   }
1001 
1002   virtual int cell_count() {
1003     return array_len() + 1;
1004   }
1005 
1006   // Code generation support
1007   static ByteSize array_len_offset() {
1008     return cell_offset(array_len_off_set);
1009   }
1010   static ByteSize array_start_offset() {
1011     return cell_offset(array_start_off_set);
1012   }
1013 };
1014 
1015 // MultiBranchData
1016 //
1017 // A MultiBranchData is used to access profiling information for
1018 // a multi-way branch (*switch bytecodes).  It consists of a series
1019 // of (count, displacement) pairs, which count the number of times each
1020 // case was taken and specify the data displacment for each branch target.
1021 class MultiBranchData : public ArrayData {
1022 protected:
1023   enum {
1024     default_count_off_set,
1025     default_disaplacement_off_set,
1026     case_array_start
1027   };
1028   enum {
1029     relative_count_off_set,
1030     relative_displacement_off_set,
1031     per_case_cell_count
1032   };
1033 
1034   void set_default_displacement(int displacement) {
1035     array_set_int_at(default_disaplacement_off_set, displacement);
1036   }
1037   void set_displacement_at(int index, int displacement) {
1038     array_set_int_at(case_array_start +
1039                      index * per_case_cell_count +
1040                      relative_displacement_off_set,
1041                      displacement);
1042   }
1043 
1044 public:
1045   MultiBranchData(DataLayout* layout) : ArrayData(layout) {
1046     assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
1047   }
1048 
1049   virtual bool is_MultiBranchData() { return true; }
1050 
1051   static int compute_cell_count(BytecodeStream* stream);
1052 
1053   int number_of_cases() {
1054     int alen = array_len() - 2; // get rid of default case here.
1055     assert(alen % per_case_cell_count == 0, "must be even");
1056     return (alen / per_case_cell_count);
1057   }
1058 
1059   uint default_count() {
1060     return array_uint_at(default_count_off_set);
1061   }
1062   int default_displacement() {
1063     return array_int_at(default_disaplacement_off_set);
1064   }
1065 
1066   uint count_at(int index) {
1067     return array_uint_at(case_array_start +
1068                          index * per_case_cell_count +
1069                          relative_count_off_set);
1070   }
1071   int displacement_at(int index) {
1072     return array_int_at(case_array_start +
1073                         index * per_case_cell_count +
1074                         relative_displacement_off_set);
1075   }
1076 
1077   // Code generation support
1078   static ByteSize default_count_offset() {
1079     return array_element_offset(default_count_off_set);
1080   }
1081   static ByteSize default_displacement_offset() {
1082     return array_element_offset(default_disaplacement_off_set);
1083   }
1084   static ByteSize case_count_offset(int index) {
1085     return case_array_offset() +
1086            (per_case_size() * index) +
1087            relative_count_offset();
1088   }
1089   static ByteSize case_array_offset() {
1090     return array_element_offset(case_array_start);
1091   }
1092   static ByteSize per_case_size() {
1093     return in_ByteSize(per_case_cell_count) * cell_size;
1094   }
1095   static ByteSize relative_count_offset() {
1096     return in_ByteSize(relative_count_off_set) * cell_size;
1097   }
1098   static ByteSize relative_displacement_offset() {
1099     return in_ByteSize(relative_displacement_off_set) * cell_size;
1100   }
1101 
1102   // Specific initialization.
1103   void post_initialize(BytecodeStream* stream, methodDataOop mdo);
1104 
1105 #ifndef PRODUCT
1106   void print_data_on(outputStream* st);
1107 #endif
1108 };
1109 
1110 class ArgInfoData : public ArrayData {
1111 
1112 public:
1113   ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1114     assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1115   }
1116 
1117   virtual bool is_ArgInfoData() { return true; }
1118 
1119 
1120   int number_of_args() {
1121     return array_len();
1122   }
1123 
1124   uint arg_modified(int arg) {
1125     return array_uint_at(arg);
1126   }
1127 
1128   void set_arg_modified(int arg, uint val) {
1129     array_set_int_at(arg, val);
1130   }
1131 
1132 #ifndef PRODUCT
1133   void print_data_on(outputStream* st);
1134 #endif
1135 };
1136 
1137 // methodDataOop
1138 //
1139 // A methodDataOop holds information which has been collected about
1140 // a method.  Its layout looks like this:
1141 //
1142 // -----------------------------
1143 // | header                    |
1144 // | klass                     |
1145 // -----------------------------
1146 // | method                    |
1147 // | size of the methodDataOop |
1148 // -----------------------------
1149 // | Data entries...           |
1150 // |   (variable size)         |
1151 // |                           |
1152 // .                           .
1153 // .                           .
1154 // .                           .
1155 // |                           |
1156 // -----------------------------
1157 //
1158 // The data entry area is a heterogeneous array of DataLayouts. Each
1159 // DataLayout in the array corresponds to a specific bytecode in the
1160 // method.  The entries in the array are sorted by the corresponding
1161 // bytecode.  Access to the data is via resource-allocated ProfileData,
1162 // which point to the underlying blocks of DataLayout structures.
1163 //
1164 // During interpretation, if profiling in enabled, the interpreter
1165 // maintains a method data pointer (mdp), which points at the entry
1166 // in the array corresponding to the current bci.  In the course of
1167 // intepretation, when a bytecode is encountered that has profile data
1168 // associated with it, the entry pointed to by mdp is updated, then the
1169 // mdp is adjusted to point to the next appropriate DataLayout.  If mdp
1170 // is NULL to begin with, the interpreter assumes that the current method
1171 // is not (yet) being profiled.
1172 //
1173 // In methodDataOop parlance, "dp" is a "data pointer", the actual address
1174 // of a DataLayout element.  A "di" is a "data index", the offset in bytes
1175 // from the base of the data entry array.  A "displacement" is the byte offset
1176 // in certain ProfileData objects that indicate the amount the mdp must be
1177 // adjusted in the event of a change in control flow.
1178 //
1179 
1180 class methodDataOopDesc : public oopDesc {
1181   friend class VMStructs;
1182 private:
1183   friend class ProfileData;
1184 
1185   // Back pointer to the methodOop
1186   methodOop _method;
1187 
1188   // Size of this oop in bytes
1189   int _size;
1190 
1191   // Cached hint for bci_to_dp and bci_to_data
1192   int _hint_di;
1193 
1194   // Whole-method sticky bits and flags
1195 public:
1196   enum {
1197     _trap_hist_limit    = 17,   // decoupled from Deoptimization::Reason_LIMIT
1198     _trap_hist_mask     = max_jubyte,
1199     _extra_data_count   = 4     // extra DataLayout headers, for trap history
1200   }; // Public flag values
1201 private:
1202   uint _nof_decompiles;             // count of all nmethod removals
1203   uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
1204   uint _nof_overflow_traps;         // trap count, excluding _trap_hist
1205   union {
1206     intptr_t _align;
1207     u1 _array[_trap_hist_limit];
1208   } _trap_hist;
1209 
1210   // Support for interprocedural escape analysis, from Thomas Kotzmann.
1211   intx              _eflags;          // flags on escape information
1212   intx              _arg_local;       // bit set of non-escaping arguments
1213   intx              _arg_stack;       // bit set of stack-allocatable arguments
1214   intx              _arg_returned;    // bit set of returned arguments
1215 
1216   int _creation_mileage;              // method mileage at MDO creation
1217 
1218   // How many invocations has this MDO seen?
1219   // These counters are used to determine the exact age of MDO.
1220   // We need those because in tiered a method can be concurrently
1221   // executed at different levels.
1222   InvocationCounter _invocation_counter;
1223   // Same for backedges.
1224   InvocationCounter _backedge_counter;
1225   // Counter values at the time profiling started.
1226   int               _invocation_counter_start;
1227   int               _backedge_counter_start;
1228   // Number of loops and blocks is computed when compiling the first
1229   // time with C1. It is used to determine if method is trivial.
1230   short             _num_loops;
1231   short             _num_blocks;
1232   // Highest compile level this method has ever seen.
1233   u1                _highest_comp_level;
1234   // Same for OSR level
1235   u1                _highest_osr_comp_level;
1236   // Does this method contain anything worth profiling?
1237   bool              _would_profile;
1238 
1239   // Size of _data array in bytes.  (Excludes header and extra_data fields.)
1240   int _data_size;
1241 
1242   // Beginning of the data entries
1243   intptr_t _data[1];
1244 
1245   // Helper for size computation
1246   static int compute_data_size(BytecodeStream* stream);
1247   static int bytecode_cell_count(Bytecodes::Code code);
1248   enum { no_profile_data = -1, variable_cell_count = -2 };
1249 
1250   // Helper for initialization
1251   DataLayout* data_layout_at(int data_index) {
1252     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
1253     return (DataLayout*) (((address)_data) + data_index);
1254   }
1255 
1256   // Initialize an individual data segment.  Returns the size of
1257   // the segment in bytes.
1258   int initialize_data(BytecodeStream* stream, int data_index);
1259 
1260   // Helper for data_at
1261   DataLayout* limit_data_position() {
1262     return (DataLayout*)((address)data_base() + _data_size);
1263   }
1264   bool out_of_bounds(int data_index) {
1265     return data_index >= data_size();
1266   }
1267 
1268   // Give each of the data entries a chance to perform specific
1269   // data initialization.
1270   void post_initialize(BytecodeStream* stream);
1271 
1272   // hint accessors
1273   int      hint_di() const  { return _hint_di; }
1274   void set_hint_di(int di)  {
1275     assert(!out_of_bounds(di), "hint_di out of bounds");
1276     _hint_di = di;
1277   }
1278   ProfileData* data_before(int bci) {
1279     // avoid SEGV on this edge case
1280     if (data_size() == 0)
1281       return NULL;
1282     int hint = hint_di();
1283     if (data_layout_at(hint)->bci() <= bci)
1284       return data_at(hint);
1285     return first_data();
1286   }
1287 
1288   // What is the index of the first data entry?
1289   int first_di() { return 0; }
1290 
1291   // Find or create an extra ProfileData:
1292   ProfileData* bci_to_extra_data(int bci, bool create_if_missing);
1293 
1294   // return the argument info cell
1295   ArgInfoData *arg_info();
1296 
1297 public:
1298   static int header_size() {
1299     return sizeof(methodDataOopDesc)/wordSize;
1300   }
1301 
1302   // Compute the size of a methodDataOop before it is created.
1303   static int compute_allocation_size_in_bytes(methodHandle method);
1304   static int compute_allocation_size_in_words(methodHandle method);
1305   static int compute_extra_data_count(int data_size, int empty_bc_count);
1306 
1307   // Determine if a given bytecode can have profile information.
1308   static bool bytecode_has_profile(Bytecodes::Code code) {
1309     return bytecode_cell_count(code) != no_profile_data;
1310   }
1311 
1312   // Perform initialization of a new methodDataOop
1313   void initialize(methodHandle method);
1314 
1315   // My size
1316   int object_size_in_bytes() { return _size; }
1317   int object_size() {
1318     return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord);
1319   }
1320 
1321   int      creation_mileage() const  { return _creation_mileage; }
1322   void set_creation_mileage(int x)   { _creation_mileage = x; }
1323 
1324   int invocation_count() {
1325     if (invocation_counter()->carry()) {
1326       return InvocationCounter::count_limit;
1327     }
1328     return invocation_counter()->count();
1329   }
1330   int backedge_count() {
1331     if (backedge_counter()->carry()) {
1332       return InvocationCounter::count_limit;
1333     }
1334     return backedge_counter()->count();
1335   }
1336 
1337   int invocation_count_start() {
1338     if (invocation_counter()->carry()) {
1339       return 0;
1340     }
1341     return _invocation_counter_start;
1342   }
1343 
1344   int backedge_count_start() {
1345     if (backedge_counter()->carry()) {
1346       return 0;
1347     }
1348     return _backedge_counter_start;
1349   }
1350 
1351   int invocation_count_delta() { return invocation_count() - invocation_count_start(); }
1352   int backedge_count_delta()   { return backedge_count()   - backedge_count_start();   }
1353 
1354   void reset_start_counters() {
1355     _invocation_counter_start = invocation_count();
1356     _backedge_counter_start = backedge_count();
1357   }
1358 
1359   InvocationCounter* invocation_counter()     { return &_invocation_counter; }
1360   InvocationCounter* backedge_counter()       { return &_backedge_counter;   }
1361 
1362   void set_would_profile(bool p)              { _would_profile = p;    }
1363   bool would_profile() const                  { return _would_profile; }
1364 
1365   int highest_comp_level()                    { return _highest_comp_level;      }
1366   void set_highest_comp_level(int level)      { _highest_comp_level = level;     }
1367   int highest_osr_comp_level()                { return _highest_osr_comp_level;  }
1368   void set_highest_osr_comp_level(int level)  { _highest_osr_comp_level = level; }
1369 
1370   int num_loops() const                       { return _num_loops;  }
1371   void set_num_loops(int n)                   { _num_loops = n;     }
1372   int num_blocks() const                      { return _num_blocks; }
1373   void set_num_blocks(int n)                  { _num_blocks = n;    }
1374 
1375   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
1376   static int mileage_of(methodOop m);
1377 
1378   // Support for interprocedural escape analysis, from Thomas Kotzmann.
1379   enum EscapeFlag {
1380     estimated    = 1 << 0,
1381     return_local = 1 << 1,
1382     return_allocated = 1 << 2,
1383     allocated_escapes = 1 << 3,
1384     unknown_modified = 1 << 4
1385   };
1386 
1387   intx eflags()                                  { return _eflags; }
1388   intx arg_local()                               { return _arg_local; }
1389   intx arg_stack()                               { return _arg_stack; }
1390   intx arg_returned()                            { return _arg_returned; }
1391   uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
1392                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1393                                                    return aid->arg_modified(a); }
1394 
1395   void set_eflags(intx v)                        { _eflags = v; }
1396   void set_arg_local(intx v)                     { _arg_local = v; }
1397   void set_arg_stack(intx v)                     { _arg_stack = v; }
1398   void set_arg_returned(intx v)                  { _arg_returned = v; }
1399   void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
1400                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
1401 
1402                                                    aid->set_arg_modified(a, v); }
1403 
1404   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
1405 
1406   // Location and size of data area
1407   address data_base() const {
1408     return (address) _data;
1409   }
1410   int data_size() {
1411     return _data_size;
1412   }
1413 
1414   // Accessors
1415   methodOop method() { return _method; }
1416 
1417   // Get the data at an arbitrary (sort of) data index.
1418   ProfileData* data_at(int data_index);
1419 
1420   // Walk through the data in order.
1421   ProfileData* first_data() { return data_at(first_di()); }
1422   ProfileData* next_data(ProfileData* current);
1423   bool is_valid(ProfileData* current) { return current != NULL; }
1424 
1425   // Convert a dp (data pointer) to a di (data index).
1426   int dp_to_di(address dp) {
1427     return dp - ((address)_data);
1428   }
1429 
1430   address di_to_dp(int di) {
1431     return (address)data_layout_at(di);
1432   }
1433 
1434   // bci to di/dp conversion.
1435   address bci_to_dp(int bci);
1436   int bci_to_di(int bci) {
1437     return dp_to_di(bci_to_dp(bci));
1438   }
1439 
1440   // Get the data at an arbitrary bci, or NULL if there is none.
1441   ProfileData* bci_to_data(int bci);
1442 
1443   // Same, but try to create an extra_data record if one is needed:
1444   ProfileData* allocate_bci_to_data(int bci) {
1445     ProfileData* data = bci_to_data(bci);
1446     return (data != NULL) ? data : bci_to_extra_data(bci, true);
1447   }
1448 
1449   // Add a handful of extra data records, for trap tracking.
1450   DataLayout* extra_data_base() { return limit_data_position(); }
1451   DataLayout* extra_data_limit() { return (DataLayout*)((address)this + object_size_in_bytes()); }
1452   int extra_data_size() { return (address)extra_data_limit()
1453                                - (address)extra_data_base(); }
1454   static DataLayout* next_extra(DataLayout* dp) { return (DataLayout*)((address)dp + in_bytes(DataLayout::cell_offset(0))); }
1455 
1456   // Return (uint)-1 for overflow.
1457   uint trap_count(int reason) const {
1458     assert((uint)reason < _trap_hist_limit, "oob");
1459     return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
1460   }
1461   // For loops:
1462   static uint trap_reason_limit() { return _trap_hist_limit; }
1463   static uint trap_count_limit()  { return _trap_hist_mask; }
1464   uint inc_trap_count(int reason) {
1465     // Count another trap, anywhere in this method.
1466     assert(reason >= 0, "must be single trap");
1467     if ((uint)reason < _trap_hist_limit) {
1468       uint cnt1 = 1 + _trap_hist._array[reason];
1469       if ((cnt1 & _trap_hist_mask) != 0) {  // if no counter overflow...
1470         _trap_hist._array[reason] = cnt1;
1471         return cnt1;
1472       } else {
1473         return _trap_hist_mask + (++_nof_overflow_traps);
1474       }
1475     } else {
1476       // Could not represent the count in the histogram.
1477       return (++_nof_overflow_traps);
1478     }
1479   }
1480 
1481   uint overflow_trap_count() const {
1482     return _nof_overflow_traps;
1483   }
1484   uint overflow_recompile_count() const {
1485     return _nof_overflow_recompiles;
1486   }
1487   void inc_overflow_recompile_count() {
1488     _nof_overflow_recompiles += 1;
1489   }
1490   uint decompile_count() const {
1491     return _nof_decompiles;
1492   }
1493   void inc_decompile_count() {
1494     _nof_decompiles += 1;
1495     if (decompile_count() > (uint)PerMethodRecompilationCutoff) {
1496       method()->set_not_compilable(CompLevel_full_optimization);
1497     }
1498   }
1499 
1500   // Support for code generation
1501   static ByteSize data_offset() {
1502     return byte_offset_of(methodDataOopDesc, _data[0]);
1503   }
1504 
1505   static ByteSize invocation_counter_offset() {
1506     return byte_offset_of(methodDataOopDesc, _invocation_counter);
1507   }
1508   static ByteSize backedge_counter_offset() {
1509     return byte_offset_of(methodDataOopDesc, _backedge_counter);
1510   }
1511 
1512   // GC support
1513   oop* adr_method() const { return (oop*)&_method; }
1514   bool object_is_parsable() const { return _size != 0; }
1515   void set_object_is_parsable(int object_size_in_bytes) { _size = object_size_in_bytes; }
1516 
1517 #ifndef PRODUCT
1518   // printing support for method data
1519   void print_data_on(outputStream* st);
1520 #endif
1521 
1522   // verification
1523   void verify_data_on(outputStream* st);
1524 };
1525 
1526 #endif // SHARE_VM_OOPS_METHODDATAOOP_HPP