1 /*
   2  * Copyright (c) 2000, 2014, 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/method.hpp"
  31 #include "oops/oop.hpp"
  32 #include "runtime/orderAccess.hpp"
  33 
  34 class BytecodeStream;
  35 class KlassSizeStats;
  36 
  37 // The MethodData object collects counts and other profile information
  38 // during zeroth-tier (interpretive) and first-tier execution.
  39 // The profile is used later by compilation heuristics.  Some heuristics
  40 // enable use of aggressive (or "heroic") optimizations.  An aggressive
  41 // optimization often has a down-side, a corner case that it handles
  42 // poorly, but which is thought to be rare.  The profile provides
  43 // evidence of this rarity for a given method or even BCI.  It allows
  44 // the compiler to back out of the optimization at places where it
  45 // has historically been a poor choice.  Other heuristics try to use
  46 // specific information gathered about types observed at a given site.
  47 //
  48 // All data in the profile is approximate.  It is expected to be accurate
  49 // on the whole, but the system expects occasional inaccuraces, due to
  50 // counter overflow, multiprocessor races during data collection, space
  51 // limitations, missing MDO blocks, etc.  Bad or missing data will degrade
  52 // optimization quality but will not affect correctness.  Also, each MDO
  53 // is marked with its birth-date ("creation_mileage") which can be used
  54 // to assess the quality ("maturity") of its data.
  55 //
  56 // Short (<32-bit) counters are designed to overflow to a known "saturated"
  57 // state.  Also, certain recorded per-BCI events are given one-bit counters
  58 // which overflow to a saturated state which applied to all counters at
  59 // that BCI.  In other words, there is a small lattice which approximates
  60 // the ideal of an infinite-precision counter for each event at each BCI,
  61 // and the lattice quickly "bottoms out" in a state where all counters
  62 // are taken to be indefinitely large.
  63 //
  64 // The reader will find many data races in profile gathering code, starting
  65 // with invocation counter incrementation.  None of these races harm correct
  66 // execution of the compiled code.
  67 
  68 // forward decl
  69 class ProfileData;
  70 
  71 // DataLayout
  72 //
  73 // Overlay for generic profiling data.
  74 class DataLayout VALUE_OBJ_CLASS_SPEC {
  75   friend class VMStructs;
  76 
  77 private:
  78   // Every data layout begins with a header.  This header
  79   // contains a tag, which is used to indicate the size/layout
  80   // of the data, 4 bits of flags, which can be used in any way,
  81   // 4 bits of trap history (none/one reason/many reasons),
  82   // and a bci, which is used to tie this piece of data to a
  83   // specific bci in the bytecodes.
  84   union {
  85     intptr_t _bits;
  86     struct {
  87       u1 _tag;
  88       u1 _flags;
  89       u2 _bci;
  90     } _struct;
  91   } _header;
  92 
  93   // The data layout has an arbitrary number of cells, each sized
  94   // to accomodate a pointer or an integer.
  95   intptr_t _cells[1];
  96 
  97   // Some types of data layouts need a length field.
  98   static bool needs_array_len(u1 tag);
  99 
 100 public:
 101   enum {
 102     counter_increment = 1
 103   };
 104 
 105   enum {
 106     cell_size = sizeof(intptr_t)
 107   };
 108 
 109   // Tag values
 110   enum {
 111     no_tag,
 112     bit_data_tag,
 113     counter_data_tag,
 114     jump_data_tag,
 115     receiver_type_data_tag,
 116     virtual_call_data_tag,
 117     ret_data_tag,
 118     branch_data_tag,
 119     multi_branch_data_tag,
 120     arg_info_data_tag,
 121     call_type_data_tag,
 122     virtual_call_type_data_tag,
 123     parameters_type_data_tag,
 124     speculative_trap_data_tag
 125   };
 126 
 127   enum {
 128     // The _struct._flags word is formatted as [trap_state:4 | flags:4].
 129     // The trap state breaks down further as [recompile:1 | reason:3].
 130     // This further breakdown is defined in deoptimization.cpp.
 131     // See Deoptimization::trap_state_reason for an assert that
 132     // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
 133     //
 134     // The trap_state is collected only if ProfileTraps is true.
 135     trap_bits = 1+3,  // 3: enough to distinguish [0..Reason_RECORDED_LIMIT].
 136     trap_shift = BitsPerByte - trap_bits,
 137     trap_mask = right_n_bits(trap_bits),
 138     trap_mask_in_place = (trap_mask << trap_shift),
 139     flag_limit = trap_shift,
 140     flag_mask = right_n_bits(flag_limit),
 141     first_flag = 0
 142   };
 143 
 144   // Size computation
 145   static int header_size_in_bytes() {
 146     return cell_size;
 147   }
 148   static int header_size_in_cells() {
 149     return 1;
 150   }
 151 
 152   static int compute_size_in_bytes(int cell_count) {
 153     return header_size_in_bytes() + cell_count * cell_size;
 154   }
 155 
 156   // Initialization
 157   void initialize(u1 tag, u2 bci, int cell_count);
 158 
 159   // Accessors
 160   u1 tag() {
 161     return _header._struct._tag;
 162   }
 163 
 164   // Return a few bits of trap state.  Range is [0..trap_mask].
 165   // The state tells if traps with zero, one, or many reasons have occurred.
 166   // It also tells whether zero or many recompilations have occurred.
 167   // The associated trap histogram in the MDO itself tells whether
 168   // traps are common or not.  If a BCI shows that a trap X has
 169   // occurred, and the MDO shows N occurrences of X, we make the
 170   // simplifying assumption that all N occurrences can be blamed
 171   // on that BCI.
 172   int trap_state() const {
 173     return ((_header._struct._flags >> trap_shift) & trap_mask);
 174   }
 175 
 176   void set_trap_state(int new_state) {
 177     assert(ProfileTraps, "used only under +ProfileTraps");
 178     uint old_flags = (_header._struct._flags & flag_mask);
 179     _header._struct._flags = (new_state << trap_shift) | old_flags;
 180   }
 181 
 182   u1 flags() const {
 183     return _header._struct._flags;
 184   }
 185 
 186   u2 bci() const {
 187     return _header._struct._bci;
 188   }
 189 
 190   void set_header(intptr_t value) {
 191     _header._bits = value;
 192   }
 193   intptr_t header() {
 194     return _header._bits;
 195   }
 196   void set_cell_at(int index, intptr_t value) {
 197     _cells[index] = value;
 198   }
 199   void release_set_cell_at(int index, intptr_t value) {
 200     OrderAccess::release_store_ptr(&_cells[index], value);
 201   }
 202   intptr_t cell_at(int index) const {
 203     return _cells[index];
 204   }
 205 
 206   void set_flag_at(int flag_number) {
 207     assert(flag_number < flag_limit, "oob");
 208     _header._struct._flags |= (0x1 << flag_number);
 209   }
 210   bool flag_at(int flag_number) const {
 211     assert(flag_number < flag_limit, "oob");
 212     return (_header._struct._flags & (0x1 << flag_number)) != 0;
 213   }
 214 
 215   // Low-level support for code generation.
 216   static ByteSize header_offset() {
 217     return byte_offset_of(DataLayout, _header);
 218   }
 219   static ByteSize tag_offset() {
 220     return byte_offset_of(DataLayout, _header._struct._tag);
 221   }
 222   static ByteSize flags_offset() {
 223     return byte_offset_of(DataLayout, _header._struct._flags);
 224   }
 225   static ByteSize bci_offset() {
 226     return byte_offset_of(DataLayout, _header._struct._bci);
 227   }
 228   static ByteSize cell_offset(int index) {
 229     return byte_offset_of(DataLayout, _cells) + in_ByteSize(index * cell_size);
 230   }
 231 #ifdef CC_INTERP
 232   static int cell_offset_in_bytes(int index) {
 233     return (int)offset_of(DataLayout, _cells[index]);
 234   }
 235 #endif // CC_INTERP
 236   // Return a value which, when or-ed as a byte into _flags, sets the flag.
 237   static int flag_number_to_byte_constant(int flag_number) {
 238     assert(0 <= flag_number && flag_number < flag_limit, "oob");
 239     DataLayout temp; temp.set_header(0);
 240     temp.set_flag_at(flag_number);
 241     return temp._header._struct._flags;
 242   }
 243   // Return a value which, when or-ed as a word into _header, sets the flag.
 244   static intptr_t flag_mask_to_header_mask(int byte_constant) {
 245     DataLayout temp; temp.set_header(0);
 246     temp._header._struct._flags = byte_constant;
 247     return temp._header._bits;
 248   }
 249 
 250   ProfileData* data_in();
 251 
 252   // GC support
 253   void clean_weak_klass_links(BoolObjectClosure* cl);
 254 
 255   // Redefinition support
 256   void clean_weak_method_links();
 257 };
 258 
 259 
 260 // ProfileData class hierarchy
 261 class ProfileData;
 262 class   BitData;
 263 class     CounterData;
 264 class       ReceiverTypeData;
 265 class         VirtualCallData;
 266 class           VirtualCallTypeData;
 267 class       RetData;
 268 class       CallTypeData;
 269 class   JumpData;
 270 class     BranchData;
 271 class   ArrayData;
 272 class     MultiBranchData;
 273 class     ArgInfoData;
 274 class     ParametersTypeData;
 275 class   SpeculativeTrapData;
 276 
 277 // ProfileData
 278 //
 279 // A ProfileData object is created to refer to a section of profiling
 280 // data in a structured way.
 281 class ProfileData : public ResourceObj {
 282   friend class TypeEntries;
 283   friend class ReturnTypeEntry;
 284   friend class TypeStackSlotEntries;
 285 private:
 286   enum {
 287     tab_width_one = 16,
 288     tab_width_two = 36
 289   };
 290 
 291   // This is a pointer to a section of profiling data.
 292   DataLayout* _data;
 293 
 294   char* print_data_on_helper(const MethodData* md) const;
 295 
 296 protected:
 297   DataLayout* data() { return _data; }
 298   const DataLayout* data() const { return _data; }
 299 
 300   enum {
 301     cell_size = DataLayout::cell_size
 302   };
 303 
 304 public:
 305   // How many cells are in this?
 306   virtual int cell_count() const {
 307     ShouldNotReachHere();
 308     return -1;
 309   }
 310 
 311   // Return the size of this data.
 312   int size_in_bytes() {
 313     return DataLayout::compute_size_in_bytes(cell_count());
 314   }
 315 
 316 protected:
 317   // Low-level accessors for underlying data
 318   void set_intptr_at(int index, intptr_t value) {
 319     assert(0 <= index && index < cell_count(), "oob");
 320     data()->set_cell_at(index, value);
 321   }
 322   void release_set_intptr_at(int index, intptr_t value) {
 323     assert(0 <= index && index < cell_count(), "oob");
 324     data()->release_set_cell_at(index, value);
 325   }
 326   intptr_t intptr_at(int index) const {
 327     assert(0 <= index && index < cell_count(), "oob");
 328     return data()->cell_at(index);
 329   }
 330   void set_uint_at(int index, uint value) {
 331     set_intptr_at(index, (intptr_t) value);
 332   }
 333   void release_set_uint_at(int index, uint value) {
 334     release_set_intptr_at(index, (intptr_t) value);
 335   }
 336   uint uint_at(int index) const {
 337     return (uint)intptr_at(index);
 338   }
 339   void set_int_at(int index, int value) {
 340     set_intptr_at(index, (intptr_t) value);
 341   }
 342   void release_set_int_at(int index, int value) {
 343     release_set_intptr_at(index, (intptr_t) value);
 344   }
 345   int int_at(int index) const {
 346     return (int)intptr_at(index);
 347   }
 348   int int_at_unchecked(int index) const {
 349     return (int)data()->cell_at(index);
 350   }
 351   void set_oop_at(int index, oop value) {
 352     set_intptr_at(index, cast_from_oop<intptr_t>(value));
 353   }
 354   oop oop_at(int index) const {
 355     return cast_to_oop(intptr_at(index));
 356   }
 357 
 358   void set_flag_at(int flag_number) {
 359     data()->set_flag_at(flag_number);
 360   }
 361   bool flag_at(int flag_number) const {
 362     return data()->flag_at(flag_number);
 363   }
 364 
 365   // two convenient imports for use by subclasses:
 366   static ByteSize cell_offset(int index) {
 367     return DataLayout::cell_offset(index);
 368   }
 369   static int flag_number_to_byte_constant(int flag_number) {
 370     return DataLayout::flag_number_to_byte_constant(flag_number);
 371   }
 372 
 373   ProfileData(DataLayout* data) {
 374     _data = data;
 375   }
 376 
 377 #ifdef CC_INTERP
 378   // Static low level accessors for DataLayout with ProfileData's semantics.
 379 
 380   static int cell_offset_in_bytes(int index) {
 381     return DataLayout::cell_offset_in_bytes(index);
 382   }
 383 
 384   static void increment_uint_at_no_overflow(DataLayout* layout, int index,
 385                                             int inc = DataLayout::counter_increment) {
 386     uint count = ((uint)layout->cell_at(index)) + inc;
 387     if (count == 0) return;
 388     layout->set_cell_at(index, (intptr_t) count);
 389   }
 390 
 391   static int int_at(DataLayout* layout, int index) {
 392     return (int)layout->cell_at(index);
 393   }
 394 
 395   static int uint_at(DataLayout* layout, int index) {
 396     return (uint)layout->cell_at(index);
 397   }
 398 
 399   static oop oop_at(DataLayout* layout, int index) {
 400     return cast_to_oop(layout->cell_at(index));
 401   }
 402 
 403   static void set_intptr_at(DataLayout* layout, int index, intptr_t value) {
 404     layout->set_cell_at(index, (intptr_t) value);
 405   }
 406 
 407   static void set_flag_at(DataLayout* layout, int flag_number) {
 408     layout->set_flag_at(flag_number);
 409   }
 410 #endif // CC_INTERP
 411 
 412 public:
 413   // Constructor for invalid ProfileData.
 414   ProfileData();
 415 
 416   u2 bci() const {
 417     return data()->bci();
 418   }
 419 
 420   address dp() {
 421     return (address)_data;
 422   }
 423 
 424   int trap_state() const {
 425     return data()->trap_state();
 426   }
 427   void set_trap_state(int new_state) {
 428     data()->set_trap_state(new_state);
 429   }
 430 
 431   // Type checking
 432   virtual bool is_BitData()         const { return false; }
 433   virtual bool is_CounterData()     const { return false; }
 434   virtual bool is_JumpData()        const { return false; }
 435   virtual bool is_ReceiverTypeData()const { return false; }
 436   virtual bool is_VirtualCallData() const { return false; }
 437   virtual bool is_RetData()         const { return false; }
 438   virtual bool is_BranchData()      const { return false; }
 439   virtual bool is_ArrayData()       const { return false; }
 440   virtual bool is_MultiBranchData() const { return false; }
 441   virtual bool is_ArgInfoData()     const { return false; }
 442   virtual bool is_CallTypeData()    const { return false; }
 443   virtual bool is_VirtualCallTypeData()const { return false; }
 444   virtual bool is_ParametersTypeData() const { return false; }
 445   virtual bool is_SpeculativeTrapData()const { return false; }
 446 
 447 
 448   BitData* as_BitData() const {
 449     assert(is_BitData(), "wrong type");
 450     return is_BitData()         ? (BitData*)        this : NULL;
 451   }
 452   CounterData* as_CounterData() const {
 453     assert(is_CounterData(), "wrong type");
 454     return is_CounterData()     ? (CounterData*)    this : NULL;
 455   }
 456   JumpData* as_JumpData() const {
 457     assert(is_JumpData(), "wrong type");
 458     return is_JumpData()        ? (JumpData*)       this : NULL;
 459   }
 460   ReceiverTypeData* as_ReceiverTypeData() const {
 461     assert(is_ReceiverTypeData(), "wrong type");
 462     return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
 463   }
 464   VirtualCallData* as_VirtualCallData() const {
 465     assert(is_VirtualCallData(), "wrong type");
 466     return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
 467   }
 468   RetData* as_RetData() const {
 469     assert(is_RetData(), "wrong type");
 470     return is_RetData()         ? (RetData*)        this : NULL;
 471   }
 472   BranchData* as_BranchData() const {
 473     assert(is_BranchData(), "wrong type");
 474     return is_BranchData()      ? (BranchData*)     this : NULL;
 475   }
 476   ArrayData* as_ArrayData() const {
 477     assert(is_ArrayData(), "wrong type");
 478     return is_ArrayData()       ? (ArrayData*)      this : NULL;
 479   }
 480   MultiBranchData* as_MultiBranchData() const {
 481     assert(is_MultiBranchData(), "wrong type");
 482     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
 483   }
 484   ArgInfoData* as_ArgInfoData() const {
 485     assert(is_ArgInfoData(), "wrong type");
 486     return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
 487   }
 488   CallTypeData* as_CallTypeData() const {
 489     assert(is_CallTypeData(), "wrong type");
 490     return is_CallTypeData() ? (CallTypeData*)this : NULL;
 491   }
 492   VirtualCallTypeData* as_VirtualCallTypeData() const {
 493     assert(is_VirtualCallTypeData(), "wrong type");
 494     return is_VirtualCallTypeData() ? (VirtualCallTypeData*)this : NULL;
 495   }
 496   ParametersTypeData* as_ParametersTypeData() const {
 497     assert(is_ParametersTypeData(), "wrong type");
 498     return is_ParametersTypeData() ? (ParametersTypeData*)this : NULL;
 499   }
 500   SpeculativeTrapData* as_SpeculativeTrapData() const {
 501     assert(is_SpeculativeTrapData(), "wrong type");
 502     return is_SpeculativeTrapData() ? (SpeculativeTrapData*)this : NULL;
 503   }
 504 
 505 
 506   // Subclass specific initialization
 507   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo) {}
 508 
 509   // GC support
 510   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {}
 511 
 512   // Redefinition support
 513   virtual void clean_weak_method_links() {}
 514 
 515   // CI translation: ProfileData can represent both MethodDataOop data
 516   // as well as CIMethodData data. This function is provided for translating
 517   // an oop in a ProfileData to the ci equivalent. Generally speaking,
 518   // most ProfileData don't require any translation, so we provide the null
 519   // translation here, and the required translators are in the ci subclasses.
 520   virtual void translate_from(const ProfileData* data) {}
 521 
 522   virtual void print_data_on(outputStream* st, const char* extra = NULL) const {
 523     ShouldNotReachHere();
 524   }
 525 
 526   void print_data_on(outputStream* st, const MethodData* md) const;
 527 
 528   void print_shared(outputStream* st, const char* name, const char* extra) const;
 529   void tab(outputStream* st, bool first = false) const;
 530 };
 531 
 532 // BitData
 533 //
 534 // A BitData holds a flag or two in its header.
 535 class BitData : public ProfileData {
 536 protected:
 537   enum {
 538     // null_seen:
 539     //  saw a null operand (cast/aastore/instanceof)
 540     null_seen_flag              = DataLayout::first_flag + 0
 541   };
 542   enum { bit_cell_count = 0 };  // no additional data fields needed.
 543 public:
 544   BitData(DataLayout* layout) : ProfileData(layout) {
 545   }
 546 
 547   virtual bool is_BitData() const { return true; }
 548 
 549   static int static_cell_count() {
 550     return bit_cell_count;
 551   }
 552 
 553   virtual int cell_count() const {
 554     return static_cell_count();
 555   }
 556 
 557   // Accessor
 558 
 559   // The null_seen flag bit is specially known to the interpreter.
 560   // Consulting it allows the compiler to avoid setting up null_check traps.
 561   bool null_seen()     { return flag_at(null_seen_flag); }
 562   void set_null_seen()    { set_flag_at(null_seen_flag); }
 563 
 564 
 565   // Code generation support
 566   static int null_seen_byte_constant() {
 567     return flag_number_to_byte_constant(null_seen_flag);
 568   }
 569 
 570   static ByteSize bit_data_size() {
 571     return cell_offset(bit_cell_count);
 572   }
 573 
 574 #ifdef CC_INTERP
 575   static int bit_data_size_in_bytes() {
 576     return cell_offset_in_bytes(bit_cell_count);
 577   }
 578 
 579   static void set_null_seen(DataLayout* layout) {
 580     set_flag_at(layout, null_seen_flag);
 581   }
 582 
 583   static DataLayout* advance(DataLayout* layout) {
 584     return (DataLayout*) (((address)layout) + (ssize_t)BitData::bit_data_size_in_bytes());
 585   }
 586 #endif // CC_INTERP
 587 
 588   void print_data_on(outputStream* st, const char* extra = NULL) const;
 589 };
 590 
 591 // CounterData
 592 //
 593 // A CounterData corresponds to a simple counter.
 594 class CounterData : public BitData {
 595 protected:
 596   enum {
 597     count_off,
 598     counter_cell_count
 599   };
 600 public:
 601   CounterData(DataLayout* layout) : BitData(layout) {}
 602 
 603   virtual bool is_CounterData() const { return true; }
 604 
 605   static int static_cell_count() {
 606     return counter_cell_count;
 607   }
 608 
 609   virtual int cell_count() const {
 610     return static_cell_count();
 611   }
 612 
 613   // Direct accessor
 614   uint count() const {
 615     return uint_at(count_off);
 616   }
 617 
 618   // Code generation support
 619   static ByteSize count_offset() {
 620     return cell_offset(count_off);
 621   }
 622   static ByteSize counter_data_size() {
 623     return cell_offset(counter_cell_count);
 624   }
 625 
 626   void set_count(uint count) {
 627     set_uint_at(count_off, count);
 628   }
 629 
 630 #ifdef CC_INTERP
 631   static int counter_data_size_in_bytes() {
 632     return cell_offset_in_bytes(counter_cell_count);
 633   }
 634 
 635   static void increment_count_no_overflow(DataLayout* layout) {
 636     increment_uint_at_no_overflow(layout, count_off);
 637   }
 638 
 639   // Support counter decrementation at checkcast / subtype check failed.
 640   static void decrement_count(DataLayout* layout) {
 641     increment_uint_at_no_overflow(layout, count_off, -1);
 642   }
 643 
 644   static DataLayout* advance(DataLayout* layout) {
 645     return (DataLayout*) (((address)layout) + (ssize_t)CounterData::counter_data_size_in_bytes());
 646   }
 647 #endif // CC_INTERP
 648 
 649   void print_data_on(outputStream* st, const char* extra = NULL) const;
 650 };
 651 
 652 // JumpData
 653 //
 654 // A JumpData is used to access profiling information for a direct
 655 // branch.  It is a counter, used for counting the number of branches,
 656 // plus a data displacement, used for realigning the data pointer to
 657 // the corresponding target bci.
 658 class JumpData : public ProfileData {
 659 protected:
 660   enum {
 661     taken_off_set,
 662     displacement_off_set,
 663     jump_cell_count
 664   };
 665 
 666   void set_displacement(int displacement) {
 667     set_int_at(displacement_off_set, displacement);
 668   }
 669 
 670 public:
 671   JumpData(DataLayout* layout) : ProfileData(layout) {
 672     assert(layout->tag() == DataLayout::jump_data_tag ||
 673       layout->tag() == DataLayout::branch_data_tag, "wrong type");
 674   }
 675 
 676   virtual bool is_JumpData() const { return true; }
 677 
 678   static int static_cell_count() {
 679     return jump_cell_count;
 680   }
 681 
 682   virtual int cell_count() const {
 683     return static_cell_count();
 684   }
 685 
 686   // Direct accessor
 687   uint taken() const {
 688     return uint_at(taken_off_set);
 689   }
 690 
 691   void set_taken(uint cnt) {
 692     set_uint_at(taken_off_set, cnt);
 693   }
 694 
 695   // Saturating counter
 696   uint inc_taken() {
 697     uint cnt = taken() + 1;
 698     // Did we wrap? Will compiler screw us??
 699     if (cnt == 0) cnt--;
 700     set_uint_at(taken_off_set, cnt);
 701     return cnt;
 702   }
 703 
 704   int displacement() const {
 705     return int_at(displacement_off_set);
 706   }
 707 
 708   // Code generation support
 709   static ByteSize taken_offset() {
 710     return cell_offset(taken_off_set);
 711   }
 712 
 713   static ByteSize displacement_offset() {
 714     return cell_offset(displacement_off_set);
 715   }
 716 
 717 #ifdef CC_INTERP
 718   static void increment_taken_count_no_overflow(DataLayout* layout) {
 719     increment_uint_at_no_overflow(layout, taken_off_set);
 720   }
 721 
 722   static DataLayout* advance_taken(DataLayout* layout) {
 723     return (DataLayout*) (((address)layout) + (ssize_t)int_at(layout, displacement_off_set));
 724   }
 725 
 726   static uint taken_count(DataLayout* layout) {
 727     return (uint) uint_at(layout, taken_off_set);
 728   }
 729 #endif // CC_INTERP
 730 
 731   // Specific initialization.
 732   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 733 
 734   void print_data_on(outputStream* st, const char* extra = NULL) const;
 735 };
 736 
 737 // Entries in a ProfileData object to record types: it can either be
 738 // none (no profile), unknown (conflicting profile data) or a klass if
 739 // a single one is seen. Whether a null reference was seen is also
 740 // recorded. No counter is associated with the type and a single type
 741 // is tracked (unlike VirtualCallData).
 742 class TypeEntries {
 743 
 744 public:
 745 
 746   // A single cell is used to record information for a type:
 747   // - the cell is initialized to 0
 748   // - when a type is discovered it is stored in the cell
 749   // - bit zero of the cell is used to record whether a null reference
 750   // was encountered or not
 751   // - bit 1 is set to record a conflict in the type information
 752 
 753   enum {
 754     null_seen = 1,
 755     type_mask = ~null_seen,
 756     type_unknown = 2,
 757     status_bits = null_seen | type_unknown,
 758     type_klass_mask = ~status_bits
 759   };
 760 
 761   // what to initialize a cell to
 762   static intptr_t type_none() {
 763     return 0;
 764   }
 765 
 766   // null seen = bit 0 set?
 767   static bool was_null_seen(intptr_t v) {
 768     return (v & null_seen) != 0;
 769   }
 770 
 771   // conflicting type information = bit 1 set?
 772   static bool is_type_unknown(intptr_t v) {
 773     return (v & type_unknown) != 0;
 774   }
 775 
 776   // not type information yet = all bits cleared, ignoring bit 0?
 777   static bool is_type_none(intptr_t v) {
 778     return (v & type_mask) == 0;
 779   }
 780 
 781   // recorded type: cell without bit 0 and 1
 782   static intptr_t klass_part(intptr_t v) {
 783     intptr_t r = v & type_klass_mask;
 784     return r;
 785   }
 786 
 787   // type recorded
 788   static Klass* valid_klass(intptr_t k) {
 789     if (!is_type_none(k) &&
 790         !is_type_unknown(k)) {
 791       Klass* res = (Klass*)klass_part(k);
 792       assert(res != NULL, "invalid");
 793       return res;
 794     } else {
 795       return NULL;
 796     }
 797   }
 798 
 799   static intptr_t with_status(intptr_t k, intptr_t in) {
 800     return k | (in & status_bits);
 801   }
 802 
 803   static intptr_t with_status(Klass* k, intptr_t in) {
 804     return with_status((intptr_t)k, in);
 805   }
 806 
 807   static void print_klass(outputStream* st, intptr_t k);
 808 
 809   // GC support
 810   static bool is_loader_alive(BoolObjectClosure* is_alive_cl, intptr_t p);
 811 
 812 protected:
 813   // ProfileData object these entries are part of
 814   ProfileData* _pd;
 815   // offset within the ProfileData object where the entries start
 816   const int _base_off;
 817 
 818   TypeEntries(int base_off)
 819     : _base_off(base_off), _pd(NULL) {}
 820 
 821   void set_intptr_at(int index, intptr_t value) {
 822     _pd->set_intptr_at(index, value);
 823   }
 824 
 825   intptr_t intptr_at(int index) const {
 826     return _pd->intptr_at(index);
 827   }
 828 
 829 public:
 830   void set_profile_data(ProfileData* pd) {
 831     _pd = pd;
 832   }
 833 };
 834 
 835 // Type entries used for arguments passed at a call and parameters on
 836 // method entry. 2 cells per entry: one for the type encoded as in
 837 // TypeEntries and one initialized with the stack slot where the
 838 // profiled object is to be found so that the interpreter can locate
 839 // it quickly.
 840 class TypeStackSlotEntries : public TypeEntries {
 841 
 842 private:
 843   enum {
 844     stack_slot_entry,
 845     type_entry,
 846     per_arg_cell_count
 847   };
 848 
 849   // offset of cell for stack slot for entry i within ProfileData object
 850   int stack_slot_offset(int i) const {
 851     return _base_off + stack_slot_local_offset(i);
 852   }
 853 
 854   const int _number_of_entries;
 855 
 856   // offset of cell for type for entry i within ProfileData object
 857   int type_offset_in_cells(int i) const {
 858     return _base_off + type_local_offset(i);
 859   }
 860 
 861 public:
 862 
 863   TypeStackSlotEntries(int base_off, int nb_entries)
 864     : TypeEntries(base_off), _number_of_entries(nb_entries) {}
 865 
 866   static int compute_cell_count(Symbol* signature, bool include_receiver, int max);
 867 
 868   void post_initialize(Symbol* signature, bool has_receiver, bool include_receiver);
 869 
 870   int number_of_entries() const { return _number_of_entries; }
 871 
 872   // offset of cell for stack slot for entry i within this block of cells for a TypeStackSlotEntries
 873   static int stack_slot_local_offset(int i) {
 874     return i * per_arg_cell_count + stack_slot_entry;
 875   }
 876 
 877   // offset of cell for type for entry i within this block of cells for a TypeStackSlotEntries
 878   static int type_local_offset(int i) {
 879     return i * per_arg_cell_count + type_entry;
 880   }
 881 
 882   // stack slot for entry i
 883   uint stack_slot(int i) const {
 884     assert(i >= 0 && i < _number_of_entries, "oob");
 885     return _pd->uint_at(stack_slot_offset(i));
 886   }
 887 
 888   // set stack slot for entry i
 889   void set_stack_slot(int i, uint num) {
 890     assert(i >= 0 && i < _number_of_entries, "oob");
 891     _pd->set_uint_at(stack_slot_offset(i), num);
 892   }
 893 
 894   // type for entry i
 895   intptr_t type(int i) const {
 896     assert(i >= 0 && i < _number_of_entries, "oob");
 897     return _pd->intptr_at(type_offset_in_cells(i));
 898   }
 899 
 900   // set type for entry i
 901   void set_type(int i, intptr_t k) {
 902     assert(i >= 0 && i < _number_of_entries, "oob");
 903     _pd->set_intptr_at(type_offset_in_cells(i), k);
 904   }
 905 
 906   static ByteSize per_arg_size() {
 907     return in_ByteSize(per_arg_cell_count * DataLayout::cell_size);
 908   }
 909 
 910   static int per_arg_count() {
 911     return per_arg_cell_count;
 912   }
 913 
 914   ByteSize type_offset(int i) const {
 915     return DataLayout::cell_offset(type_offset_in_cells(i));
 916   }
 917 
 918   // GC support
 919   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 920 
 921   void print_data_on(outputStream* st) const;
 922 };
 923 
 924 // Type entry used for return from a call. A single cell to record the
 925 // type.
 926 class ReturnTypeEntry : public TypeEntries {
 927 
 928 private:
 929   enum {
 930     cell_count = 1
 931   };
 932 
 933 public:
 934   ReturnTypeEntry(int base_off)
 935     : TypeEntries(base_off) {}
 936 
 937   void post_initialize() {
 938     set_type(type_none());
 939   }
 940 
 941   intptr_t type() const {
 942     return _pd->intptr_at(_base_off);
 943   }
 944 
 945   void set_type(intptr_t k) {
 946     _pd->set_intptr_at(_base_off, k);
 947   }
 948 
 949   static int static_cell_count() {
 950     return cell_count;
 951   }
 952 
 953   static ByteSize size() {
 954     return in_ByteSize(cell_count * DataLayout::cell_size);
 955   }
 956 
 957   ByteSize type_offset() {
 958     return DataLayout::cell_offset(_base_off);
 959   }
 960 
 961   // GC support
 962   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 963 
 964   void print_data_on(outputStream* st) const;
 965 };
 966 
 967 // Entries to collect type information at a call: contains arguments
 968 // (TypeStackSlotEntries), a return type (ReturnTypeEntry) and a
 969 // number of cells. Because the number of cells for the return type is
 970 // smaller than the number of cells for the type of an arguments, the
 971 // number of cells is used to tell how many arguments are profiled and
 972 // whether a return value is profiled. See has_arguments() and
 973 // has_return().
 974 class TypeEntriesAtCall {
 975 private:
 976   static int stack_slot_local_offset(int i) {
 977     return header_cell_count() + TypeStackSlotEntries::stack_slot_local_offset(i);
 978   }
 979 
 980   static int argument_type_local_offset(int i) {
 981     return header_cell_count() + TypeStackSlotEntries::type_local_offset(i);
 982   }
 983 
 984 public:
 985 
 986   static int header_cell_count() {
 987     return 1;
 988   }
 989 
 990   static int cell_count_local_offset() {
 991     return 0;
 992   }
 993 
 994   static int compute_cell_count(BytecodeStream* stream);
 995 
 996   static void initialize(DataLayout* dl, int base, int cell_count) {
 997     int off = base + cell_count_local_offset();
 998     dl->set_cell_at(off, cell_count - base - header_cell_count());
 999   }
1000 
1001   static bool arguments_profiling_enabled();
1002   static bool return_profiling_enabled();
1003 
1004   // Code generation support
1005   static ByteSize cell_count_offset() {
1006     return in_ByteSize(cell_count_local_offset() * DataLayout::cell_size);
1007   }
1008 
1009   static ByteSize args_data_offset() {
1010     return in_ByteSize(header_cell_count() * DataLayout::cell_size);
1011   }
1012 
1013   static ByteSize stack_slot_offset(int i) {
1014     return in_ByteSize(stack_slot_local_offset(i) * DataLayout::cell_size);
1015   }
1016 
1017   static ByteSize argument_type_offset(int i) {
1018     return in_ByteSize(argument_type_local_offset(i) * DataLayout::cell_size);
1019   }
1020 
1021   static ByteSize return_only_size() {
1022     return ReturnTypeEntry::size() + in_ByteSize(header_cell_count() * DataLayout::cell_size);
1023   }
1024 
1025 };
1026 
1027 // CallTypeData
1028 //
1029 // A CallTypeData is used to access profiling information about a non
1030 // virtual call for which we collect type information about arguments
1031 // and return value.
1032 class CallTypeData : public CounterData {
1033 private:
1034   // entries for arguments if any
1035   TypeStackSlotEntries _args;
1036   // entry for return type if any
1037   ReturnTypeEntry _ret;
1038 
1039   int cell_count_global_offset() const {
1040     return CounterData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
1041   }
1042 
1043   // number of cells not counting the header
1044   int cell_count_no_header() const {
1045     return uint_at(cell_count_global_offset());
1046   }
1047 
1048   void check_number_of_arguments(int total) {
1049     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
1050   }
1051 
1052 public:
1053   CallTypeData(DataLayout* layout) :
1054     CounterData(layout),
1055     _args(CounterData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
1056     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
1057   {
1058     assert(layout->tag() == DataLayout::call_type_data_tag, "wrong type");
1059     // Some compilers (VC++) don't want this passed in member initialization list
1060     _args.set_profile_data(this);
1061     _ret.set_profile_data(this);
1062   }
1063 
1064   const TypeStackSlotEntries* args() const {
1065     assert(has_arguments(), "no profiling of arguments");
1066     return &_args;
1067   }
1068 
1069   const ReturnTypeEntry* ret() const {
1070     assert(has_return(), "no profiling of return value");
1071     return &_ret;
1072   }
1073 
1074   virtual bool is_CallTypeData() const { return true; }
1075 
1076   static int static_cell_count() {
1077     return -1;
1078   }
1079 
1080   static int compute_cell_count(BytecodeStream* stream) {
1081     return CounterData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
1082   }
1083 
1084   static void initialize(DataLayout* dl, int cell_count) {
1085     TypeEntriesAtCall::initialize(dl, CounterData::static_cell_count(), cell_count);
1086   }
1087 
1088   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1089 
1090   virtual int cell_count() const {
1091     return CounterData::static_cell_count() +
1092       TypeEntriesAtCall::header_cell_count() +
1093       int_at_unchecked(cell_count_global_offset());
1094   }
1095 
1096   int number_of_arguments() const {
1097     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
1098   }
1099 
1100   void set_argument_type(int i, Klass* k) {
1101     assert(has_arguments(), "no arguments!");
1102     intptr_t current = _args.type(i);
1103     _args.set_type(i, TypeEntries::with_status(k, current));
1104   }
1105 
1106   void set_return_type(Klass* k) {
1107     assert(has_return(), "no return!");
1108     intptr_t current = _ret.type();
1109     _ret.set_type(TypeEntries::with_status(k, current));
1110   }
1111 
1112   // An entry for a return value takes less space than an entry for an
1113   // argument so if the number of cells exceeds the number of cells
1114   // needed for an argument, this object contains type information for
1115   // at least one argument.
1116   bool has_arguments() const {
1117     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
1118     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
1119     return res;
1120   }
1121 
1122   // An entry for a return value takes less space than an entry for an
1123   // argument, so if the remainder of the number of cells divided by
1124   // the number of cells for an argument is not null, a return value
1125   // is profiled in this object.
1126   bool has_return() const {
1127     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
1128     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
1129     return res;
1130   }
1131 
1132   // Code generation support
1133   static ByteSize args_data_offset() {
1134     return cell_offset(CounterData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
1135   }
1136 
1137   ByteSize argument_type_offset(int i) {
1138     return _args.type_offset(i);
1139   }
1140 
1141   ByteSize return_type_offset() {
1142     return _ret.type_offset();
1143   }
1144 
1145   // GC support
1146   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1147     if (has_arguments()) {
1148       _args.clean_weak_klass_links(is_alive_closure);
1149     }
1150     if (has_return()) {
1151       _ret.clean_weak_klass_links(is_alive_closure);
1152     }
1153   }
1154 
1155   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1156 };
1157 
1158 // ReceiverTypeData
1159 //
1160 // A ReceiverTypeData is used to access profiling information about a
1161 // dynamic type check.  It consists of a counter which counts the total times
1162 // that the check is reached, and a series of (Klass*, count) pairs
1163 // which are used to store a type profile for the receiver of the check.
1164 class ReceiverTypeData : public CounterData {
1165 protected:
1166   enum {
1167     receiver0_offset = counter_cell_count,
1168     count0_offset,
1169     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
1170   };
1171 
1172 public:
1173   ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
1174     assert(layout->tag() == DataLayout::receiver_type_data_tag ||
1175            layout->tag() == DataLayout::virtual_call_data_tag ||
1176            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1177   }
1178 
1179   virtual bool is_ReceiverTypeData() const { return true; }
1180 
1181   static int static_cell_count() {
1182     return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
1183   }
1184 
1185   virtual int cell_count() const {
1186     return static_cell_count();
1187   }
1188 
1189   // Direct accessors
1190   static uint row_limit() {
1191     return TypeProfileWidth;
1192   }
1193   static int receiver_cell_index(uint row) {
1194     return receiver0_offset + row * receiver_type_row_cell_count;
1195   }
1196   static int receiver_count_cell_index(uint row) {
1197     return count0_offset + row * receiver_type_row_cell_count;
1198   }
1199 
1200   Klass* receiver(uint row) const {
1201     assert(row < row_limit(), "oob");
1202 
1203     Klass* recv = (Klass*)intptr_at(receiver_cell_index(row));
1204     assert(recv == NULL || recv->is_klass(), "wrong type");
1205     return recv;
1206   }
1207 
1208   void set_receiver(uint row, Klass* k) {
1209     assert((uint)row < row_limit(), "oob");
1210     set_intptr_at(receiver_cell_index(row), (uintptr_t)k);
1211   }
1212 
1213   uint receiver_count(uint row) const {
1214     assert(row < row_limit(), "oob");
1215     return uint_at(receiver_count_cell_index(row));
1216   }
1217 
1218   void set_receiver_count(uint row, uint count) {
1219     assert(row < row_limit(), "oob");
1220     set_uint_at(receiver_count_cell_index(row), count);
1221   }
1222 
1223   void clear_row(uint row) {
1224     assert(row < row_limit(), "oob");
1225     // Clear total count - indicator of polymorphic call site.
1226     // The site may look like as monomorphic after that but
1227     // it allow to have more accurate profiling information because
1228     // there was execution phase change since klasses were unloaded.
1229     // If the site is still polymorphic then MDO will be updated
1230     // to reflect it. But it could be the case that the site becomes
1231     // only bimorphic. Then keeping total count not 0 will be wrong.
1232     // Even if we use monomorphic (when it is not) for compilation
1233     // we will only have trap, deoptimization and recompile again
1234     // with updated MDO after executing method in Interpreter.
1235     // An additional receiver will be recorded in the cleaned row
1236     // during next call execution.
1237     //
1238     // Note: our profiling logic works with empty rows in any slot.
1239     // We do sorting a profiling info (ciCallProfile) for compilation.
1240     //
1241     set_count(0);
1242     set_receiver(row, NULL);
1243     set_receiver_count(row, 0);
1244   }
1245 
1246   // Code generation support
1247   static ByteSize receiver_offset(uint row) {
1248     return cell_offset(receiver_cell_index(row));
1249   }
1250   static ByteSize receiver_count_offset(uint row) {
1251     return cell_offset(receiver_count_cell_index(row));
1252   }
1253   static ByteSize receiver_type_data_size() {
1254     return cell_offset(static_cell_count());
1255   }
1256 
1257   // GC support
1258   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
1259 
1260 #ifdef CC_INTERP
1261   static int receiver_type_data_size_in_bytes() {
1262     return cell_offset_in_bytes(static_cell_count());
1263   }
1264 
1265   static Klass *receiver_unchecked(DataLayout* layout, uint row) {
1266     Klass* recv = (Klass*)layout->cell_at(receiver_cell_index(row));
1267     return recv;
1268   }
1269 
1270   static void increment_receiver_count_no_overflow(DataLayout* layout, Klass *rcvr) {
1271     const int num_rows = row_limit();
1272     // Receiver already exists?
1273     for (int row = 0; row < num_rows; row++) {
1274       if (receiver_unchecked(layout, row) == rcvr) {
1275         increment_uint_at_no_overflow(layout, receiver_count_cell_index(row));
1276         return;
1277       }
1278     }
1279     // New receiver, find a free slot.
1280     for (int row = 0; row < num_rows; row++) {
1281       if (receiver_unchecked(layout, row) == NULL) {
1282         set_intptr_at(layout, receiver_cell_index(row), (intptr_t)rcvr);
1283         increment_uint_at_no_overflow(layout, receiver_count_cell_index(row));
1284         return;
1285       }
1286     }
1287     // Receiver did not match any saved receiver and there is no empty row for it.
1288     // Increment total counter to indicate polymorphic case.
1289     increment_count_no_overflow(layout);
1290   }
1291 
1292   static DataLayout* advance(DataLayout* layout) {
1293     return (DataLayout*) (((address)layout) + (ssize_t)ReceiverTypeData::receiver_type_data_size_in_bytes());
1294   }
1295 #endif // CC_INTERP
1296 
1297   void print_receiver_data_on(outputStream* st) const;
1298   void print_data_on(outputStream* st, const char* extra = NULL) const;
1299 };
1300 
1301 // VirtualCallData
1302 //
1303 // A VirtualCallData is used to access profiling information about a
1304 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
1305 class VirtualCallData : public ReceiverTypeData {
1306 public:
1307   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
1308     assert(layout->tag() == DataLayout::virtual_call_data_tag ||
1309            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1310   }
1311 
1312   virtual bool is_VirtualCallData() const { return true; }
1313 
1314   static int static_cell_count() {
1315     // At this point we could add more profile state, e.g., for arguments.
1316     // But for now it's the same size as the base record type.
1317     return ReceiverTypeData::static_cell_count();
1318   }
1319 
1320   virtual int cell_count() const {
1321     return static_cell_count();
1322   }
1323 
1324   // Direct accessors
1325   static ByteSize virtual_call_data_size() {
1326     return cell_offset(static_cell_count());
1327   }
1328 
1329 #ifdef CC_INTERP
1330   static int virtual_call_data_size_in_bytes() {
1331     return cell_offset_in_bytes(static_cell_count());
1332   }
1333 
1334   static DataLayout* advance(DataLayout* layout) {
1335     return (DataLayout*) (((address)layout) + (ssize_t)VirtualCallData::virtual_call_data_size_in_bytes());
1336   }
1337 #endif // CC_INTERP
1338 
1339   void print_data_on(outputStream* st, const char* extra = NULL) const;
1340 };
1341 
1342 // VirtualCallTypeData
1343 //
1344 // A VirtualCallTypeData is used to access profiling information about
1345 // a virtual call for which we collect type information about
1346 // arguments and return value.
1347 class VirtualCallTypeData : public VirtualCallData {
1348 private:
1349   // entries for arguments if any
1350   TypeStackSlotEntries _args;
1351   // entry for return type if any
1352   ReturnTypeEntry _ret;
1353 
1354   int cell_count_global_offset() const {
1355     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
1356   }
1357 
1358   // number of cells not counting the header
1359   int cell_count_no_header() const {
1360     return uint_at(cell_count_global_offset());
1361   }
1362 
1363   void check_number_of_arguments(int total) {
1364     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
1365   }
1366 
1367 public:
1368   VirtualCallTypeData(DataLayout* layout) :
1369     VirtualCallData(layout),
1370     _args(VirtualCallData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
1371     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
1372   {
1373     assert(layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1374     // Some compilers (VC++) don't want this passed in member initialization list
1375     _args.set_profile_data(this);
1376     _ret.set_profile_data(this);
1377   }
1378 
1379   const TypeStackSlotEntries* args() const {
1380     assert(has_arguments(), "no profiling of arguments");
1381     return &_args;
1382   }
1383 
1384   const ReturnTypeEntry* ret() const {
1385     assert(has_return(), "no profiling of return value");
1386     return &_ret;
1387   }
1388 
1389   virtual bool is_VirtualCallTypeData() const { return true; }
1390 
1391   static int static_cell_count() {
1392     return -1;
1393   }
1394 
1395   static int compute_cell_count(BytecodeStream* stream) {
1396     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
1397   }
1398 
1399   static void initialize(DataLayout* dl, int cell_count) {
1400     TypeEntriesAtCall::initialize(dl, VirtualCallData::static_cell_count(), cell_count);
1401   }
1402 
1403   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1404 
1405   virtual int cell_count() const {
1406     return VirtualCallData::static_cell_count() +
1407       TypeEntriesAtCall::header_cell_count() +
1408       int_at_unchecked(cell_count_global_offset());
1409   }
1410 
1411   int number_of_arguments() const {
1412     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
1413   }
1414 
1415   void set_argument_type(int i, Klass* k) {
1416     assert(has_arguments(), "no arguments!");
1417     intptr_t current = _args.type(i);
1418     _args.set_type(i, TypeEntries::with_status(k, current));
1419   }
1420 
1421   void set_return_type(Klass* k) {
1422     assert(has_return(), "no return!");
1423     intptr_t current = _ret.type();
1424     _ret.set_type(TypeEntries::with_status(k, current));
1425   }
1426 
1427   // An entry for a return value takes less space than an entry for an
1428   // argument, so if the remainder of the number of cells divided by
1429   // the number of cells for an argument is not null, a return value
1430   // is profiled in this object.
1431   bool has_return() const {
1432     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
1433     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
1434     return res;
1435   }
1436 
1437   // An entry for a return value takes less space than an entry for an
1438   // argument so if the number of cells exceeds the number of cells
1439   // needed for an argument, this object contains type information for
1440   // at least one argument.
1441   bool has_arguments() const {
1442     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
1443     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
1444     return res;
1445   }
1446 
1447   // Code generation support
1448   static ByteSize args_data_offset() {
1449     return cell_offset(VirtualCallData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
1450   }
1451 
1452   ByteSize argument_type_offset(int i) {
1453     return _args.type_offset(i);
1454   }
1455 
1456   ByteSize return_type_offset() {
1457     return _ret.type_offset();
1458   }
1459 
1460   // GC support
1461   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1462     ReceiverTypeData::clean_weak_klass_links(is_alive_closure);
1463     if (has_arguments()) {
1464       _args.clean_weak_klass_links(is_alive_closure);
1465     }
1466     if (has_return()) {
1467       _ret.clean_weak_klass_links(is_alive_closure);
1468     }
1469   }
1470 
1471   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1472 };
1473 
1474 // RetData
1475 //
1476 // A RetData is used to access profiling information for a ret bytecode.
1477 // It is composed of a count of the number of times that the ret has
1478 // been executed, followed by a series of triples of the form
1479 // (bci, count, di) which count the number of times that some bci was the
1480 // target of the ret and cache a corresponding data displacement.
1481 class RetData : public CounterData {
1482 protected:
1483   enum {
1484     bci0_offset = counter_cell_count,
1485     count0_offset,
1486     displacement0_offset,
1487     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
1488   };
1489 
1490   void set_bci(uint row, int bci) {
1491     assert((uint)row < row_limit(), "oob");
1492     set_int_at(bci0_offset + row * ret_row_cell_count, bci);
1493   }
1494   void release_set_bci(uint row, int bci) {
1495     assert((uint)row < row_limit(), "oob");
1496     // 'release' when setting the bci acts as a valid flag for other
1497     // threads wrt bci_count and bci_displacement.
1498     release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
1499   }
1500   void set_bci_count(uint row, uint count) {
1501     assert((uint)row < row_limit(), "oob");
1502     set_uint_at(count0_offset + row * ret_row_cell_count, count);
1503   }
1504   void set_bci_displacement(uint row, int disp) {
1505     set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
1506   }
1507 
1508 public:
1509   RetData(DataLayout* layout) : CounterData(layout) {
1510     assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
1511   }
1512 
1513   virtual bool is_RetData() const { return true; }
1514 
1515   enum {
1516     no_bci = -1 // value of bci when bci1/2 are not in use.
1517   };
1518 
1519   static int static_cell_count() {
1520     return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
1521   }
1522 
1523   virtual int cell_count() const {
1524     return static_cell_count();
1525   }
1526 
1527   static uint row_limit() {
1528     return BciProfileWidth;
1529   }
1530   static int bci_cell_index(uint row) {
1531     return bci0_offset + row * ret_row_cell_count;
1532   }
1533   static int bci_count_cell_index(uint row) {
1534     return count0_offset + row * ret_row_cell_count;
1535   }
1536   static int bci_displacement_cell_index(uint row) {
1537     return displacement0_offset + row * ret_row_cell_count;
1538   }
1539 
1540   // Direct accessors
1541   int bci(uint row) const {
1542     return int_at(bci_cell_index(row));
1543   }
1544   uint bci_count(uint row) const {
1545     return uint_at(bci_count_cell_index(row));
1546   }
1547   int bci_displacement(uint row) const {
1548     return int_at(bci_displacement_cell_index(row));
1549   }
1550 
1551   // Interpreter Runtime support
1552   address fixup_ret(int return_bci, MethodData* mdo);
1553 
1554   // Code generation support
1555   static ByteSize bci_offset(uint row) {
1556     return cell_offset(bci_cell_index(row));
1557   }
1558   static ByteSize bci_count_offset(uint row) {
1559     return cell_offset(bci_count_cell_index(row));
1560   }
1561   static ByteSize bci_displacement_offset(uint row) {
1562     return cell_offset(bci_displacement_cell_index(row));
1563   }
1564 
1565 #ifdef CC_INTERP
1566   static DataLayout* advance(MethodData *md, int bci);
1567 #endif // CC_INTERP
1568 
1569   // Specific initialization.
1570   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1571 
1572   void print_data_on(outputStream* st, const char* extra = NULL) const;
1573 };
1574 
1575 // BranchData
1576 //
1577 // A BranchData is used to access profiling data for a two-way branch.
1578 // It consists of taken and not_taken counts as well as a data displacement
1579 // for the taken case.
1580 class BranchData : public JumpData {
1581 protected:
1582   enum {
1583     not_taken_off_set = jump_cell_count,
1584     branch_cell_count
1585   };
1586 
1587   void set_displacement(int displacement) {
1588     set_int_at(displacement_off_set, displacement);
1589   }
1590 
1591 public:
1592   BranchData(DataLayout* layout) : JumpData(layout) {
1593     assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
1594   }
1595 
1596   virtual bool is_BranchData() const { return true; }
1597 
1598   static int static_cell_count() {
1599     return branch_cell_count;
1600   }
1601 
1602   virtual int cell_count() const {
1603     return static_cell_count();
1604   }
1605 
1606   // Direct accessor
1607   uint not_taken() const {
1608     return uint_at(not_taken_off_set);
1609   }
1610 
1611   void set_not_taken(uint cnt) {
1612     set_uint_at(not_taken_off_set, cnt);
1613   }
1614 
1615   uint inc_not_taken() {
1616     uint cnt = not_taken() + 1;
1617     // Did we wrap? Will compiler screw us??
1618     if (cnt == 0) cnt--;
1619     set_uint_at(not_taken_off_set, cnt);
1620     return cnt;
1621   }
1622 
1623   // Code generation support
1624   static ByteSize not_taken_offset() {
1625     return cell_offset(not_taken_off_set);
1626   }
1627   static ByteSize branch_data_size() {
1628     return cell_offset(branch_cell_count);
1629   }
1630 
1631 #ifdef CC_INTERP
1632   static int branch_data_size_in_bytes() {
1633     return cell_offset_in_bytes(branch_cell_count);
1634   }
1635 
1636   static void increment_not_taken_count_no_overflow(DataLayout* layout) {
1637     increment_uint_at_no_overflow(layout, not_taken_off_set);
1638   }
1639 
1640   static DataLayout* advance_not_taken(DataLayout* layout) {
1641     return (DataLayout*) (((address)layout) + (ssize_t)BranchData::branch_data_size_in_bytes());
1642   }
1643 #endif // CC_INTERP
1644 
1645   // Specific initialization.
1646   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1647 
1648   void print_data_on(outputStream* st, const char* extra = NULL) const;
1649 };
1650 
1651 // ArrayData
1652 //
1653 // A ArrayData is a base class for accessing profiling data which does
1654 // not have a statically known size.  It consists of an array length
1655 // and an array start.
1656 class ArrayData : public ProfileData {
1657 protected:
1658   friend class DataLayout;
1659 
1660   enum {
1661     array_len_off_set,
1662     array_start_off_set
1663   };
1664 
1665   uint array_uint_at(int index) const {
1666     int aindex = index + array_start_off_set;
1667     return uint_at(aindex);
1668   }
1669   int array_int_at(int index) const {
1670     int aindex = index + array_start_off_set;
1671     return int_at(aindex);
1672   }
1673   oop array_oop_at(int index) const {
1674     int aindex = index + array_start_off_set;
1675     return oop_at(aindex);
1676   }
1677   void array_set_int_at(int index, int value) {
1678     int aindex = index + array_start_off_set;
1679     set_int_at(aindex, value);
1680   }
1681 
1682 #ifdef CC_INTERP
1683   // Static low level accessors for DataLayout with ArrayData's semantics.
1684 
1685   static void increment_array_uint_at_no_overflow(DataLayout* layout, int index) {
1686     int aindex = index + array_start_off_set;
1687     increment_uint_at_no_overflow(layout, aindex);
1688   }
1689 
1690   static int array_int_at(DataLayout* layout, int index) {
1691     int aindex = index + array_start_off_set;
1692     return int_at(layout, aindex);
1693   }
1694 #endif // CC_INTERP
1695 
1696   // Code generation support for subclasses.
1697   static ByteSize array_element_offset(int index) {
1698     return cell_offset(array_start_off_set + index);
1699   }
1700 
1701 public:
1702   ArrayData(DataLayout* layout) : ProfileData(layout) {}
1703 
1704   virtual bool is_ArrayData() const { return true; }
1705 
1706   static int static_cell_count() {
1707     return -1;
1708   }
1709 
1710   int array_len() const {
1711     return int_at_unchecked(array_len_off_set);
1712   }
1713 
1714   virtual int cell_count() const {
1715     return array_len() + 1;
1716   }
1717 
1718   // Code generation support
1719   static ByteSize array_len_offset() {
1720     return cell_offset(array_len_off_set);
1721   }
1722   static ByteSize array_start_offset() {
1723     return cell_offset(array_start_off_set);
1724   }
1725 };
1726 
1727 // MultiBranchData
1728 //
1729 // A MultiBranchData is used to access profiling information for
1730 // a multi-way branch (*switch bytecodes).  It consists of a series
1731 // of (count, displacement) pairs, which count the number of times each
1732 // case was taken and specify the data displacment for each branch target.
1733 class MultiBranchData : public ArrayData {
1734 protected:
1735   enum {
1736     default_count_off_set,
1737     default_disaplacement_off_set,
1738     case_array_start
1739   };
1740   enum {
1741     relative_count_off_set,
1742     relative_displacement_off_set,
1743     per_case_cell_count
1744   };
1745 
1746   void set_default_displacement(int displacement) {
1747     array_set_int_at(default_disaplacement_off_set, displacement);
1748   }
1749   void set_displacement_at(int index, int displacement) {
1750     array_set_int_at(case_array_start +
1751                      index * per_case_cell_count +
1752                      relative_displacement_off_set,
1753                      displacement);
1754   }
1755 
1756 public:
1757   MultiBranchData(DataLayout* layout) : ArrayData(layout) {
1758     assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
1759   }
1760 
1761   virtual bool is_MultiBranchData() const { return true; }
1762 
1763   static int compute_cell_count(BytecodeStream* stream);
1764 
1765   int number_of_cases() const {
1766     int alen = array_len() - 2; // get rid of default case here.
1767     assert(alen % per_case_cell_count == 0, "must be even");
1768     return (alen / per_case_cell_count);
1769   }
1770 
1771   uint default_count() const {
1772     return array_uint_at(default_count_off_set);
1773   }
1774   int default_displacement() const {
1775     return array_int_at(default_disaplacement_off_set);
1776   }
1777 
1778   uint count_at(int index) const {
1779     return array_uint_at(case_array_start +
1780                          index * per_case_cell_count +
1781                          relative_count_off_set);
1782   }
1783   int displacement_at(int index) const {
1784     return array_int_at(case_array_start +
1785                         index * per_case_cell_count +
1786                         relative_displacement_off_set);
1787   }
1788 
1789   // Code generation support
1790   static ByteSize default_count_offset() {
1791     return array_element_offset(default_count_off_set);
1792   }
1793   static ByteSize default_displacement_offset() {
1794     return array_element_offset(default_disaplacement_off_set);
1795   }
1796   static ByteSize case_count_offset(int index) {
1797     return case_array_offset() +
1798            (per_case_size() * index) +
1799            relative_count_offset();
1800   }
1801   static ByteSize case_array_offset() {
1802     return array_element_offset(case_array_start);
1803   }
1804   static ByteSize per_case_size() {
1805     return in_ByteSize(per_case_cell_count) * cell_size;
1806   }
1807   static ByteSize relative_count_offset() {
1808     return in_ByteSize(relative_count_off_set) * cell_size;
1809   }
1810   static ByteSize relative_displacement_offset() {
1811     return in_ByteSize(relative_displacement_off_set) * cell_size;
1812   }
1813 
1814 #ifdef CC_INTERP
1815   static void increment_count_no_overflow(DataLayout* layout, int index) {
1816     if (index == -1) {
1817       increment_array_uint_at_no_overflow(layout, default_count_off_set);
1818     } else {
1819       increment_array_uint_at_no_overflow(layout, case_array_start +
1820                                                   index * per_case_cell_count +
1821                                                   relative_count_off_set);
1822     }
1823   }
1824 
1825   static DataLayout* advance(DataLayout* layout, int index) {
1826     if (index == -1) {
1827       return (DataLayout*) (((address)layout) + (ssize_t)array_int_at(layout, default_disaplacement_off_set));
1828     } else {
1829       return (DataLayout*) (((address)layout) + (ssize_t)array_int_at(layout, case_array_start +
1830                                                                               index * per_case_cell_count +
1831                                                                               relative_displacement_off_set));
1832     }
1833   }
1834 #endif // CC_INTERP
1835 
1836   // Specific initialization.
1837   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1838 
1839   void print_data_on(outputStream* st, const char* extra = NULL) const;
1840 };
1841 
1842 class ArgInfoData : public ArrayData {
1843 
1844 public:
1845   ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1846     assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1847   }
1848 
1849   virtual bool is_ArgInfoData() const { return true; }
1850 
1851 
1852   int number_of_args() const {
1853     return array_len();
1854   }
1855 
1856   uint arg_modified(int arg) const {
1857     return array_uint_at(arg);
1858   }
1859 
1860   void set_arg_modified(int arg, uint val) {
1861     array_set_int_at(arg, val);
1862   }
1863 
1864   void print_data_on(outputStream* st, const char* extra = NULL) const;
1865 };
1866 
1867 // ParametersTypeData
1868 //
1869 // A ParametersTypeData is used to access profiling information about
1870 // types of parameters to a method
1871 class ParametersTypeData : public ArrayData {
1872 
1873 private:
1874   TypeStackSlotEntries _parameters;
1875 
1876   static int stack_slot_local_offset(int i) {
1877     assert_profiling_enabled();
1878     return array_start_off_set + TypeStackSlotEntries::stack_slot_local_offset(i);
1879   }
1880 
1881   static int type_local_offset(int i) {
1882     assert_profiling_enabled();
1883     return array_start_off_set + TypeStackSlotEntries::type_local_offset(i);
1884   }
1885 
1886   static bool profiling_enabled();
1887   static void assert_profiling_enabled() {
1888     assert(profiling_enabled(), "method parameters profiling should be on");
1889   }
1890 
1891 public:
1892   ParametersTypeData(DataLayout* layout) : ArrayData(layout), _parameters(1, number_of_parameters()) {
1893     assert(layout->tag() == DataLayout::parameters_type_data_tag, "wrong type");
1894     // Some compilers (VC++) don't want this passed in member initialization list
1895     _parameters.set_profile_data(this);
1896   }
1897 
1898   static int compute_cell_count(Method* m);
1899 
1900   virtual bool is_ParametersTypeData() const { return true; }
1901 
1902   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1903 
1904   int number_of_parameters() const {
1905     return array_len() / TypeStackSlotEntries::per_arg_count();
1906   }
1907 
1908   const TypeStackSlotEntries* parameters() const { return &_parameters; }
1909 
1910   uint stack_slot(int i) const {
1911     return _parameters.stack_slot(i);
1912   }
1913 
1914   void set_type(int i, Klass* k) {
1915     intptr_t current = _parameters.type(i);
1916     _parameters.set_type(i, TypeEntries::with_status((intptr_t)k, current));
1917   }
1918 
1919   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1920     _parameters.clean_weak_klass_links(is_alive_closure);
1921   }
1922 
1923   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1924 
1925   static ByteSize stack_slot_offset(int i) {
1926     return cell_offset(stack_slot_local_offset(i));
1927   }
1928 
1929   static ByteSize type_offset(int i) {
1930     return cell_offset(type_local_offset(i));
1931   }
1932 };
1933 
1934 // SpeculativeTrapData
1935 //
1936 // A SpeculativeTrapData is used to record traps due to type
1937 // speculation. It records the root of the compilation: that type
1938 // speculation is wrong in the context of one compilation (for
1939 // method1) doesn't mean it's wrong in the context of another one (for
1940 // method2). Type speculation could have more/different data in the
1941 // context of the compilation of method2 and it's worthwhile to try an
1942 // optimization that failed for compilation of method1 in the context
1943 // of compilation of method2.
1944 // Space for SpeculativeTrapData entries is allocated from the extra
1945 // data space in the MDO. If we run out of space, the trap data for
1946 // the ProfileData at that bci is updated.
1947 class SpeculativeTrapData : public ProfileData {
1948 protected:
1949   enum {
1950     speculative_trap_method,
1951     speculative_trap_cell_count
1952   };
1953 public:
1954   SpeculativeTrapData(DataLayout* layout) : ProfileData(layout) {
1955     assert(layout->tag() == DataLayout::speculative_trap_data_tag, "wrong type");
1956   }
1957 
1958   virtual bool is_SpeculativeTrapData() const { return true; }
1959 
1960   static int static_cell_count() {
1961     return speculative_trap_cell_count;
1962   }
1963 
1964   virtual int cell_count() const {
1965     return static_cell_count();
1966   }
1967 
1968   // Direct accessor
1969   Method* method() const {
1970     return (Method*)intptr_at(speculative_trap_method);
1971   }
1972 
1973   void set_method(Method* m) {
1974     set_intptr_at(speculative_trap_method, (intptr_t)m);
1975   }
1976 
1977   static ByteSize method_offset() {
1978     return cell_offset(speculative_trap_method);
1979   }
1980 
1981   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1982 };
1983 
1984 // MethodData*
1985 //
1986 // A MethodData* holds information which has been collected about
1987 // a method.  Its layout looks like this:
1988 //
1989 // -----------------------------
1990 // | header                    |
1991 // | klass                     |
1992 // -----------------------------
1993 // | method                    |
1994 // | size of the MethodData* |
1995 // -----------------------------
1996 // | Data entries...           |
1997 // |   (variable size)         |
1998 // |                           |
1999 // .                           .
2000 // .                           .
2001 // .                           .
2002 // |                           |
2003 // -----------------------------
2004 //
2005 // The data entry area is a heterogeneous array of DataLayouts. Each
2006 // DataLayout in the array corresponds to a specific bytecode in the
2007 // method.  The entries in the array are sorted by the corresponding
2008 // bytecode.  Access to the data is via resource-allocated ProfileData,
2009 // which point to the underlying blocks of DataLayout structures.
2010 //
2011 // During interpretation, if profiling in enabled, the interpreter
2012 // maintains a method data pointer (mdp), which points at the entry
2013 // in the array corresponding to the current bci.  In the course of
2014 // intepretation, when a bytecode is encountered that has profile data
2015 // associated with it, the entry pointed to by mdp is updated, then the
2016 // mdp is adjusted to point to the next appropriate DataLayout.  If mdp
2017 // is NULL to begin with, the interpreter assumes that the current method
2018 // is not (yet) being profiled.
2019 //
2020 // In MethodData* parlance, "dp" is a "data pointer", the actual address
2021 // of a DataLayout element.  A "di" is a "data index", the offset in bytes
2022 // from the base of the data entry array.  A "displacement" is the byte offset
2023 // in certain ProfileData objects that indicate the amount the mdp must be
2024 // adjusted in the event of a change in control flow.
2025 //
2026 
2027 CC_INTERP_ONLY(class BytecodeInterpreter;)
2028 class CleanExtraDataClosure;
2029 
2030 class MethodData : public Metadata {
2031   friend class VMStructs;
2032   CC_INTERP_ONLY(friend class BytecodeInterpreter;)
2033 private:
2034   friend class ProfileData;
2035 
2036   // Back pointer to the Method*
2037   Method* _method;
2038 
2039   // Size of this oop in bytes
2040   int _size;
2041 
2042   // Cached hint for bci_to_dp and bci_to_data
2043   int _hint_di;
2044 
2045   Mutex _extra_data_lock;
2046 
2047   MethodData(methodHandle method, int size, TRAPS);
2048 public:
2049   static MethodData* allocate(ClassLoaderData* loader_data, methodHandle method, TRAPS);
2050   MethodData() : _extra_data_lock(Monitor::leaf, "MDO extra data lock") {}; // For ciMethodData
2051 
2052   bool is_methodData() const volatile { return true; }
2053 
2054   // Whole-method sticky bits and flags
2055   enum {
2056     _trap_hist_limit    = 21,   // decoupled from Deoptimization::Reason_LIMIT
2057     _trap_hist_mask     = max_jubyte,
2058     _extra_data_count   = 4     // extra DataLayout headers, for trap history
2059   }; // Public flag values
2060 private:
2061   uint _nof_decompiles;             // count of all nmethod removals
2062   uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
2063   uint _nof_overflow_traps;         // trap count, excluding _trap_hist
2064   union {
2065     intptr_t _align;
2066     u1 _array[_trap_hist_limit];
2067   } _trap_hist;
2068 
2069   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2070   intx              _eflags;          // flags on escape information
2071   intx              _arg_local;       // bit set of non-escaping arguments
2072   intx              _arg_stack;       // bit set of stack-allocatable arguments
2073   intx              _arg_returned;    // bit set of returned arguments
2074 
2075   int _creation_mileage;              // method mileage at MDO creation
2076 
2077   // How many invocations has this MDO seen?
2078   // These counters are used to determine the exact age of MDO.
2079   // We need those because in tiered a method can be concurrently
2080   // executed at different levels.
2081   InvocationCounter _invocation_counter;
2082   // Same for backedges.
2083   InvocationCounter _backedge_counter;
2084   // Counter values at the time profiling started.
2085   int               _invocation_counter_start;
2086   int               _backedge_counter_start;
2087   uint              _tenure_traps;
2088 
2089 #if INCLUDE_RTM_OPT
2090   // State of RTM code generation during compilation of the method
2091   int               _rtm_state;
2092 #endif
2093 
2094   // Number of loops and blocks is computed when compiling the first
2095   // time with C1. It is used to determine if method is trivial.
2096   short             _num_loops;
2097   short             _num_blocks;
2098   // Highest compile level this method has ever seen.
2099   u1                _highest_comp_level;
2100   // Same for OSR level
2101   u1                _highest_osr_comp_level;
2102   // Does this method contain anything worth profiling?
2103   bool              _would_profile;
2104 
2105   // Size of _data array in bytes.  (Excludes header and extra_data fields.)
2106   int _data_size;
2107 
2108   // data index for the area dedicated to parameters. -1 if no
2109   // parameter profiling.
2110   int _parameters_type_data_di;
2111 
2112   // Beginning of the data entries
2113   intptr_t _data[1];
2114 
2115   // Helper for size computation
2116   static int compute_data_size(BytecodeStream* stream);
2117   static int bytecode_cell_count(Bytecodes::Code code);
2118   static bool is_speculative_trap_bytecode(Bytecodes::Code code);
2119   enum { no_profile_data = -1, variable_cell_count = -2 };
2120 
2121   // Helper for initialization
2122   DataLayout* data_layout_at(int data_index) const {
2123     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
2124     return (DataLayout*) (((address)_data) + data_index);
2125   }
2126 
2127   // Initialize an individual data segment.  Returns the size of
2128   // the segment in bytes.
2129   int initialize_data(BytecodeStream* stream, int data_index);
2130 
2131   // Helper for data_at
2132   DataLayout* limit_data_position() const {
2133     return (DataLayout*)((address)data_base() + _data_size);
2134   }
2135   bool out_of_bounds(int data_index) const {
2136     return data_index >= data_size();
2137   }
2138 
2139   // Give each of the data entries a chance to perform specific
2140   // data initialization.
2141   void post_initialize(BytecodeStream* stream);
2142 
2143   // hint accessors
2144   int      hint_di() const  { return _hint_di; }
2145   void set_hint_di(int di)  {
2146     assert(!out_of_bounds(di), "hint_di out of bounds");
2147     _hint_di = di;
2148   }
2149   ProfileData* data_before(int bci) {
2150     // avoid SEGV on this edge case
2151     if (data_size() == 0)
2152       return NULL;
2153     int hint = hint_di();
2154     if (data_layout_at(hint)->bci() <= bci)
2155       return data_at(hint);
2156     return first_data();
2157   }
2158 
2159   // What is the index of the first data entry?
2160   int first_di() const { return 0; }
2161 
2162   ProfileData* bci_to_extra_data_helper(int bci, Method* m, DataLayout*& dp, bool concurrent);
2163   // Find or create an extra ProfileData:
2164   ProfileData* bci_to_extra_data(int bci, Method* m, bool create_if_missing);
2165 
2166   // return the argument info cell
2167   ArgInfoData *arg_info();
2168 
2169   enum {
2170     no_type_profile = 0,
2171     type_profile_jsr292 = 1,
2172     type_profile_all = 2
2173   };
2174 
2175   static bool profile_jsr292(methodHandle m, int bci);
2176   static int profile_arguments_flag();
2177   static bool profile_all_arguments();
2178   static bool profile_arguments_for_invoke(methodHandle m, int bci);
2179   static int profile_return_flag();
2180   static bool profile_all_return();
2181   static bool profile_return_for_invoke(methodHandle m, int bci);
2182   static int profile_parameters_flag();
2183   static bool profile_parameters_jsr292_only();
2184   static bool profile_all_parameters();
2185 
2186   void clean_extra_data(CleanExtraDataClosure* cl);
2187   void clean_extra_data_helper(DataLayout* dp, int shift, bool reset = false);
2188   void verify_extra_data_clean(CleanExtraDataClosure* cl);
2189 
2190 public:
2191   static int header_size() {
2192     return sizeof(MethodData)/wordSize;
2193   }
2194 
2195   // Compute the size of a MethodData* before it is created.
2196   static int compute_allocation_size_in_bytes(methodHandle method);
2197   static int compute_allocation_size_in_words(methodHandle method);
2198   static int compute_extra_data_count(int data_size, int empty_bc_count, bool needs_speculative_traps);
2199 
2200   // Determine if a given bytecode can have profile information.
2201   static bool bytecode_has_profile(Bytecodes::Code code) {
2202     return bytecode_cell_count(code) != no_profile_data;
2203   }
2204 
2205   // reset into original state
2206   void init();
2207 
2208   // My size
2209   int size_in_bytes() const { return _size; }
2210   int size() const    { return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord); }
2211 #if INCLUDE_SERVICES
2212   void collect_statistics(KlassSizeStats *sz) const;
2213 #endif
2214 
2215   int      creation_mileage() const  { return _creation_mileage; }
2216   void set_creation_mileage(int x)   { _creation_mileage = x; }
2217 
2218   int invocation_count() {
2219     if (invocation_counter()->carry()) {
2220       return InvocationCounter::count_limit;
2221     }
2222     return invocation_counter()->count();
2223   }
2224   int backedge_count() {
2225     if (backedge_counter()->carry()) {
2226       return InvocationCounter::count_limit;
2227     }
2228     return backedge_counter()->count();
2229   }
2230 
2231   int invocation_count_start() {
2232     if (invocation_counter()->carry()) {
2233       return 0;
2234     }
2235     return _invocation_counter_start;
2236   }
2237 
2238   int backedge_count_start() {
2239     if (backedge_counter()->carry()) {
2240       return 0;
2241     }
2242     return _backedge_counter_start;
2243   }
2244 
2245   int invocation_count_delta() { return invocation_count() - invocation_count_start(); }
2246   int backedge_count_delta()   { return backedge_count()   - backedge_count_start();   }
2247 
2248   void reset_start_counters() {
2249     _invocation_counter_start = invocation_count();
2250     _backedge_counter_start = backedge_count();
2251   }
2252 
2253   InvocationCounter* invocation_counter()     { return &_invocation_counter; }
2254   InvocationCounter* backedge_counter()       { return &_backedge_counter;   }
2255 
2256 #if INCLUDE_RTM_OPT
2257   int rtm_state() const {
2258     return _rtm_state;
2259   }
2260   void set_rtm_state(RTMState rstate) {
2261     _rtm_state = (int)rstate;
2262   }
2263   void atomic_set_rtm_state(RTMState rstate) {
2264     Atomic::store((int)rstate, &_rtm_state);
2265   }
2266 
2267   static int rtm_state_offset_in_bytes() {
2268     return offset_of(MethodData, _rtm_state);
2269   }
2270 #endif
2271 
2272   void set_would_profile(bool p)              { _would_profile = p;    }
2273   bool would_profile() const                  { return _would_profile; }
2274 
2275   int highest_comp_level() const              { return _highest_comp_level;      }
2276   void set_highest_comp_level(int level)      { _highest_comp_level = level;     }
2277   int highest_osr_comp_level() const          { return _highest_osr_comp_level;  }
2278   void set_highest_osr_comp_level(int level)  { _highest_osr_comp_level = level; }
2279 
2280   int num_loops() const                       { return _num_loops;  }
2281   void set_num_loops(int n)                   { _num_loops = n;     }
2282   int num_blocks() const                      { return _num_blocks; }
2283   void set_num_blocks(int n)                  { _num_blocks = n;    }
2284 
2285   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
2286   static int mileage_of(Method* m);
2287 
2288   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2289   enum EscapeFlag {
2290     estimated    = 1 << 0,
2291     return_local = 1 << 1,
2292     return_allocated = 1 << 2,
2293     allocated_escapes = 1 << 3,
2294     unknown_modified = 1 << 4
2295   };
2296 
2297   intx eflags()                                  { return _eflags; }
2298   intx arg_local()                               { return _arg_local; }
2299   intx arg_stack()                               { return _arg_stack; }
2300   intx arg_returned()                            { return _arg_returned; }
2301   uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
2302                                                    assert(aid != NULL, "arg_info must be not null");
2303                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
2304                                                    return aid->arg_modified(a); }
2305 
2306   void set_eflags(intx v)                        { _eflags = v; }
2307   void set_arg_local(intx v)                     { _arg_local = v; }
2308   void set_arg_stack(intx v)                     { _arg_stack = v; }
2309   void set_arg_returned(intx v)                  { _arg_returned = v; }
2310   void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
2311                                                    assert(aid != NULL, "arg_info must be not null");
2312                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
2313                                                    aid->set_arg_modified(a, v); }
2314 
2315   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
2316 
2317   // Location and size of data area
2318   address data_base() const {
2319     return (address) _data;
2320   }
2321   int data_size() const {
2322     return _data_size;
2323   }
2324 
2325   // Accessors
2326   Method* method() const { return _method; }
2327 
2328   // Get the data at an arbitrary (sort of) data index.
2329   ProfileData* data_at(int data_index) const;
2330 
2331   // Walk through the data in order.
2332   ProfileData* first_data() const { return data_at(first_di()); }
2333   ProfileData* next_data(ProfileData* current) const;
2334   bool is_valid(ProfileData* current) const { return current != NULL; }
2335 
2336   // Convert a dp (data pointer) to a di (data index).
2337   int dp_to_di(address dp) const {
2338     return dp - ((address)_data);
2339   }
2340 
2341   // bci to di/dp conversion.
2342   address bci_to_dp(int bci);
2343   int bci_to_di(int bci) {
2344     return dp_to_di(bci_to_dp(bci));
2345   }
2346 
2347   // Get the data at an arbitrary bci, or NULL if there is none.
2348   ProfileData* bci_to_data(int bci);
2349 
2350   // Same, but try to create an extra_data record if one is needed:
2351   ProfileData* allocate_bci_to_data(int bci, Method* m) {
2352     ProfileData* data = NULL;
2353     // If m not NULL, try to allocate a SpeculativeTrapData entry
2354     if (m == NULL) {
2355       data = bci_to_data(bci);
2356     }
2357     if (data != NULL) {
2358       return data;
2359     }
2360     data = bci_to_extra_data(bci, m, true);
2361     if (data != NULL) {
2362       return data;
2363     }
2364     // If SpeculativeTrapData allocation fails try to allocate a
2365     // regular entry
2366     data = bci_to_data(bci);
2367     if (data != NULL) {
2368       return data;
2369     }
2370     return bci_to_extra_data(bci, NULL, true);
2371   }
2372 
2373   // Add a handful of extra data records, for trap tracking.
2374   DataLayout* extra_data_base() const { return limit_data_position(); }
2375   DataLayout* extra_data_limit() const { return (DataLayout*)((address)this + size_in_bytes()); }
2376   int extra_data_size() const { return (address)extra_data_limit()
2377                                - (address)extra_data_base(); }
2378   static DataLayout* next_extra(DataLayout* dp);
2379 
2380   // Return (uint)-1 for overflow.
2381   uint trap_count(int reason) const {
2382     assert((uint)reason < _trap_hist_limit, "oob");
2383     return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
2384   }
2385   // For loops:
2386   static uint trap_reason_limit() { return _trap_hist_limit; }
2387   static uint trap_count_limit()  { return _trap_hist_mask; }
2388   uint inc_trap_count(int reason) {
2389     // Count another trap, anywhere in this method.
2390     assert(reason >= 0, "must be single trap");
2391     if ((uint)reason < _trap_hist_limit) {
2392       uint cnt1 = 1 + _trap_hist._array[reason];
2393       if ((cnt1 & _trap_hist_mask) != 0) {  // if no counter overflow...
2394         _trap_hist._array[reason] = cnt1;
2395         return cnt1;
2396       } else {
2397         return _trap_hist_mask + (++_nof_overflow_traps);
2398       }
2399     } else {
2400       // Could not represent the count in the histogram.
2401       return (++_nof_overflow_traps);
2402     }
2403   }
2404 
2405   uint overflow_trap_count() const {
2406     return _nof_overflow_traps;
2407   }
2408   uint overflow_recompile_count() const {
2409     return _nof_overflow_recompiles;
2410   }
2411   void inc_overflow_recompile_count() {
2412     _nof_overflow_recompiles += 1;
2413   }
2414   uint decompile_count() const {
2415     return _nof_decompiles;
2416   }
2417   void inc_decompile_count() {
2418     _nof_decompiles += 1;
2419     if (decompile_count() > (uint)PerMethodRecompilationCutoff) {
2420       method()->set_not_compilable(CompLevel_full_optimization, true, "decompile_count > PerMethodRecompilationCutoff");
2421     }
2422   }
2423   uint tenure_traps() const {
2424     return _tenure_traps;
2425   }
2426   void inc_tenure_traps() {
2427     _tenure_traps += 1;
2428   }
2429 
2430   // Return pointer to area dedicated to parameters in MDO
2431   ParametersTypeData* parameters_type_data() const {
2432     return _parameters_type_data_di != -1 ? data_layout_at(_parameters_type_data_di)->data_in()->as_ParametersTypeData() : NULL;
2433   }
2434 
2435   int parameters_type_data_di() const {
2436     assert(_parameters_type_data_di != -1, "no args type data");
2437     return _parameters_type_data_di;
2438   }
2439 
2440   // Support for code generation
2441   static ByteSize data_offset() {
2442     return byte_offset_of(MethodData, _data[0]);
2443   }
2444 
2445   static ByteSize invocation_counter_offset() {
2446     return byte_offset_of(MethodData, _invocation_counter);
2447   }
2448   static ByteSize backedge_counter_offset() {
2449     return byte_offset_of(MethodData, _backedge_counter);
2450   }
2451 
2452   static ByteSize parameters_type_data_di_offset() {
2453     return byte_offset_of(MethodData, _parameters_type_data_di);
2454   }
2455 
2456   // Deallocation support - no pointer fields to deallocate
2457   void deallocate_contents(ClassLoaderData* loader_data) {}
2458 
2459   // GC support
2460   void set_size(int object_size_in_bytes) { _size = object_size_in_bytes; }
2461 
2462   // Printing
2463   void print_on      (outputStream* st) const;
2464   void print_value_on(outputStream* st) const;
2465 
2466   // printing support for method data
2467   void print_data_on(outputStream* st) const;
2468 
2469   const char* internal_name() const { return "{method data}"; }
2470 
2471   // verification
2472   void verify_on(outputStream* st);
2473   void verify_data_on(outputStream* st);
2474 
2475   static bool profile_parameters_for_method(methodHandle m);
2476   static bool profile_arguments();
2477   static bool profile_arguments_jsr292_only();
2478   static bool profile_return();
2479   static bool profile_parameters();
2480   static bool profile_return_jsr292_only();
2481 
2482   void clean_method_data(BoolObjectClosure* is_alive);
2483 
2484   void clean_weak_method_links();
2485 };
2486 
2487 #endif // SHARE_VM_OOPS_METHODDATAOOP_HPP