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).
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  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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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   DEBUG_ONLY(void verify_clean_weak_method_links();)
 258 };
 259 
 260 
 261 // ProfileData class hierarchy
 262 class ProfileData;
 263 class   BitData;
 264 class     CounterData;
 265 class       ReceiverTypeData;
 266 class         VirtualCallData;
 267 class           VirtualCallTypeData;
 268 class       RetData;
 269 class       CallTypeData;
 270 class   JumpData;
 271 class     BranchData;
 272 class   ArrayData;
 273 class     MultiBranchData;
 274 class     ArgInfoData;
 275 class     ParametersTypeData;
 276 class   SpeculativeTrapData;
 277 
 278 // ProfileData
 279 //
 280 // A ProfileData object is created to refer to a section of profiling
 281 // data in a structured way.
 282 class ProfileData : public ResourceObj {
 283   friend class TypeEntries;
 284   friend class ReturnTypeEntry;
 285   friend class TypeStackSlotEntries;
 286 private:
 287   enum {
 288     tab_width_one = 16,
 289     tab_width_two = 36
 290   };
 291 
 292   // This is a pointer to a section of profiling data.
 293   DataLayout* _data;
 294 
 295   char* print_data_on_helper(const MethodData* md) const;
 296 
 297 protected:
 298   DataLayout* data() { return _data; }
 299   const DataLayout* data() const { return _data; }
 300 
 301   enum {
 302     cell_size = DataLayout::cell_size
 303   };
 304 
 305 public:
 306   // How many cells are in this?
 307   virtual int cell_count() const {
 308     ShouldNotReachHere();
 309     return -1;
 310   }
 311 
 312   // Return the size of this data.
 313   int size_in_bytes() {
 314     return DataLayout::compute_size_in_bytes(cell_count());
 315   }
 316 
 317 protected:
 318   // Low-level accessors for underlying data
 319   void set_intptr_at(int index, intptr_t value) {
 320     assert(0 <= index && index < cell_count(), "oob");
 321     data()->set_cell_at(index, value);
 322   }
 323   void release_set_intptr_at(int index, intptr_t value) {
 324     assert(0 <= index && index < cell_count(), "oob");
 325     data()->release_set_cell_at(index, value);
 326   }
 327   intptr_t intptr_at(int index) const {
 328     assert(0 <= index && index < cell_count(), "oob");
 329     return data()->cell_at(index);
 330   }
 331   void set_uint_at(int index, uint value) {
 332     set_intptr_at(index, (intptr_t) value);
 333   }
 334   void release_set_uint_at(int index, uint value) {
 335     release_set_intptr_at(index, (intptr_t) value);
 336   }
 337   uint uint_at(int index) const {
 338     return (uint)intptr_at(index);
 339   }
 340   void set_int_at(int index, int value) {
 341     set_intptr_at(index, (intptr_t) value);
 342   }
 343   void release_set_int_at(int index, int value) {
 344     release_set_intptr_at(index, (intptr_t) value);
 345   }
 346   int int_at(int index) const {
 347     return (int)intptr_at(index);
 348   }
 349   int int_at_unchecked(int index) const {
 350     return (int)data()->cell_at(index);
 351   }
 352   void set_oop_at(int index, oop value) {
 353     set_intptr_at(index, cast_from_oop<intptr_t>(value));
 354   }
 355   oop oop_at(int index) const {
 356     return cast_to_oop(intptr_at(index));
 357   }
 358 
 359   void set_flag_at(int flag_number) {
 360     data()->set_flag_at(flag_number);
 361   }
 362   bool flag_at(int flag_number) const {
 363     return data()->flag_at(flag_number);
 364   }
 365 
 366   // two convenient imports for use by subclasses:
 367   static ByteSize cell_offset(int index) {
 368     return DataLayout::cell_offset(index);
 369   }
 370   static int flag_number_to_byte_constant(int flag_number) {
 371     return DataLayout::flag_number_to_byte_constant(flag_number);
 372   }
 373 
 374   ProfileData(DataLayout* data) {
 375     _data = data;
 376   }
 377 
 378 #ifdef CC_INTERP
 379   // Static low level accessors for DataLayout with ProfileData's semantics.
 380 
 381   static int cell_offset_in_bytes(int index) {
 382     return DataLayout::cell_offset_in_bytes(index);
 383   }
 384 
 385   static void increment_uint_at_no_overflow(DataLayout* layout, int index,
 386                                             int inc = DataLayout::counter_increment) {
 387     uint count = ((uint)layout->cell_at(index)) + inc;
 388     if (count == 0) return;
 389     layout->set_cell_at(index, (intptr_t) count);
 390   }
 391 
 392   static int int_at(DataLayout* layout, int index) {
 393     return (int)layout->cell_at(index);
 394   }
 395 
 396   static int uint_at(DataLayout* layout, int index) {
 397     return (uint)layout->cell_at(index);
 398   }
 399 
 400   static oop oop_at(DataLayout* layout, int index) {
 401     return cast_to_oop(layout->cell_at(index));
 402   }
 403 
 404   static void set_intptr_at(DataLayout* layout, int index, intptr_t value) {
 405     layout->set_cell_at(index, (intptr_t) value);
 406   }
 407 
 408   static void set_flag_at(DataLayout* layout, int flag_number) {
 409     layout->set_flag_at(flag_number);
 410   }
 411 #endif // CC_INTERP
 412 
 413 public:
 414   // Constructor for invalid ProfileData.
 415   ProfileData();
 416 
 417   u2 bci() const {
 418     return data()->bci();
 419   }
 420 
 421   address dp() {
 422     return (address)_data;
 423   }
 424 
 425   int trap_state() const {
 426     return data()->trap_state();
 427   }
 428   void set_trap_state(int new_state) {
 429     data()->set_trap_state(new_state);
 430   }
 431 
 432   // Type checking
 433   virtual bool is_BitData()         const { return false; }
 434   virtual bool is_CounterData()     const { return false; }
 435   virtual bool is_JumpData()        const { return false; }
 436   virtual bool is_ReceiverTypeData()const { return false; }
 437   virtual bool is_VirtualCallData() const { return false; }
 438   virtual bool is_RetData()         const { return false; }
 439   virtual bool is_BranchData()      const { return false; }
 440   virtual bool is_ArrayData()       const { return false; }
 441   virtual bool is_MultiBranchData() const { return false; }
 442   virtual bool is_ArgInfoData()     const { return false; }
 443   virtual bool is_CallTypeData()    const { return false; }
 444   virtual bool is_VirtualCallTypeData()const { return false; }
 445   virtual bool is_ParametersTypeData() const { return false; }
 446   virtual bool is_SpeculativeTrapData()const { return false; }
 447 
 448 
 449   BitData* as_BitData() const {
 450     assert(is_BitData(), "wrong type");
 451     return is_BitData()         ? (BitData*)        this : NULL;
 452   }
 453   CounterData* as_CounterData() const {
 454     assert(is_CounterData(), "wrong type");
 455     return is_CounterData()     ? (CounterData*)    this : NULL;
 456   }
 457   JumpData* as_JumpData() const {
 458     assert(is_JumpData(), "wrong type");
 459     return is_JumpData()        ? (JumpData*)       this : NULL;
 460   }
 461   ReceiverTypeData* as_ReceiverTypeData() const {
 462     assert(is_ReceiverTypeData(), "wrong type");
 463     return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
 464   }
 465   VirtualCallData* as_VirtualCallData() const {
 466     assert(is_VirtualCallData(), "wrong type");
 467     return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
 468   }
 469   RetData* as_RetData() const {
 470     assert(is_RetData(), "wrong type");
 471     return is_RetData()         ? (RetData*)        this : NULL;
 472   }
 473   BranchData* as_BranchData() const {
 474     assert(is_BranchData(), "wrong type");
 475     return is_BranchData()      ? (BranchData*)     this : NULL;
 476   }
 477   ArrayData* as_ArrayData() const {
 478     assert(is_ArrayData(), "wrong type");
 479     return is_ArrayData()       ? (ArrayData*)      this : NULL;
 480   }
 481   MultiBranchData* as_MultiBranchData() const {
 482     assert(is_MultiBranchData(), "wrong type");
 483     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
 484   }
 485   ArgInfoData* as_ArgInfoData() const {
 486     assert(is_ArgInfoData(), "wrong type");
 487     return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
 488   }
 489   CallTypeData* as_CallTypeData() const {
 490     assert(is_CallTypeData(), "wrong type");
 491     return is_CallTypeData() ? (CallTypeData*)this : NULL;
 492   }
 493   VirtualCallTypeData* as_VirtualCallTypeData() const {
 494     assert(is_VirtualCallTypeData(), "wrong type");
 495     return is_VirtualCallTypeData() ? (VirtualCallTypeData*)this : NULL;
 496   }
 497   ParametersTypeData* as_ParametersTypeData() const {
 498     assert(is_ParametersTypeData(), "wrong type");
 499     return is_ParametersTypeData() ? (ParametersTypeData*)this : NULL;
 500   }
 501   SpeculativeTrapData* as_SpeculativeTrapData() const {
 502     assert(is_SpeculativeTrapData(), "wrong type");
 503     return is_SpeculativeTrapData() ? (SpeculativeTrapData*)this : NULL;
 504   }
 505 
 506 
 507   // Subclass specific initialization
 508   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo) {}
 509 
 510   // GC support
 511   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {}
 512 
 513   // Redefinition support
 514   virtual void clean_weak_method_links() {}
 515   DEBUG_ONLY(virtual void verify_clean_weak_method_links() {})
 516 
 517   // CI translation: ProfileData can represent both MethodDataOop data
 518   // as well as CIMethodData data. This function is provided for translating
 519   // an oop in a ProfileData to the ci equivalent. Generally speaking,
 520   // most ProfileData don't require any translation, so we provide the null
 521   // translation here, and the required translators are in the ci subclasses.
 522   virtual void translate_from(const ProfileData* data) {}
 523 
 524   virtual void print_data_on(outputStream* st, const char* extra = NULL) const {
 525     ShouldNotReachHere();
 526   }
 527 
 528   void print_data_on(outputStream* st, const MethodData* md) const;
 529 
 530   void print_shared(outputStream* st, const char* name, const char* extra) const;
 531   void tab(outputStream* st, bool first = false) const;
 532 };
 533 
 534 // BitData
 535 //
 536 // A BitData holds a flag or two in its header.
 537 class BitData : public ProfileData {
 538 protected:
 539   enum {
 540     // null_seen:
 541     //  saw a null operand (cast/aastore/instanceof)
 542     null_seen_flag              = DataLayout::first_flag + 0
 543   };
 544   enum { bit_cell_count = 0 };  // no additional data fields needed.
 545 public:
 546   BitData(DataLayout* layout) : ProfileData(layout) {
 547   }
 548 
 549   virtual bool is_BitData() const { return true; }
 550 
 551   static int static_cell_count() {
 552     return bit_cell_count;
 553   }
 554 
 555   virtual int cell_count() const {
 556     return static_cell_count();
 557   }
 558 
 559   // Accessor
 560 
 561   // The null_seen flag bit is specially known to the interpreter.
 562   // Consulting it allows the compiler to avoid setting up null_check traps.
 563   bool null_seen()     { return flag_at(null_seen_flag); }
 564   void set_null_seen()    { set_flag_at(null_seen_flag); }
 565 
 566 
 567   // Code generation support
 568   static int null_seen_byte_constant() {
 569     return flag_number_to_byte_constant(null_seen_flag);
 570   }
 571 
 572   static ByteSize bit_data_size() {
 573     return cell_offset(bit_cell_count);
 574   }
 575 
 576 #ifdef CC_INTERP
 577   static int bit_data_size_in_bytes() {
 578     return cell_offset_in_bytes(bit_cell_count);
 579   }
 580 
 581   static void set_null_seen(DataLayout* layout) {
 582     set_flag_at(layout, null_seen_flag);
 583   }
 584 
 585   static DataLayout* advance(DataLayout* layout) {
 586     return (DataLayout*) (((address)layout) + (ssize_t)BitData::bit_data_size_in_bytes());
 587   }
 588 #endif // CC_INTERP
 589 
 590   void print_data_on(outputStream* st, const char* extra = NULL) const;
 591 };
 592 
 593 // CounterData
 594 //
 595 // A CounterData corresponds to a simple counter.
 596 class CounterData : public BitData {
 597 protected:
 598   enum {
 599     count_off,
 600     counter_cell_count
 601   };
 602 public:
 603   CounterData(DataLayout* layout) : BitData(layout) {}
 604 
 605   virtual bool is_CounterData() const { return true; }
 606 
 607   static int static_cell_count() {
 608     return counter_cell_count;
 609   }
 610 
 611   virtual int cell_count() const {
 612     return static_cell_count();
 613   }
 614 
 615   // Direct accessor
 616   uint count() const {
 617     return uint_at(count_off);
 618   }
 619 
 620   // Code generation support
 621   static ByteSize count_offset() {
 622     return cell_offset(count_off);
 623   }
 624   static ByteSize counter_data_size() {
 625     return cell_offset(counter_cell_count);
 626   }
 627 
 628   void set_count(uint count) {
 629     set_uint_at(count_off, count);
 630   }
 631 
 632 #ifdef CC_INTERP
 633   static int counter_data_size_in_bytes() {
 634     return cell_offset_in_bytes(counter_cell_count);
 635   }
 636 
 637   static void increment_count_no_overflow(DataLayout* layout) {
 638     increment_uint_at_no_overflow(layout, count_off);
 639   }
 640 
 641   // Support counter decrementation at checkcast / subtype check failed.
 642   static void decrement_count(DataLayout* layout) {
 643     increment_uint_at_no_overflow(layout, count_off, -1);
 644   }
 645 
 646   static DataLayout* advance(DataLayout* layout) {
 647     return (DataLayout*) (((address)layout) + (ssize_t)CounterData::counter_data_size_in_bytes());
 648   }
 649 #endif // CC_INTERP
 650 
 651   void print_data_on(outputStream* st, const char* extra = NULL) const;
 652 };
 653 
 654 // JumpData
 655 //
 656 // A JumpData is used to access profiling information for a direct
 657 // branch.  It is a counter, used for counting the number of branches,
 658 // plus a data displacement, used for realigning the data pointer to
 659 // the corresponding target bci.
 660 class JumpData : public ProfileData {
 661 protected:
 662   enum {
 663     taken_off_set,
 664     displacement_off_set,
 665     jump_cell_count
 666   };
 667 
 668   void set_displacement(int displacement) {
 669     set_int_at(displacement_off_set, displacement);
 670   }
 671 
 672 public:
 673   JumpData(DataLayout* layout) : ProfileData(layout) {
 674     assert(layout->tag() == DataLayout::jump_data_tag ||
 675       layout->tag() == DataLayout::branch_data_tag, "wrong type");
 676   }
 677 
 678   virtual bool is_JumpData() const { return true; }
 679 
 680   static int static_cell_count() {
 681     return jump_cell_count;
 682   }
 683 
 684   virtual int cell_count() const {
 685     return static_cell_count();
 686   }
 687 
 688   // Direct accessor
 689   uint taken() const {
 690     return uint_at(taken_off_set);
 691   }
 692 
 693   void set_taken(uint cnt) {
 694     set_uint_at(taken_off_set, cnt);
 695   }
 696 
 697   // Saturating counter
 698   uint inc_taken() {
 699     uint cnt = taken() + 1;
 700     // Did we wrap? Will compiler screw us??
 701     if (cnt == 0) cnt--;
 702     set_uint_at(taken_off_set, cnt);
 703     return cnt;
 704   }
 705 
 706   int displacement() const {
 707     return int_at(displacement_off_set);
 708   }
 709 
 710   // Code generation support
 711   static ByteSize taken_offset() {
 712     return cell_offset(taken_off_set);
 713   }
 714 
 715   static ByteSize displacement_offset() {
 716     return cell_offset(displacement_off_set);
 717   }
 718 
 719 #ifdef CC_INTERP
 720   static void increment_taken_count_no_overflow(DataLayout* layout) {
 721     increment_uint_at_no_overflow(layout, taken_off_set);
 722   }
 723 
 724   static DataLayout* advance_taken(DataLayout* layout) {
 725     return (DataLayout*) (((address)layout) + (ssize_t)int_at(layout, displacement_off_set));
 726   }
 727 
 728   static uint taken_count(DataLayout* layout) {
 729     return (uint) uint_at(layout, taken_off_set);
 730   }
 731 #endif // CC_INTERP
 732 
 733   // Specific initialization.
 734   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 735 
 736   void print_data_on(outputStream* st, const char* extra = NULL) const;
 737 };
 738 
 739 // Entries in a ProfileData object to record types: it can either be
 740 // none (no profile), unknown (conflicting profile data) or a klass if
 741 // a single one is seen. Whether a null reference was seen is also
 742 // recorded. No counter is associated with the type and a single type
 743 // is tracked (unlike VirtualCallData).
 744 class TypeEntries {
 745 
 746 public:
 747 
 748   // A single cell is used to record information for a type:
 749   // - the cell is initialized to 0
 750   // - when a type is discovered it is stored in the cell
 751   // - bit zero of the cell is used to record whether a null reference
 752   // was encountered or not
 753   // - bit 1 is set to record a conflict in the type information
 754 
 755   enum {
 756     null_seen = 1,
 757     type_mask = ~null_seen,
 758     type_unknown = 2,
 759     status_bits = null_seen | type_unknown,
 760     type_klass_mask = ~status_bits
 761   };
 762 
 763   // what to initialize a cell to
 764   static intptr_t type_none() {
 765     return 0;
 766   }
 767 
 768   // null seen = bit 0 set?
 769   static bool was_null_seen(intptr_t v) {
 770     return (v & null_seen) != 0;
 771   }
 772 
 773   // conflicting type information = bit 1 set?
 774   static bool is_type_unknown(intptr_t v) {
 775     return (v & type_unknown) != 0;
 776   }
 777 
 778   // not type information yet = all bits cleared, ignoring bit 0?
 779   static bool is_type_none(intptr_t v) {
 780     return (v & type_mask) == 0;
 781   }
 782 
 783   // recorded type: cell without bit 0 and 1
 784   static intptr_t klass_part(intptr_t v) {
 785     intptr_t r = v & type_klass_mask;
 786     return r;
 787   }
 788 
 789   // type recorded
 790   static Klass* valid_klass(intptr_t k) {
 791     if (!is_type_none(k) &&
 792         !is_type_unknown(k)) {
 793       Klass* res = (Klass*)klass_part(k);
 794       assert(res != NULL, "invalid");
 795       return res;
 796     } else {
 797       return NULL;
 798     }
 799   }
 800 
 801   static intptr_t with_status(intptr_t k, intptr_t in) {
 802     return k | (in & status_bits);
 803   }
 804 
 805   static intptr_t with_status(Klass* k, intptr_t in) {
 806     return with_status((intptr_t)k, in);
 807   }
 808 
 809   static void print_klass(outputStream* st, intptr_t k);
 810 
 811   // GC support
 812   static bool is_loader_alive(BoolObjectClosure* is_alive_cl, intptr_t p);
 813 
 814 protected:
 815   // ProfileData object these entries are part of
 816   ProfileData* _pd;
 817   // offset within the ProfileData object where the entries start
 818   const int _base_off;
 819 
 820   TypeEntries(int base_off)
 821     : _base_off(base_off), _pd(NULL) {}
 822 
 823   void set_intptr_at(int index, intptr_t value) {
 824     _pd->set_intptr_at(index, value);
 825   }
 826 
 827   intptr_t intptr_at(int index) const {
 828     return _pd->intptr_at(index);
 829   }
 830 
 831 public:
 832   void set_profile_data(ProfileData* pd) {
 833     _pd = pd;
 834   }
 835 };
 836 
 837 // Type entries used for arguments passed at a call and parameters on
 838 // method entry. 2 cells per entry: one for the type encoded as in
 839 // TypeEntries and one initialized with the stack slot where the
 840 // profiled object is to be found so that the interpreter can locate
 841 // it quickly.
 842 class TypeStackSlotEntries : public TypeEntries {
 843 
 844 private:
 845   enum {
 846     stack_slot_entry,
 847     type_entry,
 848     per_arg_cell_count
 849   };
 850 
 851   // offset of cell for stack slot for entry i within ProfileData object
 852   int stack_slot_offset(int i) const {
 853     return _base_off + stack_slot_local_offset(i);
 854   }
 855 
 856   const int _number_of_entries;
 857 
 858   // offset of cell for type for entry i within ProfileData object
 859   int type_offset_in_cells(int i) const {
 860     return _base_off + type_local_offset(i);
 861   }
 862 
 863 public:
 864 
 865   TypeStackSlotEntries(int base_off, int nb_entries)
 866     : TypeEntries(base_off), _number_of_entries(nb_entries) {}
 867 
 868   static int compute_cell_count(Symbol* signature, bool include_receiver, int max);
 869 
 870   void post_initialize(Symbol* signature, bool has_receiver, bool include_receiver);
 871 
 872   int number_of_entries() const { return _number_of_entries; }
 873 
 874   // offset of cell for stack slot for entry i within this block of cells for a TypeStackSlotEntries
 875   static int stack_slot_local_offset(int i) {
 876     return i * per_arg_cell_count + stack_slot_entry;
 877   }
 878 
 879   // offset of cell for type for entry i within this block of cells for a TypeStackSlotEntries
 880   static int type_local_offset(int i) {
 881     return i * per_arg_cell_count + type_entry;
 882   }
 883 
 884   // stack slot for entry i
 885   uint stack_slot(int i) const {
 886     assert(i >= 0 && i < _number_of_entries, "oob");
 887     return _pd->uint_at(stack_slot_offset(i));
 888   }
 889 
 890   // set stack slot for entry i
 891   void set_stack_slot(int i, uint num) {
 892     assert(i >= 0 && i < _number_of_entries, "oob");
 893     _pd->set_uint_at(stack_slot_offset(i), num);
 894   }
 895 
 896   // type for entry i
 897   intptr_t type(int i) const {
 898     assert(i >= 0 && i < _number_of_entries, "oob");
 899     return _pd->intptr_at(type_offset_in_cells(i));
 900   }
 901 
 902   // set type for entry i
 903   void set_type(int i, intptr_t k) {
 904     assert(i >= 0 && i < _number_of_entries, "oob");
 905     _pd->set_intptr_at(type_offset_in_cells(i), k);
 906   }
 907 
 908   static ByteSize per_arg_size() {
 909     return in_ByteSize(per_arg_cell_count * DataLayout::cell_size);
 910   }
 911 
 912   static int per_arg_count() {
 913     return per_arg_cell_count;
 914   }
 915 
 916   ByteSize type_offset(int i) const {
 917     return DataLayout::cell_offset(type_offset_in_cells(i));
 918   }
 919 
 920   // GC support
 921   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 922 
 923   void print_data_on(outputStream* st) const;
 924 };
 925 
 926 // Type entry used for return from a call. A single cell to record the
 927 // type.
 928 class ReturnTypeEntry : public TypeEntries {
 929 
 930 private:
 931   enum {
 932     cell_count = 1
 933   };
 934 
 935 public:
 936   ReturnTypeEntry(int base_off)
 937     : TypeEntries(base_off) {}
 938 
 939   void post_initialize() {
 940     set_type(type_none());
 941   }
 942 
 943   intptr_t type() const {
 944     return _pd->intptr_at(_base_off);
 945   }
 946 
 947   void set_type(intptr_t k) {
 948     _pd->set_intptr_at(_base_off, k);
 949   }
 950 
 951   static int static_cell_count() {
 952     return cell_count;
 953   }
 954 
 955   static ByteSize size() {
 956     return in_ByteSize(cell_count * DataLayout::cell_size);
 957   }
 958 
 959   ByteSize type_offset() {
 960     return DataLayout::cell_offset(_base_off);
 961   }
 962 
 963   // GC support
 964   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 965 
 966   void print_data_on(outputStream* st) const;
 967 };
 968 
 969 // Entries to collect type information at a call: contains arguments
 970 // (TypeStackSlotEntries), a return type (ReturnTypeEntry) and a
 971 // number of cells. Because the number of cells for the return type is
 972 // smaller than the number of cells for the type of an arguments, the
 973 // number of cells is used to tell how many arguments are profiled and
 974 // whether a return value is profiled. See has_arguments() and
 975 // has_return().
 976 class TypeEntriesAtCall {
 977 private:
 978   static int stack_slot_local_offset(int i) {
 979     return header_cell_count() + TypeStackSlotEntries::stack_slot_local_offset(i);
 980   }
 981 
 982   static int argument_type_local_offset(int i) {
 983     return header_cell_count() + TypeStackSlotEntries::type_local_offset(i);
 984   }
 985 
 986 public:
 987 
 988   static int header_cell_count() {
 989     return 1;
 990   }
 991 
 992   static int cell_count_local_offset() {
 993     return 0;
 994   }
 995 
 996   static int compute_cell_count(BytecodeStream* stream);
 997 
 998   static void initialize(DataLayout* dl, int base, int cell_count) {
 999     int off = base + cell_count_local_offset();
1000     dl->set_cell_at(off, cell_count - base - header_cell_count());
1001   }
1002 
1003   static bool arguments_profiling_enabled();
1004   static bool return_profiling_enabled();
1005 
1006   // Code generation support
1007   static ByteSize cell_count_offset() {
1008     return in_ByteSize(cell_count_local_offset() * DataLayout::cell_size);
1009   }
1010 
1011   static ByteSize args_data_offset() {
1012     return in_ByteSize(header_cell_count() * DataLayout::cell_size);
1013   }
1014 
1015   static ByteSize stack_slot_offset(int i) {
1016     return in_ByteSize(stack_slot_local_offset(i) * DataLayout::cell_size);
1017   }
1018 
1019   static ByteSize argument_type_offset(int i) {
1020     return in_ByteSize(argument_type_local_offset(i) * DataLayout::cell_size);
1021   }
1022 
1023   static ByteSize return_only_size() {
1024     return ReturnTypeEntry::size() + in_ByteSize(header_cell_count() * DataLayout::cell_size);
1025   }
1026 
1027 };
1028 
1029 // CallTypeData
1030 //
1031 // A CallTypeData is used to access profiling information about a non
1032 // virtual call for which we collect type information about arguments
1033 // and return value.
1034 class CallTypeData : public CounterData {
1035 private:
1036   // entries for arguments if any
1037   TypeStackSlotEntries _args;
1038   // entry for return type if any
1039   ReturnTypeEntry _ret;
1040 
1041   int cell_count_global_offset() const {
1042     return CounterData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
1043   }
1044 
1045   // number of cells not counting the header
1046   int cell_count_no_header() const {
1047     return uint_at(cell_count_global_offset());
1048   }
1049 
1050   void check_number_of_arguments(int total) {
1051     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
1052   }
1053 
1054 public:
1055   CallTypeData(DataLayout* layout) :
1056     CounterData(layout),
1057     _args(CounterData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
1058     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
1059   {
1060     assert(layout->tag() == DataLayout::call_type_data_tag, "wrong type");
1061     // Some compilers (VC++) don't want this passed in member initialization list
1062     _args.set_profile_data(this);
1063     _ret.set_profile_data(this);
1064   }
1065 
1066   const TypeStackSlotEntries* args() const {
1067     assert(has_arguments(), "no profiling of arguments");
1068     return &_args;
1069   }
1070 
1071   const ReturnTypeEntry* ret() const {
1072     assert(has_return(), "no profiling of return value");
1073     return &_ret;
1074   }
1075 
1076   virtual bool is_CallTypeData() const { return true; }
1077 
1078   static int static_cell_count() {
1079     return -1;
1080   }
1081 
1082   static int compute_cell_count(BytecodeStream* stream) {
1083     return CounterData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
1084   }
1085 
1086   static void initialize(DataLayout* dl, int cell_count) {
1087     TypeEntriesAtCall::initialize(dl, CounterData::static_cell_count(), cell_count);
1088   }
1089 
1090   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1091 
1092   virtual int cell_count() const {
1093     return CounterData::static_cell_count() +
1094       TypeEntriesAtCall::header_cell_count() +
1095       int_at_unchecked(cell_count_global_offset());
1096   }
1097 
1098   int number_of_arguments() const {
1099     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
1100   }
1101 
1102   void set_argument_type(int i, Klass* k) {
1103     assert(has_arguments(), "no arguments!");
1104     intptr_t current = _args.type(i);
1105     _args.set_type(i, TypeEntries::with_status(k, current));
1106   }
1107 
1108   void set_return_type(Klass* k) {
1109     assert(has_return(), "no return!");
1110     intptr_t current = _ret.type();
1111     _ret.set_type(TypeEntries::with_status(k, current));
1112   }
1113 
1114   // An entry for a return value takes less space than an entry for an
1115   // argument so if the number of cells exceeds the number of cells
1116   // needed for an argument, this object contains type information for
1117   // at least one argument.
1118   bool has_arguments() const {
1119     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
1120     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
1121     return res;
1122   }
1123 
1124   // An entry for a return value takes less space than an entry for an
1125   // argument, so if the remainder of the number of cells divided by
1126   // the number of cells for an argument is not null, a return value
1127   // is profiled in this object.
1128   bool has_return() const {
1129     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
1130     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
1131     return res;
1132   }
1133 
1134   // Code generation support
1135   static ByteSize args_data_offset() {
1136     return cell_offset(CounterData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
1137   }
1138 
1139   ByteSize argument_type_offset(int i) {
1140     return _args.type_offset(i);
1141   }
1142 
1143   ByteSize return_type_offset() {
1144     return _ret.type_offset();
1145   }
1146 
1147   // GC support
1148   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1149     if (has_arguments()) {
1150       _args.clean_weak_klass_links(is_alive_closure);
1151     }
1152     if (has_return()) {
1153       _ret.clean_weak_klass_links(is_alive_closure);
1154     }
1155   }
1156 
1157   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1158 };
1159 
1160 // ReceiverTypeData
1161 //
1162 // A ReceiverTypeData is used to access profiling information about a
1163 // dynamic type check.  It consists of a counter which counts the total times
1164 // that the check is reached, and a series of (Klass*, count) pairs
1165 // which are used to store a type profile for the receiver of the check.
1166 class ReceiverTypeData : public CounterData {
1167 protected:
1168   enum {
1169     receiver0_offset = counter_cell_count,
1170     count0_offset,
1171     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
1172   };
1173 
1174 public:
1175   ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
1176     assert(layout->tag() == DataLayout::receiver_type_data_tag ||
1177            layout->tag() == DataLayout::virtual_call_data_tag ||
1178            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1179   }
1180 
1181   virtual bool is_ReceiverTypeData() const { return true; }
1182 
1183   static int static_cell_count() {
1184     return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
1185   }
1186 
1187   virtual int cell_count() const {
1188     return static_cell_count();
1189   }
1190 
1191   // Direct accessors
1192   static uint row_limit() {
1193     return TypeProfileWidth;
1194   }
1195   static int receiver_cell_index(uint row) {
1196     return receiver0_offset + row * receiver_type_row_cell_count;
1197   }
1198   static int receiver_count_cell_index(uint row) {
1199     return count0_offset + row * receiver_type_row_cell_count;
1200   }
1201 
1202   Klass* receiver(uint row) const {
1203     assert(row < row_limit(), "oob");
1204 
1205     Klass* recv = (Klass*)intptr_at(receiver_cell_index(row));
1206     assert(recv == NULL || recv->is_klass(), "wrong type");
1207     return recv;
1208   }
1209 
1210   void set_receiver(uint row, Klass* k) {
1211     assert((uint)row < row_limit(), "oob");
1212     set_intptr_at(receiver_cell_index(row), (uintptr_t)k);
1213   }
1214 
1215   uint receiver_count(uint row) const {
1216     assert(row < row_limit(), "oob");
1217     return uint_at(receiver_count_cell_index(row));
1218   }
1219 
1220   void set_receiver_count(uint row, uint count) {
1221     assert(row < row_limit(), "oob");
1222     set_uint_at(receiver_count_cell_index(row), count);
1223   }
1224 
1225   void clear_row(uint row) {
1226     assert(row < row_limit(), "oob");
1227     // Clear total count - indicator of polymorphic call site.
1228     // The site may look like as monomorphic after that but
1229     // it allow to have more accurate profiling information because
1230     // there was execution phase change since klasses were unloaded.
1231     // If the site is still polymorphic then MDO will be updated
1232     // to reflect it. But it could be the case that the site becomes
1233     // only bimorphic. Then keeping total count not 0 will be wrong.
1234     // Even if we use monomorphic (when it is not) for compilation
1235     // we will only have trap, deoptimization and recompile again
1236     // with updated MDO after executing method in Interpreter.
1237     // An additional receiver will be recorded in the cleaned row
1238     // during next call execution.
1239     //
1240     // Note: our profiling logic works with empty rows in any slot.
1241     // We do sorting a profiling info (ciCallProfile) for compilation.
1242     //
1243     set_count(0);
1244     set_receiver(row, NULL);
1245     set_receiver_count(row, 0);
1246   }
1247 
1248   // Code generation support
1249   static ByteSize receiver_offset(uint row) {
1250     return cell_offset(receiver_cell_index(row));
1251   }
1252   static ByteSize receiver_count_offset(uint row) {
1253     return cell_offset(receiver_count_cell_index(row));
1254   }
1255   static ByteSize receiver_type_data_size() {
1256     return cell_offset(static_cell_count());
1257   }
1258 
1259   // GC support
1260   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
1261 
1262 #ifdef CC_INTERP
1263   static int receiver_type_data_size_in_bytes() {
1264     return cell_offset_in_bytes(static_cell_count());
1265   }
1266 
1267   static Klass *receiver_unchecked(DataLayout* layout, uint row) {
1268     Klass* recv = (Klass*)layout->cell_at(receiver_cell_index(row));
1269     return recv;
1270   }
1271 
1272   static void increment_receiver_count_no_overflow(DataLayout* layout, Klass *rcvr) {
1273     const int num_rows = row_limit();
1274     // Receiver already exists?
1275     for (int row = 0; row < num_rows; row++) {
1276       if (receiver_unchecked(layout, row) == rcvr) {
1277         increment_uint_at_no_overflow(layout, receiver_count_cell_index(row));
1278         return;
1279       }
1280     }
1281     // New receiver, find a free slot.
1282     for (int row = 0; row < num_rows; row++) {
1283       if (receiver_unchecked(layout, row) == NULL) {
1284         set_intptr_at(layout, receiver_cell_index(row), (intptr_t)rcvr);
1285         increment_uint_at_no_overflow(layout, receiver_count_cell_index(row));
1286         return;
1287       }
1288     }
1289     // Receiver did not match any saved receiver and there is no empty row for it.
1290     // Increment total counter to indicate polymorphic case.
1291     increment_count_no_overflow(layout);
1292   }
1293 
1294   static DataLayout* advance(DataLayout* layout) {
1295     return (DataLayout*) (((address)layout) + (ssize_t)ReceiverTypeData::receiver_type_data_size_in_bytes());
1296   }
1297 #endif // CC_INTERP
1298 
1299   void print_receiver_data_on(outputStream* st) const;
1300   void print_data_on(outputStream* st, const char* extra = NULL) const;
1301 };
1302 
1303 // VirtualCallData
1304 //
1305 // A VirtualCallData is used to access profiling information about a
1306 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
1307 class VirtualCallData : public ReceiverTypeData {
1308 public:
1309   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
1310     assert(layout->tag() == DataLayout::virtual_call_data_tag ||
1311            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1312   }
1313 
1314   virtual bool is_VirtualCallData() const { return true; }
1315 
1316   static int static_cell_count() {
1317     // At this point we could add more profile state, e.g., for arguments.
1318     // But for now it's the same size as the base record type.
1319     return ReceiverTypeData::static_cell_count();
1320   }
1321 
1322   virtual int cell_count() const {
1323     return static_cell_count();
1324   }
1325 
1326   // Direct accessors
1327   static ByteSize virtual_call_data_size() {
1328     return cell_offset(static_cell_count());
1329   }
1330 
1331 #ifdef CC_INTERP
1332   static int virtual_call_data_size_in_bytes() {
1333     return cell_offset_in_bytes(static_cell_count());
1334   }
1335 
1336   static DataLayout* advance(DataLayout* layout) {
1337     return (DataLayout*) (((address)layout) + (ssize_t)VirtualCallData::virtual_call_data_size_in_bytes());
1338   }
1339 #endif // CC_INTERP
1340 
1341   void print_data_on(outputStream* st, const char* extra = NULL) const;
1342 };
1343 
1344 // VirtualCallTypeData
1345 //
1346 // A VirtualCallTypeData is used to access profiling information about
1347 // a virtual call for which we collect type information about
1348 // arguments and return value.
1349 class VirtualCallTypeData : public VirtualCallData {
1350 private:
1351   // entries for arguments if any
1352   TypeStackSlotEntries _args;
1353   // entry for return type if any
1354   ReturnTypeEntry _ret;
1355 
1356   int cell_count_global_offset() const {
1357     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
1358   }
1359 
1360   // number of cells not counting the header
1361   int cell_count_no_header() const {
1362     return uint_at(cell_count_global_offset());
1363   }
1364 
1365   void check_number_of_arguments(int total) {
1366     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
1367   }
1368 
1369 public:
1370   VirtualCallTypeData(DataLayout* layout) :
1371     VirtualCallData(layout),
1372     _args(VirtualCallData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
1373     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
1374   {
1375     assert(layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
1376     // Some compilers (VC++) don't want this passed in member initialization list
1377     _args.set_profile_data(this);
1378     _ret.set_profile_data(this);
1379   }
1380 
1381   const TypeStackSlotEntries* args() const {
1382     assert(has_arguments(), "no profiling of arguments");
1383     return &_args;
1384   }
1385 
1386   const ReturnTypeEntry* ret() const {
1387     assert(has_return(), "no profiling of return value");
1388     return &_ret;
1389   }
1390 
1391   virtual bool is_VirtualCallTypeData() const { return true; }
1392 
1393   static int static_cell_count() {
1394     return -1;
1395   }
1396 
1397   static int compute_cell_count(BytecodeStream* stream) {
1398     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
1399   }
1400 
1401   static void initialize(DataLayout* dl, int cell_count) {
1402     TypeEntriesAtCall::initialize(dl, VirtualCallData::static_cell_count(), cell_count);
1403   }
1404 
1405   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1406 
1407   virtual int cell_count() const {
1408     return VirtualCallData::static_cell_count() +
1409       TypeEntriesAtCall::header_cell_count() +
1410       int_at_unchecked(cell_count_global_offset());
1411   }
1412 
1413   int number_of_arguments() const {
1414     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
1415   }
1416 
1417   void set_argument_type(int i, Klass* k) {
1418     assert(has_arguments(), "no arguments!");
1419     intptr_t current = _args.type(i);
1420     _args.set_type(i, TypeEntries::with_status(k, current));
1421   }
1422 
1423   void set_return_type(Klass* k) {
1424     assert(has_return(), "no return!");
1425     intptr_t current = _ret.type();
1426     _ret.set_type(TypeEntries::with_status(k, current));
1427   }
1428 
1429   // An entry for a return value takes less space than an entry for an
1430   // argument, so if the remainder of the number of cells divided by
1431   // the number of cells for an argument is not null, a return value
1432   // is profiled in this object.
1433   bool has_return() const {
1434     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
1435     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
1436     return res;
1437   }
1438 
1439   // An entry for a return value takes less space than an entry for an
1440   // argument so if the number of cells exceeds the number of cells
1441   // needed for an argument, this object contains type information for
1442   // at least one argument.
1443   bool has_arguments() const {
1444     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
1445     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
1446     return res;
1447   }
1448 
1449   // Code generation support
1450   static ByteSize args_data_offset() {
1451     return cell_offset(VirtualCallData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
1452   }
1453 
1454   ByteSize argument_type_offset(int i) {
1455     return _args.type_offset(i);
1456   }
1457 
1458   ByteSize return_type_offset() {
1459     return _ret.type_offset();
1460   }
1461 
1462   // GC support
1463   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1464     ReceiverTypeData::clean_weak_klass_links(is_alive_closure);
1465     if (has_arguments()) {
1466       _args.clean_weak_klass_links(is_alive_closure);
1467     }
1468     if (has_return()) {
1469       _ret.clean_weak_klass_links(is_alive_closure);
1470     }
1471   }
1472 
1473   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1474 };
1475 
1476 // RetData
1477 //
1478 // A RetData is used to access profiling information for a ret bytecode.
1479 // It is composed of a count of the number of times that the ret has
1480 // been executed, followed by a series of triples of the form
1481 // (bci, count, di) which count the number of times that some bci was the
1482 // target of the ret and cache a corresponding data displacement.
1483 class RetData : public CounterData {
1484 protected:
1485   enum {
1486     bci0_offset = counter_cell_count,
1487     count0_offset,
1488     displacement0_offset,
1489     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
1490   };
1491 
1492   void set_bci(uint row, int bci) {
1493     assert((uint)row < row_limit(), "oob");
1494     set_int_at(bci0_offset + row * ret_row_cell_count, bci);
1495   }
1496   void release_set_bci(uint row, int bci) {
1497     assert((uint)row < row_limit(), "oob");
1498     // 'release' when setting the bci acts as a valid flag for other
1499     // threads wrt bci_count and bci_displacement.
1500     release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
1501   }
1502   void set_bci_count(uint row, uint count) {
1503     assert((uint)row < row_limit(), "oob");
1504     set_uint_at(count0_offset + row * ret_row_cell_count, count);
1505   }
1506   void set_bci_displacement(uint row, int disp) {
1507     set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
1508   }
1509 
1510 public:
1511   RetData(DataLayout* layout) : CounterData(layout) {
1512     assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
1513   }
1514 
1515   virtual bool is_RetData() const { return true; }
1516 
1517   enum {
1518     no_bci = -1 // value of bci when bci1/2 are not in use.
1519   };
1520 
1521   static int static_cell_count() {
1522     return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
1523   }
1524 
1525   virtual int cell_count() const {
1526     return static_cell_count();
1527   }
1528 
1529   static uint row_limit() {
1530     return BciProfileWidth;
1531   }
1532   static int bci_cell_index(uint row) {
1533     return bci0_offset + row * ret_row_cell_count;
1534   }
1535   static int bci_count_cell_index(uint row) {
1536     return count0_offset + row * ret_row_cell_count;
1537   }
1538   static int bci_displacement_cell_index(uint row) {
1539     return displacement0_offset + row * ret_row_cell_count;
1540   }
1541 
1542   // Direct accessors
1543   int bci(uint row) const {
1544     return int_at(bci_cell_index(row));
1545   }
1546   uint bci_count(uint row) const {
1547     return uint_at(bci_count_cell_index(row));
1548   }
1549   int bci_displacement(uint row) const {
1550     return int_at(bci_displacement_cell_index(row));
1551   }
1552 
1553   // Interpreter Runtime support
1554   address fixup_ret(int return_bci, MethodData* mdo);
1555 
1556   // Code generation support
1557   static ByteSize bci_offset(uint row) {
1558     return cell_offset(bci_cell_index(row));
1559   }
1560   static ByteSize bci_count_offset(uint row) {
1561     return cell_offset(bci_count_cell_index(row));
1562   }
1563   static ByteSize bci_displacement_offset(uint row) {
1564     return cell_offset(bci_displacement_cell_index(row));
1565   }
1566 
1567 #ifdef CC_INTERP
1568   static DataLayout* advance(MethodData *md, int bci);
1569 #endif // CC_INTERP
1570 
1571   // Specific initialization.
1572   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1573 
1574   void print_data_on(outputStream* st, const char* extra = NULL) const;
1575 };
1576 
1577 // BranchData
1578 //
1579 // A BranchData is used to access profiling data for a two-way branch.
1580 // It consists of taken and not_taken counts as well as a data displacement
1581 // for the taken case.
1582 class BranchData : public JumpData {
1583 protected:
1584   enum {
1585     not_taken_off_set = jump_cell_count,
1586     branch_cell_count
1587   };
1588 
1589   void set_displacement(int displacement) {
1590     set_int_at(displacement_off_set, displacement);
1591   }
1592 
1593 public:
1594   BranchData(DataLayout* layout) : JumpData(layout) {
1595     assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
1596   }
1597 
1598   virtual bool is_BranchData() const { return true; }
1599 
1600   static int static_cell_count() {
1601     return branch_cell_count;
1602   }
1603 
1604   virtual int cell_count() const {
1605     return static_cell_count();
1606   }
1607 
1608   // Direct accessor
1609   uint not_taken() const {
1610     return uint_at(not_taken_off_set);
1611   }
1612 
1613   void set_not_taken(uint cnt) {
1614     set_uint_at(not_taken_off_set, cnt);
1615   }
1616 
1617   uint inc_not_taken() {
1618     uint cnt = not_taken() + 1;
1619     // Did we wrap? Will compiler screw us??
1620     if (cnt == 0) cnt--;
1621     set_uint_at(not_taken_off_set, cnt);
1622     return cnt;
1623   }
1624 
1625   // Code generation support
1626   static ByteSize not_taken_offset() {
1627     return cell_offset(not_taken_off_set);
1628   }
1629   static ByteSize branch_data_size() {
1630     return cell_offset(branch_cell_count);
1631   }
1632 
1633 #ifdef CC_INTERP
1634   static int branch_data_size_in_bytes() {
1635     return cell_offset_in_bytes(branch_cell_count);
1636   }
1637 
1638   static void increment_not_taken_count_no_overflow(DataLayout* layout) {
1639     increment_uint_at_no_overflow(layout, not_taken_off_set);
1640   }
1641 
1642   static DataLayout* advance_not_taken(DataLayout* layout) {
1643     return (DataLayout*) (((address)layout) + (ssize_t)BranchData::branch_data_size_in_bytes());
1644   }
1645 #endif // CC_INTERP
1646 
1647   // Specific initialization.
1648   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1649 
1650   void print_data_on(outputStream* st, const char* extra = NULL) const;
1651 };
1652 
1653 // ArrayData
1654 //
1655 // A ArrayData is a base class for accessing profiling data which does
1656 // not have a statically known size.  It consists of an array length
1657 // and an array start.
1658 class ArrayData : public ProfileData {
1659 protected:
1660   friend class DataLayout;
1661 
1662   enum {
1663     array_len_off_set,
1664     array_start_off_set
1665   };
1666 
1667   uint array_uint_at(int index) const {
1668     int aindex = index + array_start_off_set;
1669     return uint_at(aindex);
1670   }
1671   int array_int_at(int index) const {
1672     int aindex = index + array_start_off_set;
1673     return int_at(aindex);
1674   }
1675   oop array_oop_at(int index) const {
1676     int aindex = index + array_start_off_set;
1677     return oop_at(aindex);
1678   }
1679   void array_set_int_at(int index, int value) {
1680     int aindex = index + array_start_off_set;
1681     set_int_at(aindex, value);
1682   }
1683 
1684 #ifdef CC_INTERP
1685   // Static low level accessors for DataLayout with ArrayData's semantics.
1686 
1687   static void increment_array_uint_at_no_overflow(DataLayout* layout, int index) {
1688     int aindex = index + array_start_off_set;
1689     increment_uint_at_no_overflow(layout, aindex);
1690   }
1691 
1692   static int array_int_at(DataLayout* layout, int index) {
1693     int aindex = index + array_start_off_set;
1694     return int_at(layout, aindex);
1695   }
1696 #endif // CC_INTERP
1697 
1698   // Code generation support for subclasses.
1699   static ByteSize array_element_offset(int index) {
1700     return cell_offset(array_start_off_set + index);
1701   }
1702 
1703 public:
1704   ArrayData(DataLayout* layout) : ProfileData(layout) {}
1705 
1706   virtual bool is_ArrayData() const { return true; }
1707 
1708   static int static_cell_count() {
1709     return -1;
1710   }
1711 
1712   int array_len() const {
1713     return int_at_unchecked(array_len_off_set);
1714   }
1715 
1716   virtual int cell_count() const {
1717     return array_len() + 1;
1718   }
1719 
1720   // Code generation support
1721   static ByteSize array_len_offset() {
1722     return cell_offset(array_len_off_set);
1723   }
1724   static ByteSize array_start_offset() {
1725     return cell_offset(array_start_off_set);
1726   }
1727 };
1728 
1729 // MultiBranchData
1730 //
1731 // A MultiBranchData is used to access profiling information for
1732 // a multi-way branch (*switch bytecodes).  It consists of a series
1733 // of (count, displacement) pairs, which count the number of times each
1734 // case was taken and specify the data displacment for each branch target.
1735 class MultiBranchData : public ArrayData {
1736 protected:
1737   enum {
1738     default_count_off_set,
1739     default_disaplacement_off_set,
1740     case_array_start
1741   };
1742   enum {
1743     relative_count_off_set,
1744     relative_displacement_off_set,
1745     per_case_cell_count
1746   };
1747 
1748   void set_default_displacement(int displacement) {
1749     array_set_int_at(default_disaplacement_off_set, displacement);
1750   }
1751   void set_displacement_at(int index, int displacement) {
1752     array_set_int_at(case_array_start +
1753                      index * per_case_cell_count +
1754                      relative_displacement_off_set,
1755                      displacement);
1756   }
1757 
1758 public:
1759   MultiBranchData(DataLayout* layout) : ArrayData(layout) {
1760     assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
1761   }
1762 
1763   virtual bool is_MultiBranchData() const { return true; }
1764 
1765   static int compute_cell_count(BytecodeStream* stream);
1766 
1767   int number_of_cases() const {
1768     int alen = array_len() - 2; // get rid of default case here.
1769     assert(alen % per_case_cell_count == 0, "must be even");
1770     return (alen / per_case_cell_count);
1771   }
1772 
1773   uint default_count() const {
1774     return array_uint_at(default_count_off_set);
1775   }
1776   int default_displacement() const {
1777     return array_int_at(default_disaplacement_off_set);
1778   }
1779 
1780   uint count_at(int index) const {
1781     return array_uint_at(case_array_start +
1782                          index * per_case_cell_count +
1783                          relative_count_off_set);
1784   }
1785   int displacement_at(int index) const {
1786     return array_int_at(case_array_start +
1787                         index * per_case_cell_count +
1788                         relative_displacement_off_set);
1789   }
1790 
1791   // Code generation support
1792   static ByteSize default_count_offset() {
1793     return array_element_offset(default_count_off_set);
1794   }
1795   static ByteSize default_displacement_offset() {
1796     return array_element_offset(default_disaplacement_off_set);
1797   }
1798   static ByteSize case_count_offset(int index) {
1799     return case_array_offset() +
1800            (per_case_size() * index) +
1801            relative_count_offset();
1802   }
1803   static ByteSize case_array_offset() {
1804     return array_element_offset(case_array_start);
1805   }
1806   static ByteSize per_case_size() {
1807     return in_ByteSize(per_case_cell_count) * cell_size;
1808   }
1809   static ByteSize relative_count_offset() {
1810     return in_ByteSize(relative_count_off_set) * cell_size;
1811   }
1812   static ByteSize relative_displacement_offset() {
1813     return in_ByteSize(relative_displacement_off_set) * cell_size;
1814   }
1815 
1816 #ifdef CC_INTERP
1817   static void increment_count_no_overflow(DataLayout* layout, int index) {
1818     if (index == -1) {
1819       increment_array_uint_at_no_overflow(layout, default_count_off_set);
1820     } else {
1821       increment_array_uint_at_no_overflow(layout, case_array_start +
1822                                                   index * per_case_cell_count +
1823                                                   relative_count_off_set);
1824     }
1825   }
1826 
1827   static DataLayout* advance(DataLayout* layout, int index) {
1828     if (index == -1) {
1829       return (DataLayout*) (((address)layout) + (ssize_t)array_int_at(layout, default_disaplacement_off_set));
1830     } else {
1831       return (DataLayout*) (((address)layout) + (ssize_t)array_int_at(layout, case_array_start +
1832                                                                               index * per_case_cell_count +
1833                                                                               relative_displacement_off_set));
1834     }
1835   }
1836 #endif // CC_INTERP
1837 
1838   // Specific initialization.
1839   void post_initialize(BytecodeStream* stream, MethodData* mdo);
1840 
1841   void print_data_on(outputStream* st, const char* extra = NULL) const;
1842 };
1843 
1844 class ArgInfoData : public ArrayData {
1845 
1846 public:
1847   ArgInfoData(DataLayout* layout) : ArrayData(layout) {
1848     assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
1849   }
1850 
1851   virtual bool is_ArgInfoData() const { return true; }
1852 
1853 
1854   int number_of_args() const {
1855     return array_len();
1856   }
1857 
1858   uint arg_modified(int arg) const {
1859     return array_uint_at(arg);
1860   }
1861 
1862   void set_arg_modified(int arg, uint val) {
1863     array_set_int_at(arg, val);
1864   }
1865 
1866   void print_data_on(outputStream* st, const char* extra = NULL) const;
1867 };
1868 
1869 // ParametersTypeData
1870 //
1871 // A ParametersTypeData is used to access profiling information about
1872 // types of parameters to a method
1873 class ParametersTypeData : public ArrayData {
1874 
1875 private:
1876   TypeStackSlotEntries _parameters;
1877 
1878   static int stack_slot_local_offset(int i) {
1879     assert_profiling_enabled();
1880     return array_start_off_set + TypeStackSlotEntries::stack_slot_local_offset(i);
1881   }
1882 
1883   static int type_local_offset(int i) {
1884     assert_profiling_enabled();
1885     return array_start_off_set + TypeStackSlotEntries::type_local_offset(i);
1886   }
1887 
1888   static bool profiling_enabled();
1889   static void assert_profiling_enabled() {
1890     assert(profiling_enabled(), "method parameters profiling should be on");
1891   }
1892 
1893 public:
1894   ParametersTypeData(DataLayout* layout) : ArrayData(layout), _parameters(1, number_of_parameters()) {
1895     assert(layout->tag() == DataLayout::parameters_type_data_tag, "wrong type");
1896     // Some compilers (VC++) don't want this passed in member initialization list
1897     _parameters.set_profile_data(this);
1898   }
1899 
1900   static int compute_cell_count(Method* m);
1901 
1902   virtual bool is_ParametersTypeData() const { return true; }
1903 
1904   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
1905 
1906   int number_of_parameters() const {
1907     return array_len() / TypeStackSlotEntries::per_arg_count();
1908   }
1909 
1910   const TypeStackSlotEntries* parameters() const { return &_parameters; }
1911 
1912   uint stack_slot(int i) const {
1913     return _parameters.stack_slot(i);
1914   }
1915 
1916   void set_type(int i, Klass* k) {
1917     intptr_t current = _parameters.type(i);
1918     _parameters.set_type(i, TypeEntries::with_status((intptr_t)k, current));
1919   }
1920 
1921   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
1922     _parameters.clean_weak_klass_links(is_alive_closure);
1923   }
1924 
1925   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1926 
1927   static ByteSize stack_slot_offset(int i) {
1928     return cell_offset(stack_slot_local_offset(i));
1929   }
1930 
1931   static ByteSize type_offset(int i) {
1932     return cell_offset(type_local_offset(i));
1933   }
1934 };
1935 
1936 // SpeculativeTrapData
1937 //
1938 // A SpeculativeTrapData is used to record traps due to type
1939 // speculation. It records the root of the compilation: that type
1940 // speculation is wrong in the context of one compilation (for
1941 // method1) doesn't mean it's wrong in the context of another one (for
1942 // method2). Type speculation could have more/different data in the
1943 // context of the compilation of method2 and it's worthwhile to try an
1944 // optimization that failed for compilation of method1 in the context
1945 // of compilation of method2.
1946 // Space for SpeculativeTrapData entries is allocated from the extra
1947 // data space in the MDO. If we run out of space, the trap data for
1948 // the ProfileData at that bci is updated.
1949 class SpeculativeTrapData : public ProfileData {
1950 protected:
1951   enum {
1952     speculative_trap_method,
1953     speculative_trap_cell_count
1954   };
1955 public:
1956   SpeculativeTrapData(DataLayout* layout) : ProfileData(layout) {
1957     assert(layout->tag() == DataLayout::speculative_trap_data_tag, "wrong type");
1958   }
1959 
1960   virtual bool is_SpeculativeTrapData() const { return true; }
1961 
1962   static int static_cell_count() {
1963     return speculative_trap_cell_count;
1964   }
1965 
1966   virtual int cell_count() const {
1967     return static_cell_count();
1968   }
1969 
1970   // Direct accessor
1971   Method* method() const {
1972     return (Method*)intptr_at(speculative_trap_method);
1973   }
1974 
1975   void set_method(Method* m) {
1976     assert(!m->is_old(), "cannot add old methods");
1977     set_intptr_at(speculative_trap_method, (intptr_t)m);
1978   }
1979 
1980   static ByteSize method_offset() {
1981     return cell_offset(speculative_trap_method);
1982   }
1983 
1984   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
1985 };
1986 
1987 // MethodData*
1988 //
1989 // A MethodData* holds information which has been collected about
1990 // a method.  Its layout looks like this:
1991 //
1992 // -----------------------------
1993 // | header                    |
1994 // | klass                     |
1995 // -----------------------------
1996 // | method                    |
1997 // | size of the MethodData* |
1998 // -----------------------------
1999 // | Data entries...           |
2000 // |   (variable size)         |
2001 // |                           |
2002 // .                           .
2003 // .                           .
2004 // .                           .
2005 // |                           |
2006 // -----------------------------
2007 //
2008 // The data entry area is a heterogeneous array of DataLayouts. Each
2009 // DataLayout in the array corresponds to a specific bytecode in the
2010 // method.  The entries in the array are sorted by the corresponding
2011 // bytecode.  Access to the data is via resource-allocated ProfileData,
2012 // which point to the underlying blocks of DataLayout structures.
2013 //
2014 // During interpretation, if profiling in enabled, the interpreter
2015 // maintains a method data pointer (mdp), which points at the entry
2016 // in the array corresponding to the current bci.  In the course of
2017 // intepretation, when a bytecode is encountered that has profile data
2018 // associated with it, the entry pointed to by mdp is updated, then the
2019 // mdp is adjusted to point to the next appropriate DataLayout.  If mdp
2020 // is NULL to begin with, the interpreter assumes that the current method
2021 // is not (yet) being profiled.
2022 //
2023 // In MethodData* parlance, "dp" is a "data pointer", the actual address
2024 // of a DataLayout element.  A "di" is a "data index", the offset in bytes
2025 // from the base of the data entry array.  A "displacement" is the byte offset
2026 // in certain ProfileData objects that indicate the amount the mdp must be
2027 // adjusted in the event of a change in control flow.
2028 //
2029 
2030 CC_INTERP_ONLY(class BytecodeInterpreter;)
2031 class CleanExtraDataClosure;
2032 
2033 class MethodData : public Metadata {
2034   friend class VMStructs;
2035   CC_INTERP_ONLY(friend class BytecodeInterpreter;)
2036 private:
2037   friend class ProfileData;
2038 
2039   // Back pointer to the Method*
2040   Method* _method;
2041 
2042   // Size of this oop in bytes
2043   int _size;
2044 
2045   // Cached hint for bci_to_dp and bci_to_data
2046   int _hint_di;
2047 
2048   Mutex _extra_data_lock;
2049 
2050   MethodData(methodHandle method, int size, TRAPS);
2051 public:
2052   static MethodData* allocate(ClassLoaderData* loader_data, methodHandle method, TRAPS);
2053   MethodData() : _extra_data_lock(Monitor::leaf, "MDO extra data lock") {}; // For ciMethodData
2054 
2055   bool is_methodData() const volatile { return true; }
2056 
2057   // Whole-method sticky bits and flags
2058   enum {
2059     _trap_hist_limit    = 21,   // decoupled from Deoptimization::Reason_LIMIT
2060     _trap_hist_mask     = max_jubyte,
2061     _extra_data_count   = 4     // extra DataLayout headers, for trap history
2062   }; // Public flag values
2063 private:
2064   uint _nof_decompiles;             // count of all nmethod removals
2065   uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
2066   uint _nof_overflow_traps;         // trap count, excluding _trap_hist
2067   union {
2068     intptr_t _align;
2069     u1 _array[_trap_hist_limit];
2070   } _trap_hist;
2071 
2072   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2073   intx              _eflags;          // flags on escape information
2074   intx              _arg_local;       // bit set of non-escaping arguments
2075   intx              _arg_stack;       // bit set of stack-allocatable arguments
2076   intx              _arg_returned;    // bit set of returned arguments
2077 
2078   int _creation_mileage;              // method mileage at MDO creation
2079 
2080   // How many invocations has this MDO seen?
2081   // These counters are used to determine the exact age of MDO.
2082   // We need those because in tiered a method can be concurrently
2083   // executed at different levels.
2084   InvocationCounter _invocation_counter;
2085   // Same for backedges.
2086   InvocationCounter _backedge_counter;
2087   // Counter values at the time profiling started.
2088   int               _invocation_counter_start;
2089   int               _backedge_counter_start;
2090   uint              _tenure_traps;
2091   int               _invoke_mask;      // per-method Tier0InvokeNotifyFreqLog
2092   int               _backedge_mask;    // per-method Tier0BackedgeNotifyFreqLog
2093 
2094 #if INCLUDE_RTM_OPT
2095   // State of RTM code generation during compilation of the method
2096   int               _rtm_state;
2097 #endif
2098 
2099   // Number of loops and blocks is computed when compiling the first
2100   // time with C1. It is used to determine if method is trivial.
2101   short             _num_loops;
2102   short             _num_blocks;
2103   // Does this method contain anything worth profiling?
2104   enum WouldProfile {unknown, no_profile, profile};
2105   WouldProfile      _would_profile;
2106 
2107   // Size of _data array in bytes.  (Excludes header and extra_data fields.)
2108   int _data_size;
2109 
2110   // data index for the area dedicated to parameters. -1 if no
2111   // parameter profiling.
2112   enum { no_parameters = -2, parameters_uninitialized = -1 };
2113   int _parameters_type_data_di;
2114   int parameters_size_in_bytes() const {
2115     ParametersTypeData* param = parameters_type_data();
2116     return param == NULL ? 0 : param->size_in_bytes();
2117   }
2118 
2119   // Beginning of the data entries
2120   intptr_t _data[1];
2121 
2122   // Helper for size computation
2123   static int compute_data_size(BytecodeStream* stream);
2124   static int bytecode_cell_count(Bytecodes::Code code);
2125   static bool is_speculative_trap_bytecode(Bytecodes::Code code);
2126   enum { no_profile_data = -1, variable_cell_count = -2 };
2127 
2128   // Helper for initialization
2129   DataLayout* data_layout_at(int data_index) const {
2130     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
2131     return (DataLayout*) (((address)_data) + data_index);
2132   }
2133 
2134   // Initialize an individual data segment.  Returns the size of
2135   // the segment in bytes.
2136   int initialize_data(BytecodeStream* stream, int data_index);
2137 
2138   // Helper for data_at
2139   DataLayout* limit_data_position() const {
2140     return data_layout_at(_data_size);
2141   }
2142   bool out_of_bounds(int data_index) const {
2143     return data_index >= data_size();
2144   }
2145 
2146   // Give each of the data entries a chance to perform specific
2147   // data initialization.
2148   void post_initialize(BytecodeStream* stream);
2149 
2150   // hint accessors
2151   int      hint_di() const  { return _hint_di; }
2152   void set_hint_di(int di)  {
2153     assert(!out_of_bounds(di), "hint_di out of bounds");
2154     _hint_di = di;
2155   }
2156   ProfileData* data_before(int bci) {
2157     // avoid SEGV on this edge case
2158     if (data_size() == 0)
2159       return NULL;
2160     int hint = hint_di();
2161     if (data_layout_at(hint)->bci() <= bci)
2162       return data_at(hint);
2163     return first_data();
2164   }
2165 
2166   // What is the index of the first data entry?
2167   int first_di() const { return 0; }
2168 
2169   ProfileData* bci_to_extra_data_helper(int bci, Method* m, DataLayout*& dp, bool concurrent);
2170   // Find or create an extra ProfileData:
2171   ProfileData* bci_to_extra_data(int bci, Method* m, bool create_if_missing);
2172 
2173   // return the argument info cell
2174   ArgInfoData *arg_info();
2175 
2176   enum {
2177     no_type_profile = 0,
2178     type_profile_jsr292 = 1,
2179     type_profile_all = 2
2180   };
2181 
2182   static bool profile_jsr292(methodHandle m, int bci);
2183   static int profile_arguments_flag();
2184   static bool profile_all_arguments();
2185   static bool profile_arguments_for_invoke(methodHandle m, int bci);
2186   static int profile_return_flag();
2187   static bool profile_all_return();
2188   static bool profile_return_for_invoke(methodHandle m, int bci);
2189   static int profile_parameters_flag();
2190   static bool profile_parameters_jsr292_only();
2191   static bool profile_all_parameters();
2192 
2193   void clean_extra_data(CleanExtraDataClosure* cl);
2194   void clean_extra_data_helper(DataLayout* dp, int shift, bool reset = false);
2195   void verify_extra_data_clean(CleanExtraDataClosure* cl);
2196 
2197 public:
2198   static int header_size() {
2199     return sizeof(MethodData)/wordSize;
2200   }
2201 
2202   // Compute the size of a MethodData* before it is created.
2203   static int compute_allocation_size_in_bytes(methodHandle method);
2204   static int compute_allocation_size_in_words(methodHandle method);
2205   static int compute_extra_data_count(int data_size, int empty_bc_count, bool needs_speculative_traps);
2206 
2207   // Determine if a given bytecode can have profile information.
2208   static bool bytecode_has_profile(Bytecodes::Code code) {
2209     return bytecode_cell_count(code) != no_profile_data;
2210   }
2211 
2212   // reset into original state
2213   void init();
2214 
2215   // My size
2216   int size_in_bytes() const { return _size; }
2217   int size() const    { return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord); }
2218 #if INCLUDE_SERVICES
2219   void collect_statistics(KlassSizeStats *sz) const;
2220 #endif
2221 
2222   int      creation_mileage() const  { return _creation_mileage; }
2223   void set_creation_mileage(int x)   { _creation_mileage = x; }
2224 
2225   int invocation_count() {
2226     if (invocation_counter()->carry()) {
2227       return InvocationCounter::count_limit;
2228     }
2229     return invocation_counter()->count();
2230   }
2231   int backedge_count() {
2232     if (backedge_counter()->carry()) {
2233       return InvocationCounter::count_limit;
2234     }
2235     return backedge_counter()->count();
2236   }
2237 
2238   int invocation_count_start() {
2239     if (invocation_counter()->carry()) {
2240       return 0;
2241     }
2242     return _invocation_counter_start;
2243   }
2244 
2245   int backedge_count_start() {
2246     if (backedge_counter()->carry()) {
2247       return 0;
2248     }
2249     return _backedge_counter_start;
2250   }
2251 
2252   int invocation_count_delta() { return invocation_count() - invocation_count_start(); }
2253   int backedge_count_delta()   { return backedge_count()   - backedge_count_start();   }
2254 
2255   void reset_start_counters() {
2256     _invocation_counter_start = invocation_count();
2257     _backedge_counter_start = backedge_count();
2258   }
2259 
2260   InvocationCounter* invocation_counter()     { return &_invocation_counter; }
2261   InvocationCounter* backedge_counter()       { return &_backedge_counter;   }
2262 
2263 #if INCLUDE_RTM_OPT
2264   int rtm_state() const {
2265     return _rtm_state;
2266   }
2267   void set_rtm_state(RTMState rstate) {
2268     _rtm_state = (int)rstate;
2269   }
2270   void atomic_set_rtm_state(RTMState rstate) {
2271     Atomic::store((int)rstate, &_rtm_state);
2272   }
2273 
2274   static int rtm_state_offset_in_bytes() {
2275     return offset_of(MethodData, _rtm_state);
2276   }
2277 #endif
2278 
2279   void set_would_profile(bool p)              { _would_profile = p ? profile : no_profile; }
2280   bool would_profile() const                  { return _would_profile != no_profile; }
2281 
2282   int num_loops() const                       { return _num_loops;  }
2283   void set_num_loops(int n)                   { _num_loops = n;     }
2284   int num_blocks() const                      { return _num_blocks; }
2285   void set_num_blocks(int n)                  { _num_blocks = n;    }
2286 
2287   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
2288   static int mileage_of(Method* m);
2289 
2290   // Support for interprocedural escape analysis, from Thomas Kotzmann.
2291   enum EscapeFlag {
2292     estimated    = 1 << 0,
2293     return_local = 1 << 1,
2294     return_allocated = 1 << 2,
2295     allocated_escapes = 1 << 3,
2296     unknown_modified = 1 << 4
2297   };
2298 
2299   intx eflags()                                  { return _eflags; }
2300   intx arg_local()                               { return _arg_local; }
2301   intx arg_stack()                               { return _arg_stack; }
2302   intx arg_returned()                            { return _arg_returned; }
2303   uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
2304                                                    assert(aid != NULL, "arg_info must be not null");
2305                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
2306                                                    return aid->arg_modified(a); }
2307 
2308   void set_eflags(intx v)                        { _eflags = v; }
2309   void set_arg_local(intx v)                     { _arg_local = v; }
2310   void set_arg_stack(intx v)                     { _arg_stack = v; }
2311   void set_arg_returned(intx v)                  { _arg_returned = v; }
2312   void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
2313                                                    assert(aid != NULL, "arg_info must be not null");
2314                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
2315                                                    aid->set_arg_modified(a, v); }
2316 
2317   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
2318 
2319   // Location and size of data area
2320   address data_base() const {
2321     return (address) _data;
2322   }
2323   int data_size() const {
2324     return _data_size;
2325   }
2326 
2327   // Accessors
2328   Method* method() const { return _method; }
2329 
2330   // Get the data at an arbitrary (sort of) data index.
2331   ProfileData* data_at(int data_index) const;
2332 
2333   // Walk through the data in order.
2334   ProfileData* first_data() const { return data_at(first_di()); }
2335   ProfileData* next_data(ProfileData* current) const;
2336   bool is_valid(ProfileData* current) const { return current != NULL; }
2337 
2338   // Convert a dp (data pointer) to a di (data index).
2339   int dp_to_di(address dp) const {
2340     return dp - ((address)_data);
2341   }
2342 
2343   // bci to di/dp conversion.
2344   address bci_to_dp(int bci);
2345   int bci_to_di(int bci) {
2346     return dp_to_di(bci_to_dp(bci));
2347   }
2348 
2349   // Get the data at an arbitrary bci, or NULL if there is none.
2350   ProfileData* bci_to_data(int bci);
2351 
2352   // Same, but try to create an extra_data record if one is needed:
2353   ProfileData* allocate_bci_to_data(int bci, Method* m) {
2354     ProfileData* data = NULL;
2355     // If m not NULL, try to allocate a SpeculativeTrapData entry
2356     if (m == NULL) {
2357       data = bci_to_data(bci);
2358     }
2359     if (data != NULL) {
2360       return data;
2361     }
2362     data = bci_to_extra_data(bci, m, true);
2363     if (data != NULL) {
2364       return data;
2365     }
2366     // If SpeculativeTrapData allocation fails try to allocate a
2367     // regular entry
2368     data = bci_to_data(bci);
2369     if (data != NULL) {
2370       return data;
2371     }
2372     return bci_to_extra_data(bci, NULL, true);
2373   }
2374 
2375   // Add a handful of extra data records, for trap tracking.
2376   DataLayout* extra_data_base() const  { return limit_data_position(); }
2377   DataLayout* extra_data_limit() const { return (DataLayout*)((address)this + size_in_bytes()); }
2378   DataLayout* args_data_limit() const  { return (DataLayout*)((address)this + size_in_bytes() -
2379                                                               parameters_size_in_bytes()); }
2380   int extra_data_size() const          { return (address)extra_data_limit() - (address)extra_data_base(); }
2381   static DataLayout* next_extra(DataLayout* dp);
2382 
2383   // Return (uint)-1 for overflow.
2384   uint trap_count(int reason) const {
2385     assert((uint)reason < _trap_hist_limit, "oob");
2386     return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
2387   }
2388   // For loops:
2389   static uint trap_reason_limit() { return _trap_hist_limit; }
2390   static uint trap_count_limit()  { return _trap_hist_mask; }
2391   uint inc_trap_count(int reason) {
2392     // Count another trap, anywhere in this method.
2393     assert(reason >= 0, "must be single trap");
2394     if ((uint)reason < _trap_hist_limit) {
2395       uint cnt1 = 1 + _trap_hist._array[reason];
2396       if ((cnt1 & _trap_hist_mask) != 0) {  // if no counter overflow...
2397         _trap_hist._array[reason] = cnt1;
2398         return cnt1;
2399       } else {
2400         return _trap_hist_mask + (++_nof_overflow_traps);
2401       }
2402     } else {
2403       // Could not represent the count in the histogram.
2404       return (++_nof_overflow_traps);
2405     }
2406   }
2407 
2408   uint overflow_trap_count() const {
2409     return _nof_overflow_traps;
2410   }
2411   uint overflow_recompile_count() const {
2412     return _nof_overflow_recompiles;
2413   }
2414   void inc_overflow_recompile_count() {
2415     _nof_overflow_recompiles += 1;
2416   }
2417   uint decompile_count() const {
2418     return _nof_decompiles;
2419   }
2420   void inc_decompile_count() {
2421     _nof_decompiles += 1;
2422     if (decompile_count() > (uint)PerMethodRecompilationCutoff) {
2423       method()->set_not_compilable(CompLevel_full_optimization, true, "decompile_count > PerMethodRecompilationCutoff");
2424     }
2425   }
2426   uint tenure_traps() const {
2427     return _tenure_traps;
2428   }
2429   void inc_tenure_traps() {
2430     _tenure_traps += 1;
2431   }
2432 
2433   // Return pointer to area dedicated to parameters in MDO
2434   ParametersTypeData* parameters_type_data() const {
2435     assert(_parameters_type_data_di != parameters_uninitialized, "called too early");
2436     return _parameters_type_data_di != no_parameters ? data_layout_at(_parameters_type_data_di)->data_in()->as_ParametersTypeData() : NULL;
2437   }
2438 
2439   int parameters_type_data_di() const {
2440     assert(_parameters_type_data_di != parameters_uninitialized && _parameters_type_data_di != no_parameters, "no args type data");
2441     return _parameters_type_data_di;
2442   }
2443 
2444   // Support for code generation
2445   static ByteSize data_offset() {
2446     return byte_offset_of(MethodData, _data[0]);
2447   }
2448 
2449   static ByteSize invocation_counter_offset() {
2450     return byte_offset_of(MethodData, _invocation_counter);
2451   }
2452 
2453   static ByteSize backedge_counter_offset() {
2454     return byte_offset_of(MethodData, _backedge_counter);
2455   }
2456 
2457   static ByteSize invoke_mask_offset() {
2458     return byte_offset_of(MethodData, _invoke_mask);
2459   }
2460 
2461   static ByteSize backedge_mask_offset() {
2462     return byte_offset_of(MethodData, _backedge_mask);
2463   }
2464 
2465   static ByteSize parameters_type_data_di_offset() {
2466     return byte_offset_of(MethodData, _parameters_type_data_di);
2467   }
2468 
2469   // Deallocation support - no pointer fields to deallocate
2470   void deallocate_contents(ClassLoaderData* loader_data) {}
2471 
2472   // GC support
2473   void set_size(int object_size_in_bytes) { _size = object_size_in_bytes; }
2474 
2475   // Printing
2476   void print_on      (outputStream* st) const;
2477   void print_value_on(outputStream* st) const;
2478 
2479   // printing support for method data
2480   void print_data_on(outputStream* st) const;
2481 
2482   const char* internal_name() const { return "{method data}"; }
2483 
2484   // verification
2485   void verify_on(outputStream* st);
2486   void verify_data_on(outputStream* st);
2487 
2488   static bool profile_parameters_for_method(methodHandle m);
2489   static bool profile_arguments();
2490   static bool profile_arguments_jsr292_only();
2491   static bool profile_return();
2492   static bool profile_parameters();
2493   static bool profile_return_jsr292_only();
2494 
2495   void clean_method_data(BoolObjectClosure* is_alive);
2496   void clean_weak_method_links();
2497   DEBUG_ONLY(void verify_clean_weak_method_links();)
2498   Mutex* extra_data_lock() { return &_extra_data_lock; }
2499 };
2500 
2501 #endif // SHARE_VM_OOPS_METHODDATAOOP_HPP