jdk8-mips64-public/hotspot: src/share/vm/oops/methodData.hpp@b8413a9cbb84 (annotated)

src/share/vm/oops/methodData.hpp@b8413a9cbb84 (annotated)

src/share/vm/oops/methodData.hpp

Tue, 25 Feb 2014 18:16:24 +0100

author: roland
date: Tue, 25 Feb 2014 18:16:24 +0100
changeset 6377: b8413a9cbb84
parent 6105: 6e1826d5c23e
child 6382: 1a43981d86ea
permissions: -rw-r--r--

8031752: Failed speculative optimizations should be reattempted when root of compilation is different
Summary: support for speculative traps that keep track of the root of the compilation in which a trap occurs.
Reviewed-by: kvn, twisti

 /*
  * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_OOPS_METHODDATAOOP_HPP
 #define SHARE_VM_OOPS_METHODDATAOOP_HPP
 #include "interpreter/bytecodes.hpp"
 #include "memory/universe.hpp"
 #include "oops/method.hpp"
 #include "oops/oop.hpp"
 #include "runtime/orderAccess.hpp"
 class BytecodeStream;
 class KlassSizeStats;
 // The MethodData object collects counts and other profile information
 // during zeroth-tier (interpretive) and first-tier execution.
 // The profile is used later by compilation heuristics.  Some heuristics
 // enable use of aggressive (or "heroic") optimizations.  An aggressive
 // optimization often has a down-side, a corner case that it handles
 // poorly, but which is thought to be rare.  The profile provides
 // evidence of this rarity for a given method or even BCI.  It allows
 // the compiler to back out of the optimization at places where it
 // has historically been a poor choice.  Other heuristics try to use
 // specific information gathered about types observed at a given site.
 //
 // All data in the profile is approximate.  It is expected to be accurate
 // on the whole, but the system expects occasional inaccuraces, due to
 // counter overflow, multiprocessor races during data collection, space
 // limitations, missing MDO blocks, etc.  Bad or missing data will degrade
 // optimization quality but will not affect correctness.  Also, each MDO
 // is marked with its birth-date ("creation_mileage") which can be used
 // to assess the quality ("maturity") of its data.
 //
 // Short (<32-bit) counters are designed to overflow to a known "saturated"
 // state.  Also, certain recorded per-BCI events are given one-bit counters
 // which overflow to a saturated state which applied to all counters at
 // that BCI.  In other words, there is a small lattice which approximates
 // the ideal of an infinite-precision counter for each event at each BCI,
 // and the lattice quickly "bottoms out" in a state where all counters
 // are taken to be indefinitely large.
 //
 // The reader will find many data races in profile gathering code, starting
 // with invocation counter incrementation.  None of these races harm correct
 // execution of the compiled code.
 // forward decl
 class ProfileData;
 // DataLayout
 //
 // Overlay for generic profiling data.
 class DataLayout VALUE_OBJ_CLASS_SPEC {
   friend class VMStructs;
 private:
   // Every data layout begins with a header.  This header
   // contains a tag, which is used to indicate the size/layout
   // of the data, 4 bits of flags, which can be used in any way,
   // 4 bits of trap history (none/one reason/many reasons),
   // and a bci, which is used to tie this piece of data to a
   // specific bci in the bytecodes.
   union {
     intptr_t _bits;
     struct {
       u1 _tag;
       u1 _flags;
       u2 _bci;
     } _struct;
   } _header;
   // The data layout has an arbitrary number of cells, each sized
   // to accomodate a pointer or an integer.
   intptr_t _cells[1];
   // Some types of data layouts need a length field.
   static bool needs_array_len(u1 tag);
 public:
   enum {
     counter_increment = 1
   };
   enum {
     cell_size = sizeof(intptr_t)
   };
   // Tag values
   enum {
     no_tag,
     bit_data_tag,
     counter_data_tag,
     jump_data_tag,
     receiver_type_data_tag,
     virtual_call_data_tag,
     ret_data_tag,
     branch_data_tag,
     multi_branch_data_tag,
     arg_info_data_tag,
     call_type_data_tag,
     virtual_call_type_data_tag,
     parameters_type_data_tag,
     speculative_trap_data_tag
   };
   enum {
     // The _struct._flags word is formatted as [trap_state:4 | flags:4].
     // The trap state breaks down further as [recompile:1 | reason:3].
     // This further breakdown is defined in deoptimization.cpp.
     // See Deoptimization::trap_state_reason for an assert that
     // trap_bits is big enough to hold reasons < Reason_RECORDED_LIMIT.
     //
     // The trap_state is collected only if ProfileTraps is true.
     trap_bits = 1+3,  // 3: enough to distinguish [0..Reason_RECORDED_LIMIT].
     trap_shift = BitsPerByte - trap_bits,
     trap_mask = right_n_bits(trap_bits),
     trap_mask_in_place = (trap_mask << trap_shift),
     flag_limit = trap_shift,
     flag_mask = right_n_bits(flag_limit),
     first_flag = 0
   };
   // Size computation
   static int header_size_in_bytes() {
     return cell_size;
   }
   static int header_size_in_cells() {
     return 1;
   }
   static int compute_size_in_bytes(int cell_count) {
     return header_size_in_bytes() + cell_count * cell_size;
   }
   // Initialization
   void initialize(u1 tag, u2 bci, int cell_count);
   // Accessors
   u1 tag() {
     return _header._struct._tag;
   }
   // Return a few bits of trap state.  Range is [0..trap_mask].
   // The state tells if traps with zero, one, or many reasons have occurred.
   // It also tells whether zero or many recompilations have occurred.
   // The associated trap histogram in the MDO itself tells whether
   // traps are common or not.  If a BCI shows that a trap X has
   // occurred, and the MDO shows N occurrences of X, we make the
   // simplifying assumption that all N occurrences can be blamed
   // on that BCI.
   int trap_state() const {
     return ((_header._struct._flags >> trap_shift) & trap_mask);
   }
   void set_trap_state(int new_state) {
     assert(ProfileTraps, "used only under +ProfileTraps");
     uint old_flags = (_header._struct._flags & flag_mask);
     _header._struct._flags = (new_state << trap_shift) | old_flags;
   }
   u1 flags() const {
     return _header._struct._flags;
   }
   u2 bci() const {
     return _header._struct._bci;
   }
   void set_header(intptr_t value) {
     _header._bits = value;
   }
   bool atomic_set_header(intptr_t value) {
     if (Atomic::cmpxchg_ptr(value, (volatile intptr_t*)&_header._bits, 0) == 0) {
       return true;
     }
     return false;
   }
   intptr_t header() {
     return _header._bits;
   }
   void set_cell_at(int index, intptr_t value) {
     _cells[index] = value;
   }
   void release_set_cell_at(int index, intptr_t value) {
     OrderAccess::release_store_ptr(&_cells[index], value);
   }
   intptr_t cell_at(int index) const {
     return _cells[index];
   }
   void set_flag_at(int flag_number) {
     assert(flag_number < flag_limit, "oob");
     _header._struct._flags |= (0x1 << flag_number);
   }
   bool flag_at(int flag_number) const {
     assert(flag_number < flag_limit, "oob");
     return (_header._struct._flags & (0x1 << flag_number)) != 0;
   }
   // Low-level support for code generation.
   static ByteSize header_offset() {
     return byte_offset_of(DataLayout, _header);
   }
   static ByteSize tag_offset() {
     return byte_offset_of(DataLayout, _header._struct._tag);
   }
   static ByteSize flags_offset() {
     return byte_offset_of(DataLayout, _header._struct._flags);
   }
   static ByteSize bci_offset() {
     return byte_offset_of(DataLayout, _header._struct._bci);
   }
   static ByteSize cell_offset(int index) {
     return byte_offset_of(DataLayout, _cells) + in_ByteSize(index * cell_size);
   }
   // Return a value which, when or-ed as a byte into _flags, sets the flag.
   static int flag_number_to_byte_constant(int flag_number) {
     assert(0 <= flag_number && flag_number < flag_limit, "oob");
     DataLayout temp; temp.set_header(0);
     temp.set_flag_at(flag_number);
     return temp._header._struct._flags;
   }
   // Return a value which, when or-ed as a word into _header, sets the flag.
   static intptr_t flag_mask_to_header_mask(int byte_constant) {
     DataLayout temp; temp.set_header(0);
     temp._header._struct._flags = byte_constant;
     return temp._header._bits;
   }
   ProfileData* data_in();
   // GC support
   void clean_weak_klass_links(BoolObjectClosure* cl);
 };
 // ProfileData class hierarchy
 class ProfileData;
 class   BitData;
 class     CounterData;
 class       ReceiverTypeData;
 class         VirtualCallData;
 class           VirtualCallTypeData;
 class       RetData;
 class       CallTypeData;
 class   JumpData;
 class     BranchData;
 class   ArrayData;
 class     MultiBranchData;
 class     ArgInfoData;
 class     ParametersTypeData;
 class   SpeculativeTrapData;
 // ProfileData
 //
 // A ProfileData object is created to refer to a section of profiling
 // data in a structured way.
 class ProfileData : public ResourceObj {
   friend class TypeEntries;
   friend class ReturnTypeEntry;
   friend class TypeStackSlotEntries;
 private:
 #ifndef PRODUCT
   enum {
     tab_width_one = 16,
     tab_width_two = 36
   };
 #endif // !PRODUCT
   // This is a pointer to a section of profiling data.
   DataLayout* _data;
   char* print_data_on_helper(const MethodData* md) const;
 protected:
   DataLayout* data() { return _data; }
   const DataLayout* data() const { return _data; }
   enum {
     cell_size = DataLayout::cell_size
   };
 public:
   // How many cells are in this?
   virtual int cell_count() const {
     ShouldNotReachHere();
     return -1;
   }
   // Return the size of this data.
   int size_in_bytes() {
     return DataLayout::compute_size_in_bytes(cell_count());
   }
 protected:
   // Low-level accessors for underlying data
   void set_intptr_at(int index, intptr_t value) {
     assert(0 <= index && index < cell_count(), "oob");
     data()->set_cell_at(index, value);
   }
   void release_set_intptr_at(int index, intptr_t value) {
     assert(0 <= index && index < cell_count(), "oob");
     data()->release_set_cell_at(index, value);
   }
   intptr_t intptr_at(int index) const {
     assert(0 <= index && index < cell_count(), "oob");
     return data()->cell_at(index);
   }
   void set_uint_at(int index, uint value) {
     set_intptr_at(index, (intptr_t) value);
   }
   void release_set_uint_at(int index, uint value) {
     release_set_intptr_at(index, (intptr_t) value);
   }
   uint uint_at(int index) const {
     return (uint)intptr_at(index);
   }
   void set_int_at(int index, int value) {
     set_intptr_at(index, (intptr_t) value);
   }
   void release_set_int_at(int index, int value) {
     release_set_intptr_at(index, (intptr_t) value);
   }
   int int_at(int index) const {
     return (int)intptr_at(index);
   }
   int int_at_unchecked(int index) const {
     return (int)data()->cell_at(index);
   }
   void set_oop_at(int index, oop value) {
     set_intptr_at(index, cast_from_oop<intptr_t>(value));
   }
   oop oop_at(int index) const {
     return cast_to_oop(intptr_at(index));
   }
   void set_flag_at(int flag_number) {
     data()->set_flag_at(flag_number);
   }
   bool flag_at(int flag_number) const {
     return data()->flag_at(flag_number);
   }
   // two convenient imports for use by subclasses:
   static ByteSize cell_offset(int index) {
     return DataLayout::cell_offset(index);
   }
   static int flag_number_to_byte_constant(int flag_number) {
     return DataLayout::flag_number_to_byte_constant(flag_number);
   }
   ProfileData(DataLayout* data) {
     _data = data;
   }
 public:
   // Constructor for invalid ProfileData.
   ProfileData();
   u2 bci() const {
     return data()->bci();
   }
   address dp() {
     return (address)_data;
   }
   int trap_state() const {
     return data()->trap_state();
   }
   void set_trap_state(int new_state) {
     data()->set_trap_state(new_state);
   }
   // Type checking
   virtual bool is_BitData()         const { return false; }
   virtual bool is_CounterData()     const { return false; }
   virtual bool is_JumpData()        const { return false; }
   virtual bool is_ReceiverTypeData()const { return false; }
   virtual bool is_VirtualCallData() const { return false; }
   virtual bool is_RetData()         const { return false; }
   virtual bool is_BranchData()      const { return false; }
   virtual bool is_ArrayData()       const { return false; }
   virtual bool is_MultiBranchData() const { return false; }
   virtual bool is_ArgInfoData()     const { return false; }
   virtual bool is_CallTypeData()    const { return false; }
   virtual bool is_VirtualCallTypeData()const { return false; }
   virtual bool is_ParametersTypeData() const { return false; }
   virtual bool is_SpeculativeTrapData()const { return false; }
   BitData* as_BitData() const {
     assert(is_BitData(), "wrong type");
     return is_BitData()         ? (BitData*)        this : NULL;
   }
   CounterData* as_CounterData() const {
     assert(is_CounterData(), "wrong type");
     return is_CounterData()     ? (CounterData*)    this : NULL;
   }
   JumpData* as_JumpData() const {
     assert(is_JumpData(), "wrong type");
     return is_JumpData()        ? (JumpData*)       this : NULL;
   }
   ReceiverTypeData* as_ReceiverTypeData() const {
     assert(is_ReceiverTypeData(), "wrong type");
     return is_ReceiverTypeData() ? (ReceiverTypeData*)this : NULL;
   }
   VirtualCallData* as_VirtualCallData() const {
     assert(is_VirtualCallData(), "wrong type");
     return is_VirtualCallData() ? (VirtualCallData*)this : NULL;
   }
   RetData* as_RetData() const {
     assert(is_RetData(), "wrong type");
     return is_RetData()         ? (RetData*)        this : NULL;
   }
   BranchData* as_BranchData() const {
     assert(is_BranchData(), "wrong type");
     return is_BranchData()      ? (BranchData*)     this : NULL;
   }
   ArrayData* as_ArrayData() const {
     assert(is_ArrayData(), "wrong type");
     return is_ArrayData()       ? (ArrayData*)      this : NULL;
   }
   MultiBranchData* as_MultiBranchData() const {
     assert(is_MultiBranchData(), "wrong type");
     return is_MultiBranchData() ? (MultiBranchData*)this : NULL;
   }
   ArgInfoData* as_ArgInfoData() const {
     assert(is_ArgInfoData(), "wrong type");
     return is_ArgInfoData() ? (ArgInfoData*)this : NULL;
   }
   CallTypeData* as_CallTypeData() const {
     assert(is_CallTypeData(), "wrong type");
     return is_CallTypeData() ? (CallTypeData*)this : NULL;
   }
   VirtualCallTypeData* as_VirtualCallTypeData() const {
     assert(is_VirtualCallTypeData(), "wrong type");
     return is_VirtualCallTypeData() ? (VirtualCallTypeData*)this : NULL;
   }
   ParametersTypeData* as_ParametersTypeData() const {
     assert(is_ParametersTypeData(), "wrong type");
     return is_ParametersTypeData() ? (ParametersTypeData*)this : NULL;
   }
   SpeculativeTrapData* as_SpeculativeTrapData() const {
     assert(is_SpeculativeTrapData(), "wrong type");
     return is_SpeculativeTrapData() ? (SpeculativeTrapData*)this : NULL;
   }
   // Subclass specific initialization
   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo) {}
   // GC support
   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {}
   // CI translation: ProfileData can represent both MethodDataOop data
   // as well as CIMethodData data. This function is provided for translating
   // an oop in a ProfileData to the ci equivalent. Generally speaking,
   // most ProfileData don't require any translation, so we provide the null
   // translation here, and the required translators are in the ci subclasses.
   virtual void translate_from(const ProfileData* data) {}
   virtual void print_data_on(outputStream* st, const char* extra = NULL) const {
     ShouldNotReachHere();
   }
   void print_data_on(outputStream* st, const MethodData* md) const;
 #ifndef PRODUCT
   void print_shared(outputStream* st, const char* name, const char* extra) const;
   void tab(outputStream* st, bool first = false) const;
 #endif
 };
 // BitData
 //
 // A BitData holds a flag or two in its header.
 class BitData : public ProfileData {
 protected:
   enum {
     // null_seen:
     //  saw a null operand (cast/aastore/instanceof)
     null_seen_flag              = DataLayout::first_flag + 0
   };
   enum { bit_cell_count = 0 };  // no additional data fields needed.
 public:
   BitData(DataLayout* layout) : ProfileData(layout) {
   }
   virtual bool is_BitData() const { return true; }
   static int static_cell_count() {
     return bit_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Accessor
   // The null_seen flag bit is specially known to the interpreter.
   // Consulting it allows the compiler to avoid setting up null_check traps.
   bool null_seen()     { return flag_at(null_seen_flag); }
   void set_null_seen()    { set_flag_at(null_seen_flag); }
   // Code generation support
   static int null_seen_byte_constant() {
     return flag_number_to_byte_constant(null_seen_flag);
   }
   static ByteSize bit_data_size() {
     return cell_offset(bit_cell_count);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // CounterData
 //
 // A CounterData corresponds to a simple counter.
 class CounterData : public BitData {
 protected:
   enum {
     count_off,
     counter_cell_count
   };
 public:
   CounterData(DataLayout* layout) : BitData(layout) {}
   virtual bool is_CounterData() const { return true; }
   static int static_cell_count() {
     return counter_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessor
   uint count() const {
     return uint_at(count_off);
   }
   // Code generation support
   static ByteSize count_offset() {
     return cell_offset(count_off);
   }
   static ByteSize counter_data_size() {
     return cell_offset(counter_cell_count);
   }
   void set_count(uint count) {
     set_uint_at(count_off, count);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // JumpData
 //
 // A JumpData is used to access profiling information for a direct
 // branch.  It is a counter, used for counting the number of branches,
 // plus a data displacement, used for realigning the data pointer to
 // the corresponding target bci.
 class JumpData : public ProfileData {
 protected:
   enum {
     taken_off_set,
     displacement_off_set,
     jump_cell_count
   };
   void set_displacement(int displacement) {
     set_int_at(displacement_off_set, displacement);
   }
 public:
   JumpData(DataLayout* layout) : ProfileData(layout) {
     assert(layout->tag() == DataLayout::jump_data_tag ||
       layout->tag() == DataLayout::branch_data_tag, "wrong type");
   }
   virtual bool is_JumpData() const { return true; }
   static int static_cell_count() {
     return jump_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessor
   uint taken() const {
     return uint_at(taken_off_set);
   }
   void set_taken(uint cnt) {
     set_uint_at(taken_off_set, cnt);
   }
   // Saturating counter
   uint inc_taken() {
     uint cnt = taken() + 1;
     // Did we wrap? Will compiler screw us??
     if (cnt == 0) cnt--;
     set_uint_at(taken_off_set, cnt);
     return cnt;
   }
   int displacement() const {
     return int_at(displacement_off_set);
   }
   // Code generation support
   static ByteSize taken_offset() {
     return cell_offset(taken_off_set);
   }
   static ByteSize displacement_offset() {
     return cell_offset(displacement_off_set);
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // Entries in a ProfileData object to record types: it can either be
 // none (no profile), unknown (conflicting profile data) or a klass if
 // a single one is seen. Whether a null reference was seen is also
 // recorded. No counter is associated with the type and a single type
 // is tracked (unlike VirtualCallData).
 class TypeEntries {
 public:
   // A single cell is used to record information for a type:
   // - the cell is initialized to 0
   // - when a type is discovered it is stored in the cell
   // - bit zero of the cell is used to record whether a null reference
   // was encountered or not
   // - bit 1 is set to record a conflict in the type information
   enum {
     null_seen = 1,
     type_mask = ~null_seen,
     type_unknown = 2,
     status_bits = null_seen | type_unknown,
     type_klass_mask = ~status_bits
   };
   // what to initialize a cell to
   static intptr_t type_none() {
     return 0;
   }
   // null seen = bit 0 set?
   static bool was_null_seen(intptr_t v) {
     return (v & null_seen) != 0;
   }
   // conflicting type information = bit 1 set?
   static bool is_type_unknown(intptr_t v) {
     return (v & type_unknown) != 0;
   }
   // not type information yet = all bits cleared, ignoring bit 0?
   static bool is_type_none(intptr_t v) {
     return (v & type_mask) == 0;
   }
   // recorded type: cell without bit 0 and 1
   static intptr_t klass_part(intptr_t v) {
     intptr_t r = v & type_klass_mask;
     return r;
   }
   // type recorded
   static Klass* valid_klass(intptr_t k) {
     if (!is_type_none(k) &&
         !is_type_unknown(k)) {
       Klass* res = (Klass*)klass_part(k);
       assert(res != NULL, "invalid");
       return res;
     } else {
       return NULL;
     }
   }
   static intptr_t with_status(intptr_t k, intptr_t in) {
     return k | (in & status_bits);
   }
   static intptr_t with_status(Klass* k, intptr_t in) {
     return with_status((intptr_t)k, in);
   }
 #ifndef PRODUCT
   static void print_klass(outputStream* st, intptr_t k);
 #endif
   // GC support
   static bool is_loader_alive(BoolObjectClosure* is_alive_cl, intptr_t p);
 protected:
   // ProfileData object these entries are part of
   ProfileData* _pd;
   // offset within the ProfileData object where the entries start
   const int _base_off;
   TypeEntries(int base_off)
     : _base_off(base_off), _pd(NULL) {}
   void set_intptr_at(int index, intptr_t value) {
     _pd->set_intptr_at(index, value);
   }
   intptr_t intptr_at(int index) const {
     return _pd->intptr_at(index);
   }
 public:
   void set_profile_data(ProfileData* pd) {
     _pd = pd;
   }
 };
 // Type entries used for arguments passed at a call and parameters on
 // method entry. 2 cells per entry: one for the type encoded as in
 // TypeEntries and one initialized with the stack slot where the
 // profiled object is to be found so that the interpreter can locate
 // it quickly.
 class TypeStackSlotEntries : public TypeEntries {
 private:
   enum {
     stack_slot_entry,
     type_entry,
     per_arg_cell_count
   };
   // offset of cell for stack slot for entry i within ProfileData object
   int stack_slot_offset(int i) const {
     return _base_off + stack_slot_local_offset(i);
   }
 protected:
   const int _number_of_entries;
   // offset of cell for type for entry i within ProfileData object
   int type_offset(int i) const {
     return _base_off + type_local_offset(i);
   }
 public:
   TypeStackSlotEntries(int base_off, int nb_entries)
     : TypeEntries(base_off), _number_of_entries(nb_entries) {}
   static int compute_cell_count(Symbol* signature, bool include_receiver, int max);
   void post_initialize(Symbol* signature, bool has_receiver, bool include_receiver);
   // offset of cell for stack slot for entry i within this block of cells for a TypeStackSlotEntries
   static int stack_slot_local_offset(int i) {
     return i * per_arg_cell_count + stack_slot_entry;
   }
   // offset of cell for type for entry i within this block of cells for a TypeStackSlotEntries
   static int type_local_offset(int i) {
     return i * per_arg_cell_count + type_entry;
   }
   // stack slot for entry i
   uint stack_slot(int i) const {
     assert(i >= 0 && i < _number_of_entries, "oob");
     return _pd->uint_at(stack_slot_offset(i));
   }
   // set stack slot for entry i
   void set_stack_slot(int i, uint num) {
     assert(i >= 0 && i < _number_of_entries, "oob");
     _pd->set_uint_at(stack_slot_offset(i), num);
   }
   // type for entry i
   intptr_t type(int i) const {
     assert(i >= 0 && i < _number_of_entries, "oob");
     return _pd->intptr_at(type_offset(i));
   }
   // set type for entry i
   void set_type(int i, intptr_t k) {
     assert(i >= 0 && i < _number_of_entries, "oob");
     _pd->set_intptr_at(type_offset(i), k);
   }
   static ByteSize per_arg_size() {
     return in_ByteSize(per_arg_cell_count * DataLayout::cell_size);
   }
   static int per_arg_count() {
     return per_arg_cell_count ;
   }
   // GC support
   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 #ifndef PRODUCT
   void print_data_on(outputStream* st) const;
 #endif
 };
 // Type entry used for return from a call. A single cell to record the
 // type.
 class ReturnTypeEntry : public TypeEntries {
 private:
   enum {
     cell_count = 1
   };
 public:
   ReturnTypeEntry(int base_off)
     : TypeEntries(base_off) {}
   void post_initialize() {
     set_type(type_none());
   }
   intptr_t type() const {
     return _pd->intptr_at(_base_off);
   }
   void set_type(intptr_t k) {
     _pd->set_intptr_at(_base_off, k);
   }
   static int static_cell_count() {
     return cell_count;
   }
   static ByteSize size() {
     return in_ByteSize(cell_count * DataLayout::cell_size);
   }
   ByteSize type_offset() {
     return DataLayout::cell_offset(_base_off);
   }
   // GC support
   void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 #ifndef PRODUCT
   void print_data_on(outputStream* st) const;
 #endif
 };
 // Entries to collect type information at a call: contains arguments
 // (TypeStackSlotEntries), a return type (ReturnTypeEntry) and a
 // number of cells. Because the number of cells for the return type is
 // smaller than the number of cells for the type of an arguments, the
 // number of cells is used to tell how many arguments are profiled and
 // whether a return value is profiled. See has_arguments() and
 // has_return().
 class TypeEntriesAtCall {
 private:
   static int stack_slot_local_offset(int i) {
     return header_cell_count() + TypeStackSlotEntries::stack_slot_local_offset(i);
   }
   static int argument_type_local_offset(int i) {
     return header_cell_count() + TypeStackSlotEntries::type_local_offset(i);;
   }
 public:
   static int header_cell_count() {
     return 1;
   }
   static int cell_count_local_offset() {
     return 0;
   }
   static int compute_cell_count(BytecodeStream* stream);
   static void initialize(DataLayout* dl, int base, int cell_count) {
     int off = base + cell_count_local_offset();
     dl->set_cell_at(off, cell_count - base - header_cell_count());
   }
   static bool arguments_profiling_enabled();
   static bool return_profiling_enabled();
   // Code generation support
   static ByteSize cell_count_offset() {
     return in_ByteSize(cell_count_local_offset() * DataLayout::cell_size);
   }
   static ByteSize args_data_offset() {
     return in_ByteSize(header_cell_count() * DataLayout::cell_size);
   }
   static ByteSize stack_slot_offset(int i) {
     return in_ByteSize(stack_slot_local_offset(i) * DataLayout::cell_size);
   }
   static ByteSize argument_type_offset(int i) {
     return in_ByteSize(argument_type_local_offset(i) * DataLayout::cell_size);
   }
 };
 // CallTypeData
 //
 // A CallTypeData is used to access profiling information about a non
 // virtual call for which we collect type information about arguments
 // and return value.
 class CallTypeData : public CounterData {
 private:
   // entries for arguments if any
   TypeStackSlotEntries _args;
   // entry for return type if any
   ReturnTypeEntry _ret;
   int cell_count_global_offset() const {
     return CounterData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
   }
   // number of cells not counting the header
   int cell_count_no_header() const {
     return uint_at(cell_count_global_offset());
   }
   void check_number_of_arguments(int total) {
     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
   }
 public:
   CallTypeData(DataLayout* layout) :
     CounterData(layout),
     _args(CounterData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
   {
     assert(layout->tag() == DataLayout::call_type_data_tag, "wrong type");
     // Some compilers (VC++) don't want this passed in member initialization list
     _args.set_profile_data(this);
     _ret.set_profile_data(this);
   }
   const TypeStackSlotEntries* args() const {
     assert(has_arguments(), "no profiling of arguments");
     return &_args;
   }
   const ReturnTypeEntry* ret() const {
     assert(has_return(), "no profiling of return value");
     return &_ret;
   }
   virtual bool is_CallTypeData() const { return true; }
   static int static_cell_count() {
     return -1;
   }
   static int compute_cell_count(BytecodeStream* stream) {
     return CounterData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
   }
   static void initialize(DataLayout* dl, int cell_count) {
     TypeEntriesAtCall::initialize(dl, CounterData::static_cell_count(), cell_count);
   }
   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
   virtual int cell_count() const {
     return CounterData::static_cell_count() +
       TypeEntriesAtCall::header_cell_count() +
       int_at_unchecked(cell_count_global_offset());
   }
   int number_of_arguments() const {
     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
   }
   void set_argument_type(int i, Klass* k) {
     assert(has_arguments(), "no arguments!");
     intptr_t current = _args.type(i);
     _args.set_type(i, TypeEntries::with_status(k, current));
   }
   void set_return_type(Klass* k) {
     assert(has_return(), "no return!");
     intptr_t current = _ret.type();
     _ret.set_type(TypeEntries::with_status(k, current));
   }
   // An entry for a return value takes less space than an entry for an
   // argument so if the number of cells exceeds the number of cells
   // needed for an argument, this object contains type information for
   // at least one argument.
   bool has_arguments() const {
     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
     return res;
   }
   // An entry for a return value takes less space than an entry for an
   // argument, so if the remainder of the number of cells divided by
   // the number of cells for an argument is not null, a return value
   // is profiled in this object.
   bool has_return() const {
     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
     return res;
   }
   // Code generation support
   static ByteSize args_data_offset() {
     return cell_offset(CounterData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
   }
   // GC support
   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
     if (has_arguments()) {
       _args.clean_weak_klass_links(is_alive_closure);
     }
     if (has_return()) {
       _ret.clean_weak_klass_links(is_alive_closure);
     }
   }
 #ifndef PRODUCT
   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // ReceiverTypeData
 //
 // A ReceiverTypeData is used to access profiling information about a
 // dynamic type check.  It consists of a counter which counts the total times
 // that the check is reached, and a series of (Klass*, count) pairs
 // which are used to store a type profile for the receiver of the check.
 class ReceiverTypeData : public CounterData {
 protected:
   enum {
     receiver0_offset = counter_cell_count,
     count0_offset,
     receiver_type_row_cell_count = (count0_offset + 1) - receiver0_offset
   };
 public:
   ReceiverTypeData(DataLayout* layout) : CounterData(layout) {
     assert(layout->tag() == DataLayout::receiver_type_data_tag ||
            layout->tag() == DataLayout::virtual_call_data_tag ||
            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
   }
   virtual bool is_ReceiverTypeData() const { return true; }
   static int static_cell_count() {
     return counter_cell_count + (uint) TypeProfileWidth * receiver_type_row_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessors
   static uint row_limit() {
     return TypeProfileWidth;
   }
   static int receiver_cell_index(uint row) {
     return receiver0_offset + row * receiver_type_row_cell_count;
   }
   static int receiver_count_cell_index(uint row) {
     return count0_offset + row * receiver_type_row_cell_count;
   }
   Klass* receiver(uint row) const {
     assert(row < row_limit(), "oob");
     Klass* recv = (Klass*)intptr_at(receiver_cell_index(row));
     assert(recv == NULL || recv->is_klass(), "wrong type");
     return recv;
   }
   void set_receiver(uint row, Klass* k) {
     assert((uint)row < row_limit(), "oob");
     set_intptr_at(receiver_cell_index(row), (uintptr_t)k);
   }
   uint receiver_count(uint row) const {
     assert(row < row_limit(), "oob");
     return uint_at(receiver_count_cell_index(row));
   }
   void set_receiver_count(uint row, uint count) {
     assert(row < row_limit(), "oob");
     set_uint_at(receiver_count_cell_index(row), count);
   }
   void clear_row(uint row) {
     assert(row < row_limit(), "oob");
     // Clear total count - indicator of polymorphic call site.
     // The site may look like as monomorphic after that but
     // it allow to have more accurate profiling information because
     // there was execution phase change since klasses were unloaded.
     // If the site is still polymorphic then MDO will be updated
     // to reflect it. But it could be the case that the site becomes
     // only bimorphic. Then keeping total count not 0 will be wrong.
     // Even if we use monomorphic (when it is not) for compilation
     // we will only have trap, deoptimization and recompile again
     // with updated MDO after executing method in Interpreter.
     // An additional receiver will be recorded in the cleaned row
     // during next call execution.
     //
     // Note: our profiling logic works with empty rows in any slot.
     // We do sorting a profiling info (ciCallProfile) for compilation.
     //
     set_count(0);
     set_receiver(row, NULL);
     set_receiver_count(row, 0);
   }
   // Code generation support
   static ByteSize receiver_offset(uint row) {
     return cell_offset(receiver_cell_index(row));
   }
   static ByteSize receiver_count_offset(uint row) {
     return cell_offset(receiver_count_cell_index(row));
   }
   static ByteSize receiver_type_data_size() {
     return cell_offset(static_cell_count());
   }
   // GC support
   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure);
 #ifndef PRODUCT
   void print_receiver_data_on(outputStream* st) const;
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // VirtualCallData
 //
 // A VirtualCallData is used to access profiling information about a
 // virtual call.  For now, it has nothing more than a ReceiverTypeData.
 class VirtualCallData : public ReceiverTypeData {
 public:
   VirtualCallData(DataLayout* layout) : ReceiverTypeData(layout) {
     assert(layout->tag() == DataLayout::virtual_call_data_tag ||
            layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
   }
   virtual bool is_VirtualCallData() const { return true; }
   static int static_cell_count() {
     // At this point we could add more profile state, e.g., for arguments.
     // But for now it's the same size as the base record type.
     return ReceiverTypeData::static_cell_count();
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessors
   static ByteSize virtual_call_data_size() {
     return cell_offset(static_cell_count());
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // VirtualCallTypeData
 //
 // A VirtualCallTypeData is used to access profiling information about
 // a virtual call for which we collect type information about
 // arguments and return value.
 class VirtualCallTypeData : public VirtualCallData {
 private:
   // entries for arguments if any
   TypeStackSlotEntries _args;
   // entry for return type if any
   ReturnTypeEntry _ret;
   int cell_count_global_offset() const {
     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::cell_count_local_offset();
   }
   // number of cells not counting the header
   int cell_count_no_header() const {
     return uint_at(cell_count_global_offset());
   }
   void check_number_of_arguments(int total) {
     assert(number_of_arguments() == total, "should be set in DataLayout::initialize");
   }
 public:
   VirtualCallTypeData(DataLayout* layout) :
     VirtualCallData(layout),
     _args(VirtualCallData::static_cell_count()+TypeEntriesAtCall::header_cell_count(), number_of_arguments()),
     _ret(cell_count() - ReturnTypeEntry::static_cell_count())
   {
     assert(layout->tag() == DataLayout::virtual_call_type_data_tag, "wrong type");
     // Some compilers (VC++) don't want this passed in member initialization list
     _args.set_profile_data(this);
     _ret.set_profile_data(this);
   }
   const TypeStackSlotEntries* args() const {
     assert(has_arguments(), "no profiling of arguments");
     return &_args;
   }
   const ReturnTypeEntry* ret() const {
     assert(has_return(), "no profiling of return value");
     return &_ret;
   }
   virtual bool is_VirtualCallTypeData() const { return true; }
   static int static_cell_count() {
     return -1;
   }
   static int compute_cell_count(BytecodeStream* stream) {
     return VirtualCallData::static_cell_count() + TypeEntriesAtCall::compute_cell_count(stream);
   }
   static void initialize(DataLayout* dl, int cell_count) {
     TypeEntriesAtCall::initialize(dl, VirtualCallData::static_cell_count(), cell_count);
   }
   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
   virtual int cell_count() const {
     return VirtualCallData::static_cell_count() +
       TypeEntriesAtCall::header_cell_count() +
       int_at_unchecked(cell_count_global_offset());
   }
   int number_of_arguments() const {
     return cell_count_no_header() / TypeStackSlotEntries::per_arg_count();
   }
   void set_argument_type(int i, Klass* k) {
     assert(has_arguments(), "no arguments!");
     intptr_t current = _args.type(i);
     _args.set_type(i, TypeEntries::with_status(k, current));
   }
   void set_return_type(Klass* k) {
     assert(has_return(), "no return!");
     intptr_t current = _ret.type();
     _ret.set_type(TypeEntries::with_status(k, current));
   }
   // An entry for a return value takes less space than an entry for an
   // argument, so if the remainder of the number of cells divided by
   // the number of cells for an argument is not null, a return value
   // is profiled in this object.
   bool has_return() const {
     bool res = (cell_count_no_header() % TypeStackSlotEntries::per_arg_count()) != 0;
     assert (!res || TypeEntriesAtCall::return_profiling_enabled(), "no profiling of return values");
     return res;
   }
   // An entry for a return value takes less space than an entry for an
   // argument so if the number of cells exceeds the number of cells
   // needed for an argument, this object contains type information for
   // at least one argument.
   bool has_arguments() const {
     bool res = cell_count_no_header() >= TypeStackSlotEntries::per_arg_count();
     assert (!res || TypeEntriesAtCall::arguments_profiling_enabled(), "no profiling of arguments");
     return res;
   }
   // Code generation support
   static ByteSize args_data_offset() {
     return cell_offset(VirtualCallData::static_cell_count()) + TypeEntriesAtCall::args_data_offset();
   }
   // GC support
   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
     ReceiverTypeData::clean_weak_klass_links(is_alive_closure);
     if (has_arguments()) {
       _args.clean_weak_klass_links(is_alive_closure);
     }
     if (has_return()) {
       _ret.clean_weak_klass_links(is_alive_closure);
     }
   }
 #ifndef PRODUCT
   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // RetData
 //
 // A RetData is used to access profiling information for a ret bytecode.
 // It is composed of a count of the number of times that the ret has
 // been executed, followed by a series of triples of the form
 // (bci, count, di) which count the number of times that some bci was the
 // target of the ret and cache a corresponding data displacement.
 class RetData : public CounterData {
 protected:
   enum {
     bci0_offset = counter_cell_count,
     count0_offset,
     displacement0_offset,
     ret_row_cell_count = (displacement0_offset + 1) - bci0_offset
   };
   void set_bci(uint row, int bci) {
     assert((uint)row < row_limit(), "oob");
     set_int_at(bci0_offset + row * ret_row_cell_count, bci);
   }
   void release_set_bci(uint row, int bci) {
     assert((uint)row < row_limit(), "oob");
     // 'release' when setting the bci acts as a valid flag for other
     // threads wrt bci_count and bci_displacement.
     release_set_int_at(bci0_offset + row * ret_row_cell_count, bci);
   }
   void set_bci_count(uint row, uint count) {
     assert((uint)row < row_limit(), "oob");
     set_uint_at(count0_offset + row * ret_row_cell_count, count);
   }
   void set_bci_displacement(uint row, int disp) {
     set_int_at(displacement0_offset + row * ret_row_cell_count, disp);
   }
 public:
   RetData(DataLayout* layout) : CounterData(layout) {
     assert(layout->tag() == DataLayout::ret_data_tag, "wrong type");
   }
   virtual bool is_RetData() const { return true; }
   enum {
     no_bci = -1 // value of bci when bci1/2 are not in use.
   };
   static int static_cell_count() {
     return counter_cell_count + (uint) BciProfileWidth * ret_row_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   static uint row_limit() {
     return BciProfileWidth;
   }
   static int bci_cell_index(uint row) {
     return bci0_offset + row * ret_row_cell_count;
   }
   static int bci_count_cell_index(uint row) {
     return count0_offset + row * ret_row_cell_count;
   }
   static int bci_displacement_cell_index(uint row) {
     return displacement0_offset + row * ret_row_cell_count;
   }
   // Direct accessors
   int bci(uint row) const {
     return int_at(bci_cell_index(row));
   }
   uint bci_count(uint row) const {
     return uint_at(bci_count_cell_index(row));
   }
   int bci_displacement(uint row) const {
     return int_at(bci_displacement_cell_index(row));
   }
   // Interpreter Runtime support
   address fixup_ret(int return_bci, MethodData* mdo);
   // Code generation support
   static ByteSize bci_offset(uint row) {
     return cell_offset(bci_cell_index(row));
   }
   static ByteSize bci_count_offset(uint row) {
     return cell_offset(bci_count_cell_index(row));
   }
   static ByteSize bci_displacement_offset(uint row) {
     return cell_offset(bci_displacement_cell_index(row));
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // BranchData
 //
 // A BranchData is used to access profiling data for a two-way branch.
 // It consists of taken and not_taken counts as well as a data displacement
 // for the taken case.
 class BranchData : public JumpData {
 protected:
   enum {
     not_taken_off_set = jump_cell_count,
     branch_cell_count
   };
   void set_displacement(int displacement) {
     set_int_at(displacement_off_set, displacement);
   }
 public:
   BranchData(DataLayout* layout) : JumpData(layout) {
     assert(layout->tag() == DataLayout::branch_data_tag, "wrong type");
   }
   virtual bool is_BranchData() const { return true; }
   static int static_cell_count() {
     return branch_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessor
   uint not_taken() const {
     return uint_at(not_taken_off_set);
   }
   void set_not_taken(uint cnt) {
     set_uint_at(not_taken_off_set, cnt);
   }
   uint inc_not_taken() {
     uint cnt = not_taken() + 1;
     // Did we wrap? Will compiler screw us??
     if (cnt == 0) cnt--;
     set_uint_at(not_taken_off_set, cnt);
     return cnt;
   }
   // Code generation support
   static ByteSize not_taken_offset() {
     return cell_offset(not_taken_off_set);
   }
   static ByteSize branch_data_size() {
     return cell_offset(branch_cell_count);
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // ArrayData
 //
 // A ArrayData is a base class for accessing profiling data which does
 // not have a statically known size.  It consists of an array length
 // and an array start.
 class ArrayData : public ProfileData {
 protected:
   friend class DataLayout;
   enum {
     array_len_off_set,
     array_start_off_set
   };
   uint array_uint_at(int index) const {
     int aindex = index + array_start_off_set;
     return uint_at(aindex);
   }
   int array_int_at(int index) const {
     int aindex = index + array_start_off_set;
     return int_at(aindex);
   }
   oop array_oop_at(int index) const {
     int aindex = index + array_start_off_set;
     return oop_at(aindex);
   }
   void array_set_int_at(int index, int value) {
     int aindex = index + array_start_off_set;
     set_int_at(aindex, value);
   }
   // Code generation support for subclasses.
   static ByteSize array_element_offset(int index) {
     return cell_offset(array_start_off_set + index);
   }
 public:
   ArrayData(DataLayout* layout) : ProfileData(layout) {}
   virtual bool is_ArrayData() const { return true; }
   static int static_cell_count() {
     return -1;
   }
   int array_len() const {
     return int_at_unchecked(array_len_off_set);
   }
   virtual int cell_count() const {
     return array_len() + 1;
   }
   // Code generation support
   static ByteSize array_len_offset() {
     return cell_offset(array_len_off_set);
   }
   static ByteSize array_start_offset() {
     return cell_offset(array_start_off_set);
   }
 };
 // MultiBranchData
 //
 // A MultiBranchData is used to access profiling information for
 // a multi-way branch (*switch bytecodes).  It consists of a series
 // of (count, displacement) pairs, which count the number of times each
 // case was taken and specify the data displacment for each branch target.
 class MultiBranchData : public ArrayData {
 protected:
   enum {
     default_count_off_set,
     default_disaplacement_off_set,
     case_array_start
   };
   enum {
     relative_count_off_set,
     relative_displacement_off_set,
     per_case_cell_count
   };
   void set_default_displacement(int displacement) {
     array_set_int_at(default_disaplacement_off_set, displacement);
   }
   void set_displacement_at(int index, int displacement) {
     array_set_int_at(case_array_start +
                      index * per_case_cell_count +
                      relative_displacement_off_set,
                      displacement);
   }
 public:
   MultiBranchData(DataLayout* layout) : ArrayData(layout) {
     assert(layout->tag() == DataLayout::multi_branch_data_tag, "wrong type");
   }
   virtual bool is_MultiBranchData() const { return true; }
   static int compute_cell_count(BytecodeStream* stream);
   int number_of_cases() const {
     int alen = array_len() - 2; // get rid of default case here.
     assert(alen % per_case_cell_count == 0, "must be even");
     return (alen / per_case_cell_count);
   }
   uint default_count() const {
     return array_uint_at(default_count_off_set);
   }
   int default_displacement() const {
     return array_int_at(default_disaplacement_off_set);
   }
   uint count_at(int index) const {
     return array_uint_at(case_array_start +
                          index * per_case_cell_count +
                          relative_count_off_set);
   }
   int displacement_at(int index) const {
     return array_int_at(case_array_start +
                         index * per_case_cell_count +
                         relative_displacement_off_set);
   }
   // Code generation support
   static ByteSize default_count_offset() {
     return array_element_offset(default_count_off_set);
   }
   static ByteSize default_displacement_offset() {
     return array_element_offset(default_disaplacement_off_set);
   }
   static ByteSize case_count_offset(int index) {
     return case_array_offset() +
            (per_case_size() * index) +
            relative_count_offset();
   }
   static ByteSize case_array_offset() {
     return array_element_offset(case_array_start);
   }
   static ByteSize per_case_size() {
     return in_ByteSize(per_case_cell_count) * cell_size;
   }
   static ByteSize relative_count_offset() {
     return in_ByteSize(relative_count_off_set) * cell_size;
   }
   static ByteSize relative_displacement_offset() {
     return in_ByteSize(relative_displacement_off_set) * cell_size;
   }
   // Specific initialization.
   void post_initialize(BytecodeStream* stream, MethodData* mdo);
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 class ArgInfoData : public ArrayData {
 public:
   ArgInfoData(DataLayout* layout) : ArrayData(layout) {
     assert(layout->tag() == DataLayout::arg_info_data_tag, "wrong type");
   }
   virtual bool is_ArgInfoData() const { return true; }
   int number_of_args() const {
     return array_len();
   }
   uint arg_modified(int arg) const {
     return array_uint_at(arg);
   }
   void set_arg_modified(int arg, uint val) {
     array_set_int_at(arg, val);
   }
 #ifndef PRODUCT
   void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // ParametersTypeData
 //
 // A ParametersTypeData is used to access profiling information about
 // types of parameters to a method
 class ParametersTypeData : public ArrayData {
 private:
   TypeStackSlotEntries _parameters;
   static int stack_slot_local_offset(int i) {
     assert_profiling_enabled();
     return array_start_off_set + TypeStackSlotEntries::stack_slot_local_offset(i);
   }
   static int type_local_offset(int i) {
     assert_profiling_enabled();
     return array_start_off_set + TypeStackSlotEntries::type_local_offset(i);
   }
   static bool profiling_enabled();
   static void assert_profiling_enabled() {
     assert(profiling_enabled(), "method parameters profiling should be on");
   }
 public:
   ParametersTypeData(DataLayout* layout) : ArrayData(layout), _parameters(1, number_of_parameters()) {
     assert(layout->tag() == DataLayout::parameters_type_data_tag, "wrong type");
     // Some compilers (VC++) don't want this passed in member initialization list
     _parameters.set_profile_data(this);
   }
   static int compute_cell_count(Method* m);
   virtual bool is_ParametersTypeData() const { return true; }
   virtual void post_initialize(BytecodeStream* stream, MethodData* mdo);
   int number_of_parameters() const {
     return array_len() / TypeStackSlotEntries::per_arg_count();
   }
   const TypeStackSlotEntries* parameters() const { return &_parameters; }
   uint stack_slot(int i) const {
     return _parameters.stack_slot(i);
   }
   void set_type(int i, Klass* k) {
     intptr_t current = _parameters.type(i);
     _parameters.set_type(i, TypeEntries::with_status((intptr_t)k, current));
   }
   virtual void clean_weak_klass_links(BoolObjectClosure* is_alive_closure) {
     _parameters.clean_weak_klass_links(is_alive_closure);
   }
 #ifndef PRODUCT
   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
   static ByteSize stack_slot_offset(int i) {
     return cell_offset(stack_slot_local_offset(i));
   }
   static ByteSize type_offset(int i) {
     return cell_offset(type_local_offset(i));
   }
 };
 // SpeculativeTrapData
 //
 // A SpeculativeTrapData is used to record traps due to type
 // speculation. It records the root of the compilation: that type
 // speculation is wrong in the context of one compilation (for
 // method1) doesn't mean it's wrong in the context of another one (for
 // method2). Type speculation could have more/different data in the
 // context of the compilation of method2 and it's worthwhile to try an
 // optimization that failed for compilation of method1 in the context
 // of compilation of method2.
 // Space for SpeculativeTrapData entries is allocated from the extra
 // data space in the MDO. If we run out of space, the trap data for
 // the ProfileData at that bci is updated.
 class SpeculativeTrapData : public ProfileData {
 protected:
   enum {
     method_offset,
     speculative_trap_cell_count
   };
 public:
   SpeculativeTrapData(DataLayout* layout) : ProfileData(layout) {
     assert(layout->tag() == DataLayout::speculative_trap_data_tag, "wrong type");
   }
   virtual bool is_SpeculativeTrapData() const { return true; }
   static int static_cell_count() {
     return speculative_trap_cell_count;
   }
   virtual int cell_count() const {
     return static_cell_count();
   }
   // Direct accessor
   Method* method() const {
     return (Method*)intptr_at(method_offset);
   }
   void set_method(Method* m) {
     set_intptr_at(method_offset, (intptr_t)m);
   }
 #ifndef PRODUCT
   virtual void print_data_on(outputStream* st, const char* extra = NULL) const;
 #endif
 };
 // MethodData*
 //
 // A MethodData* holds information which has been collected about
 // a method.  Its layout looks like this:
 //
 // -----------------------------
 // | header                    |
 // | klass                     |
 // -----------------------------
 // | method                    |
 // | size of the MethodData* |
 // -----------------------------
 // | Data entries...           |
 // |   (variable size)         |
 // |                           |
 // .                           .
 // .                           .
 // .                           .
 // |                           |
 // -----------------------------
 //
 // The data entry area is a heterogeneous array of DataLayouts. Each
 // DataLayout in the array corresponds to a specific bytecode in the
 // method.  The entries in the array are sorted by the corresponding
 // bytecode.  Access to the data is via resource-allocated ProfileData,
 // which point to the underlying blocks of DataLayout structures.
 //
 // During interpretation, if profiling in enabled, the interpreter
 // maintains a method data pointer (mdp), which points at the entry
 // in the array corresponding to the current bci.  In the course of
 // intepretation, when a bytecode is encountered that has profile data
 // associated with it, the entry pointed to by mdp is updated, then the
 // mdp is adjusted to point to the next appropriate DataLayout.  If mdp
 // is NULL to begin with, the interpreter assumes that the current method
 // is not (yet) being profiled.
 //
 // In MethodData* parlance, "dp" is a "data pointer", the actual address
 // of a DataLayout element.  A "di" is a "data index", the offset in bytes
 // from the base of the data entry array.  A "displacement" is the byte offset
 // in certain ProfileData objects that indicate the amount the mdp must be
 // adjusted in the event of a change in control flow.
 //
 class MethodData : public Metadata {
   friend class VMStructs;
 private:
   friend class ProfileData;
   // Back pointer to the Method*
   Method* _method;
   // Size of this oop in bytes
   int _size;
   // Cached hint for bci_to_dp and bci_to_data
   int _hint_di;
   MethodData(methodHandle method, int size, TRAPS);
 public:
   static MethodData* allocate(ClassLoaderData* loader_data, methodHandle method, TRAPS);
   MethodData() {}; // For ciMethodData
   bool is_methodData() const volatile { return true; }
   // Whole-method sticky bits and flags
   enum {
     _trap_hist_limit    = 18,   // decoupled from Deoptimization::Reason_LIMIT
     _trap_hist_mask     = max_jubyte,
     _extra_data_count   = 4     // extra DataLayout headers, for trap history
   }; // Public flag values
 private:
   uint _nof_decompiles;             // count of all nmethod removals
   uint _nof_overflow_recompiles;    // recompile count, excluding recomp. bits
   uint _nof_overflow_traps;         // trap count, excluding _trap_hist
   union {
     intptr_t _align;
     u1 _array[_trap_hist_limit];
   } _trap_hist;
   // Support for interprocedural escape analysis, from Thomas Kotzmann.
   intx              _eflags;          // flags on escape information
   intx              _arg_local;       // bit set of non-escaping arguments
   intx              _arg_stack;       // bit set of stack-allocatable arguments
   intx              _arg_returned;    // bit set of returned arguments
   int _creation_mileage;              // method mileage at MDO creation
   // How many invocations has this MDO seen?
   // These counters are used to determine the exact age of MDO.
   // We need those because in tiered a method can be concurrently
   // executed at different levels.
   InvocationCounter _invocation_counter;
   // Same for backedges.
   InvocationCounter _backedge_counter;
   // Counter values at the time profiling started.
   int               _invocation_counter_start;
   int               _backedge_counter_start;
   // Number of loops and blocks is computed when compiling the first
   // time with C1. It is used to determine if method is trivial.
   short             _num_loops;
   short             _num_blocks;
   // Highest compile level this method has ever seen.
   u1                _highest_comp_level;
   // Same for OSR level
   u1                _highest_osr_comp_level;
   // Does this method contain anything worth profiling?
   bool              _would_profile;
   // Size of _data array in bytes.  (Excludes header and extra_data fields.)
   int _data_size;
   // data index for the area dedicated to parameters. -1 if no
   // parameter profiling.
   int _parameters_type_data_di;
   // Beginning of the data entries
   intptr_t _data[1];
   // Helper for size computation
   static int compute_data_size(BytecodeStream* stream);
   static int bytecode_cell_count(Bytecodes::Code code);
   static bool is_speculative_trap_bytecode(Bytecodes::Code code);
   enum { no_profile_data = -1, variable_cell_count = -2 };
   // Helper for initialization
   DataLayout* data_layout_at(int data_index) const {
     assert(data_index % sizeof(intptr_t) == 0, "unaligned");
     return (DataLayout*) (((address)_data) + data_index);
   }
   // Initialize an individual data segment.  Returns the size of
   // the segment in bytes.
   int initialize_data(BytecodeStream* stream, int data_index);
   // Helper for data_at
   DataLayout* limit_data_position() const {
     return (DataLayout*)((address)data_base() + _data_size);
   }
   bool out_of_bounds(int data_index) const {
     return data_index >= data_size();
   }
   // Give each of the data entries a chance to perform specific
   // data initialization.
   void post_initialize(BytecodeStream* stream);
   // hint accessors
   int      hint_di() const  { return _hint_di; }
   void set_hint_di(int di)  {
     assert(!out_of_bounds(di), "hint_di out of bounds");
     _hint_di = di;
   }
   ProfileData* data_before(int bci) {
     // avoid SEGV on this edge case
     if (data_size() == 0)
       return NULL;
     int hint = hint_di();
     if (data_layout_at(hint)->bci() <= bci)
       return data_at(hint);
     return first_data();
   }
   // What is the index of the first data entry?
   int first_di() const { return 0; }
   ProfileData* bci_to_extra_data_helper(int bci, Method* m, DataLayout*& dp);
   // Find or create an extra ProfileData:
   ProfileData* bci_to_extra_data(int bci, Method* m, bool create_if_missing);
   // return the argument info cell
   ArgInfoData *arg_info();
   enum {
     no_type_profile = 0,
     type_profile_jsr292 = 1,
     type_profile_all = 2
   };
   static bool profile_jsr292(methodHandle m, int bci);
   static int profile_arguments_flag();
   static bool profile_arguments_jsr292_only();
   static bool profile_all_arguments();
   static bool profile_arguments_for_invoke(methodHandle m, int bci);
   static int profile_return_flag();
   static bool profile_all_return();
   static bool profile_return_for_invoke(methodHandle m, int bci);
   static int profile_parameters_flag();
   static bool profile_parameters_jsr292_only();
   static bool profile_all_parameters();
   void clean_extra_data(BoolObjectClosure* is_alive);
   void clean_extra_data_helper(DataLayout* dp, int shift, bool reset = false);
   void verify_extra_data_clean(BoolObjectClosure* is_alive);
 public:
   static int header_size() {
     return sizeof(MethodData)/wordSize;
   }
   // Compute the size of a MethodData* before it is created.
   static int compute_allocation_size_in_bytes(methodHandle method);
   static int compute_allocation_size_in_words(methodHandle method);
   static int compute_extra_data_count(int data_size, int empty_bc_count, bool needs_speculative_traps);
   // Determine if a given bytecode can have profile information.
   static bool bytecode_has_profile(Bytecodes::Code code) {
     return bytecode_cell_count(code) != no_profile_data;
   }
   // reset into original state
   void init();
   // My size
   int size_in_bytes() const { return _size; }
   int size() const    { return align_object_size(align_size_up(_size, BytesPerWord)/BytesPerWord); }
 #if INCLUDE_SERVICES
   void collect_statistics(KlassSizeStats *sz) const;
 #endif
   int      creation_mileage() const  { return _creation_mileage; }
   void set_creation_mileage(int x)   { _creation_mileage = x; }
   int invocation_count() {
     if (invocation_counter()->carry()) {
       return InvocationCounter::count_limit;
     }
     return invocation_counter()->count();
   }
   int backedge_count() {
     if (backedge_counter()->carry()) {
       return InvocationCounter::count_limit;
     }
     return backedge_counter()->count();
   }
   int invocation_count_start() {
     if (invocation_counter()->carry()) {
       return 0;
     }
     return _invocation_counter_start;
   }
   int backedge_count_start() {
     if (backedge_counter()->carry()) {
       return 0;
     }
     return _backedge_counter_start;
   }
   int invocation_count_delta() { return invocation_count() - invocation_count_start(); }
   int backedge_count_delta()   { return backedge_count()   - backedge_count_start();   }
   void reset_start_counters() {
     _invocation_counter_start = invocation_count();
     _backedge_counter_start = backedge_count();
   }
   InvocationCounter* invocation_counter()     { return &_invocation_counter; }
   InvocationCounter* backedge_counter()       { return &_backedge_counter;   }
   void set_would_profile(bool p)              { _would_profile = p;    }
   bool would_profile() const                  { return _would_profile; }
   int highest_comp_level() const              { return _highest_comp_level;      }
   void set_highest_comp_level(int level)      { _highest_comp_level = level;     }
   int highest_osr_comp_level() const          { return _highest_osr_comp_level;  }
   void set_highest_osr_comp_level(int level)  { _highest_osr_comp_level = level; }
   int num_loops() const                       { return _num_loops;  }
   void set_num_loops(int n)                   { _num_loops = n;     }
   int num_blocks() const                      { return _num_blocks; }
   void set_num_blocks(int n)                  { _num_blocks = n;    }
   bool is_mature() const;  // consult mileage and ProfileMaturityPercentage
   static int mileage_of(Method* m);
   // Support for interprocedural escape analysis, from Thomas Kotzmann.
   enum EscapeFlag {
     estimated    = 1 << 0,
     return_local = 1 << 1,
     return_allocated = 1 << 2,
     allocated_escapes = 1 << 3,
     unknown_modified = 1 << 4
   };
   intx eflags()                                  { return _eflags; }
   intx arg_local()                               { return _arg_local; }
   intx arg_stack()                               { return _arg_stack; }
   intx arg_returned()                            { return _arg_returned; }
   uint arg_modified(int a)                       { ArgInfoData *aid = arg_info();
                                                    assert(aid != NULL, "arg_info must be not null");
                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
                                                    return aid->arg_modified(a); }
   void set_eflags(intx v)                        { _eflags = v; }
   void set_arg_local(intx v)                     { _arg_local = v; }
   void set_arg_stack(intx v)                     { _arg_stack = v; }
   void set_arg_returned(intx v)                  { _arg_returned = v; }
   void set_arg_modified(int a, uint v)           { ArgInfoData *aid = arg_info();
                                                    assert(aid != NULL, "arg_info must be not null");
                                                    assert(a >= 0 && a < aid->number_of_args(), "valid argument number");
                                                    aid->set_arg_modified(a, v); }
   void clear_escape_info()                       { _eflags = _arg_local = _arg_stack = _arg_returned = 0; }
   // Location and size of data area
   address data_base() const {
     return (address) _data;
   }
   int data_size() const {
     return _data_size;
   }
   // Accessors
   Method* method() const { return _method; }
   // Get the data at an arbitrary (sort of) data index.
   ProfileData* data_at(int data_index) const;
   // Walk through the data in order.
   ProfileData* first_data() const { return data_at(first_di()); }
   ProfileData* next_data(ProfileData* current) const;
   bool is_valid(ProfileData* current) const { return current != NULL; }
   // Convert a dp (data pointer) to a di (data index).
   int dp_to_di(address dp) const {
     return dp - ((address)_data);
   }
   address di_to_dp(int di) {
     return (address)data_layout_at(di);
   }
   // bci to di/dp conversion.
   address bci_to_dp(int bci);
   int bci_to_di(int bci) {
     return dp_to_di(bci_to_dp(bci));
   }
   // Get the data at an arbitrary bci, or NULL if there is none.
   ProfileData* bci_to_data(int bci);
   // Same, but try to create an extra_data record if one is needed:
   ProfileData* allocate_bci_to_data(int bci, Method* m) {
     ProfileData* data = NULL;
     // If m not NULL, try to allocate a SpeculativeTrapData entry
     if (m == NULL) {
       data = bci_to_data(bci);
     }
     if (data != NULL) {
       return data;
     }
     data = bci_to_extra_data(bci, m, true);
     if (data != NULL) {
       return data;
     }
     // If SpeculativeTrapData allocation fails try to allocate a
     // regular entry
     data = bci_to_data(bci);
     if (data != NULL) {
       return data;
     }
     return bci_to_extra_data(bci, NULL, true);
   }
   // Add a handful of extra data records, for trap tracking.
   DataLayout* extra_data_base() const { return limit_data_position(); }
   DataLayout* extra_data_limit() const { return (DataLayout*)((address)this + size_in_bytes()); }
   int extra_data_size() const { return (address)extra_data_limit()
                                - (address)extra_data_base(); }
   static DataLayout* next_extra(DataLayout* dp);
   // Return (uint)-1 for overflow.
   uint trap_count(int reason) const {
     assert((uint)reason < _trap_hist_limit, "oob");
     return (int)((_trap_hist._array[reason]+1) & _trap_hist_mask) - 1;
   }
   // For loops:
   static uint trap_reason_limit() { return _trap_hist_limit; }
   static uint trap_count_limit()  { return _trap_hist_mask; }
   uint inc_trap_count(int reason) {
     // Count another trap, anywhere in this method.
     assert(reason >= 0, "must be single trap");
     if ((uint)reason < _trap_hist_limit) {
       uint cnt1 = 1 + _trap_hist._array[reason];
       if ((cnt1 & _trap_hist_mask) != 0) {  // if no counter overflow...
         _trap_hist._array[reason] = cnt1;
         return cnt1;
       } else {
         return _trap_hist_mask + (++_nof_overflow_traps);
       }
     } else {
       // Could not represent the count in the histogram.
       return (++_nof_overflow_traps);
     }
   }
   uint overflow_trap_count() const {
     return _nof_overflow_traps;
   }
   uint overflow_recompile_count() const {
     return _nof_overflow_recompiles;
   }
   void inc_overflow_recompile_count() {
     _nof_overflow_recompiles += 1;
   }
   uint decompile_count() const {
     return _nof_decompiles;
   }
   void inc_decompile_count() {
     _nof_decompiles += 1;
     if (decompile_count() > (uint)PerMethodRecompilationCutoff) {
       method()->set_not_compilable(CompLevel_full_optimization, true, "decompile_count > PerMethodRecompilationCutoff");
     }
   }
   // Return pointer to area dedicated to parameters in MDO
   ParametersTypeData* parameters_type_data() const {
     return _parameters_type_data_di != -1 ? data_layout_at(_parameters_type_data_di)->data_in()->as_ParametersTypeData() : NULL;
   }
   int parameters_type_data_di() const {
     assert(_parameters_type_data_di != -1, "no args type data");
     return _parameters_type_data_di;
   }
   // Support for code generation
   static ByteSize data_offset() {
     return byte_offset_of(MethodData, _data[0]);
   }
   static ByteSize invocation_counter_offset() {
     return byte_offset_of(MethodData, _invocation_counter);
   }
   static ByteSize backedge_counter_offset() {
     return byte_offset_of(MethodData, _backedge_counter);
   }
   static ByteSize parameters_type_data_di_offset() {
     return byte_offset_of(MethodData, _parameters_type_data_di);
   }
   // Deallocation support - no pointer fields to deallocate
   void deallocate_contents(ClassLoaderData* loader_data) {}
   // GC support
   void set_size(int object_size_in_bytes) { _size = object_size_in_bytes; }
   // Printing
 #ifndef PRODUCT
   void print_on      (outputStream* st) const;
 #endif
   void print_value_on(outputStream* st) const;
 #ifndef PRODUCT
   // printing support for method data
   void print_data_on(outputStream* st) const;
 #endif
   const char* internal_name() const { return "{method data}"; }
   // verification
   void verify_on(outputStream* st);
   void verify_data_on(outputStream* st);
   static bool profile_parameters_for_method(methodHandle m);
   static bool profile_arguments();
   static bool profile_return();
   static bool profile_parameters();
   static bool profile_return_jsr292_only();
   void clean_method_data(BoolObjectClosure* is_alive);
 };
 #endif // SHARE_VM_OOPS_METHODDATAOOP_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/methodData.hpp@b8413a9cbb84 (annotated)

src/share/vm/oops/methodData.hpp