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 /*

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  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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  * 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

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  */

 class ProfileData;

 class vframeArray;

 class MonitorValue;

 class ObjectValue;

 class Deoptimization : AllStatic {

  public:

   // What condition caused the deoptimization?

   enum DeoptReason {

     Reason_many = -1,             // indicates presence of several reasons

     Reason_none = 0,              // indicates absence of a relevant deopt.

     // Next 7 reasons are recorded per bytecode in DataLayout::trap_bits

     Reason_null_check,            // saw unexpected null or zero divisor (@bci)

     Reason_null_assert,           // saw unexpected non-null or non-zero (@bci)

     Reason_range_check,           // saw unexpected array index (@bci)

     Reason_class_check,           // saw unexpected object class (@bci)

     Reason_array_check,           // saw unexpected array class (aastore @bci)

     Reason_intrinsic,             // saw unexpected operand to intrinsic (@bci)

     Reason_bimorphic,             // saw unexpected object class in bimorphic inlining (@bci)

     Reason_unloaded,              // unloaded class or constant pool entry

     Reason_uninitialized,         // bad class state (uninitialized)

     Reason_unreached,             // code is not reached, compiler

     Reason_unhandled,             // arbitrary compiler limitation

     Reason_constraint,            // arbitrary runtime constraint violated

     Reason_div0_check,            // a null_check due to division by zero

     Reason_age,                   // nmethod too old; tier threshold reached

     Reason_predicate,             // compiler generated predicate failed

     Reason_LIMIT,

     // Note:  Keep this enum in sync. with _trap_reason_name.

     Reason_RECORDED_LIMIT = Reason_bimorphic  // some are not recorded per bc

     // Note:  Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of

     // DataLayout::trap_bits.  This dependency is enforced indirectly

     // via asserts, to avoid excessive direct header-to-header dependencies.

     // See Deoptimization::trap_state_reason and class DataLayout.

   };

   // What action must be taken by the runtime?

   enum DeoptAction {

     Action_none,                  // just interpret, do not invalidate nmethod

     Action_maybe_recompile,       // recompile the nmethod; need not invalidate

     Action_reinterpret,           // invalidate the nmethod, reset IC, maybe recompile

     Action_make_not_entrant,      // invalidate the nmethod, recompile (probably)

     Action_make_not_compilable,   // invalidate the nmethod and do not compile

     Action_LIMIT

     // Note:  Keep this enum in sync. with _trap_action_name.

   };

   enum {

     _action_bits = 3,

     _reason_bits = 4,

     _action_shift = 0,

     _reason_shift = _action_shift+_action_bits,

     BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist

   };

   enum UnpackType {

     Unpack_deopt                = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack

     Unpack_exception            = 1, // exception is pending

     Unpack_uncommon_trap        = 2, // redo last byte code (C2 only)

     Unpack_reexecute            = 3  // reexecute bytecode (C1 only)

   };

   // Checks all compiled methods. Invalid methods are deleted and

   // corresponding activations are deoptimized.

   static int deoptimize_dependents();

   // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame

   static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);

   private:

   // Does the actual work for deoptimizing a single frame

   static void deoptimize_single_frame(JavaThread* thread, frame fr);

   // Helper function to revoke biases of all monitors in frame if UseBiasedLocking

   // is enabled

   static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);

   // Helper function to revoke biases of all monitors in frames

   // executing in a particular CodeBlob if UseBiasedLocking is enabled

   static void revoke_biases_of_monitors(CodeBlob* cb);

 #ifdef COMPILER2

   // Support for restoring non-escaping objects

   static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);

   static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);

   static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);

   static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);

   static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread);

   NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)

 #endif // COMPILER2

   public:

   static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);

   // Interface used for unpacking deoptimized frames

   // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).

   // This is only a CheapObj to ease debugging after a deopt failure

   class UnrollBlock : public CHeapObj {

    private:

     int       _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame

     int       _caller_adjustment;         // Adjustment, in bytes, to caller's SP by initial interpreted frame

     int       _number_of_frames;          // Number frames to unroll

     int       _total_frame_sizes;         // Total of number*sizes frames

     intptr_t* _frame_sizes;               // Array of frame sizes, in bytes, for unrolling the stack

     address*  _frame_pcs;                 // Array of frame pc's, in bytes, for unrolling the stack

     intptr_t* _register_block;            // Block for storing callee-saved registers.

     BasicType _return_type;               // Tells if we have to restore double or long return value

     // The following fields are used as temps during the unpacking phase

     // (which is tight on registers, especially on x86). They really ought

     // to be PD variables but that involves moving this class into its own

     // file to use the pd include mechanism. Maybe in a later cleanup ...

     intptr_t  _counter_temp;              // SHOULD BE PD VARIABLE (x86 frame count temp)

     intptr_t  _initial_fp;                // SHOULD BE PD VARIABLE (x86/c2 initial ebp)

     intptr_t  _unpack_kind;               // SHOULD BE PD VARIABLE (x86 unpack kind)

     intptr_t  _sender_sp_temp;            // SHOULD BE PD VARIABLE (x86 sender_sp)

    public:

     // Constructor

     UnrollBlock(int  size_of_deoptimized_frame,

                 int  caller_adjustment,

                 int  number_of_frames,

                 intptr_t* frame_sizes,

                 address* frames_pcs,

                 BasicType return_type);

     ~UnrollBlock();

     // Returns where a register is located.

     intptr_t* value_addr_at(int register_number) const;

     // Accessors

     intptr_t* frame_sizes()  const { return _frame_sizes; }

     int number_of_frames()  const { return _number_of_frames; }

     address*  frame_pcs()   const { return _frame_pcs ; }

     // Returns the total size of frames

     int size_of_frames() const;

     // Accessors used by the code generator for the unpack stub.

     static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }

     static int caller_adjustment_offset_in_bytes()         { return offset_of(UnrollBlock, _caller_adjustment);         }

     static int number_of_frames_offset_in_bytes()          { return offset_of(UnrollBlock, _number_of_frames);          }

     static int frame_sizes_offset_in_bytes()               { return offset_of(UnrollBlock, _frame_sizes);               }

     static int total_frame_sizes_offset_in_bytes()         { return offset_of(UnrollBlock, _total_frame_sizes);         }

     static int frame_pcs_offset_in_bytes()                 { return offset_of(UnrollBlock, _frame_pcs);                 }

     static int register_block_offset_in_bytes()            { return offset_of(UnrollBlock, _register_block);            }

     static int return_type_offset_in_bytes()               { return offset_of(UnrollBlock, _return_type);               }

     static int counter_temp_offset_in_bytes()              { return offset_of(UnrollBlock, _counter_temp);              }

     static int initial_fp_offset_in_bytes()                { return offset_of(UnrollBlock, _initial_fp);                }

     static int unpack_kind_offset_in_bytes()               { return offset_of(UnrollBlock, _unpack_kind);               }

     static int sender_sp_temp_offset_in_bytes()            { return offset_of(UnrollBlock, _sender_sp_temp);            }

     BasicType return_type() const { return _return_type; }

     void print();

   };

   //** Returns an UnrollBlock continuing information

   // how to make room for the resulting interpreter frames.

   // Called by assembly stub after execution has returned to

   // deoptimized frame.

   // @argument thread.     Thread where stub_frame resides.

   // @see OptoRuntime::deoptimization_fetch_unroll_info_C

   static UnrollBlock* fetch_unroll_info(JavaThread* thread);

   //** Unpacks vframeArray onto execution stack

   // Called by assembly stub after execution has returned to

   // deoptimized frame and after the stack unrolling.

   // @argument thread.     Thread where stub_frame resides.

   // @argument exec_mode.  Determines how execution should be continuted in top frame.

   //                       0 means continue after current byte code

   //                       1 means exception has happened, handle exception

   //                       2 means reexecute current bytecode (for uncommon traps).

   // @see OptoRuntime::deoptimization_unpack_frames_C

   // Return BasicType of call return type, if any

   static BasicType unpack_frames(JavaThread* thread, int exec_mode);

   // Cleans up deoptimization bits on thread after unpacking or in the

   // case of an exception.

   static void cleanup_deopt_info(JavaThread  *thread,

                                  vframeArray * array);

   // Restores callee saved values from deoptimized frame into oldest interpreter frame

   // so caller of the deoptimized frame will get back the values it expects.

   static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);

   //** Performs an uncommon trap for compiled code.

   // The top most compiler frame is converted into interpreter frames

   static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);

   // Helper routine that enters the VM and may block

   static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);

   //** Deoptimizes the frame identified by id.

   // Only called from VMDeoptimizeFrame

   // @argument thread.     Thread where stub_frame resides.

   // @argument id.         id of frame that should be deoptimized.

   static void deoptimize_frame(JavaThread* thread, intptr_t* id);

   // Statistics

   static void gather_statistics(DeoptReason reason, DeoptAction action,

                                 Bytecodes::Code bc = Bytecodes::_illegal);

   static void print_statistics();

   // How much room to adjust the last frame's SP by, to make space for

   // the callee's interpreter frame (which expects locals to be next to

   // incoming arguments)

   static int last_frame_adjust(int callee_parameters, int callee_locals);

   // trap_request codes

   static DeoptReason trap_request_reason(int trap_request) {

     if (trap_request < 0)

       return (DeoptReason)

         ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));

     else

       // standard reason for unloaded CP entry

       return Reason_unloaded;

   }

   static DeoptAction trap_request_action(int trap_request) {

     if (trap_request < 0)

       return (DeoptAction)

         ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));

     else

       // standard action for unloaded CP entry

       return _unloaded_action;

   }

   static int trap_request_index(int trap_request) {

     if (trap_request < 0)

       return -1;

     else

       return trap_request;

   }

   static int make_trap_request(DeoptReason reason, DeoptAction action,

                                int index = -1) {

     assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");

     assert((1 << _action_bits) >= Action_LIMIT, "enough bits");

     int trap_request;

     if (index != -1)

       trap_request = index;

     else

       trap_request = (~(((reason) << _reason_shift)

                         + ((action) << _action_shift)));

     assert(reason == trap_request_reason(trap_request), "valid reason");

     assert(action == trap_request_action(trap_request), "valid action");

     assert(index  == trap_request_index(trap_request),  "valid index");

     return trap_request;

   }

   // The trap_state stored in a MDO is decoded here.

   // It records two items of information.

   //  reason:  If a deoptimization happened here, what its reason was,

   //           or if there were multiple deopts with differing reasons.

   //  recompiled: If a deoptimization here triggered a recompilation.

   // Note that not all reasons are recorded per-bci.

   static DeoptReason trap_state_reason(int trap_state);

   static int  trap_state_has_reason(int trap_state, int reason);

   static int  trap_state_add_reason(int trap_state, int reason);

   static bool trap_state_is_recompiled(int trap_state);

   static int  trap_state_set_recompiled(int trap_state, bool z);

   static const char* format_trap_state(char* buf, size_t buflen,

                                        int trap_state);

   static bool reason_is_recorded_per_bytecode(DeoptReason reason) {

     return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;

   }

   static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {

     if (reason_is_recorded_per_bytecode(reason))

       return reason;

     else if (reason == Reason_div0_check) // null check due to divide-by-zero?

       return Reason_null_check;           // recorded per BCI as a null check

     else

       return Reason_none;

   }

   static const char* trap_reason_name(int reason);

   static const char* trap_action_name(int action);

   // Format like reason='foo' action='bar' index='123'.

   // This is suitable both for XML and for tty output.

   static const char* format_trap_request(char* buf, size_t buflen,

                                          int trap_request);

   static jint total_deoptimization_count();

   static jint deoptimization_count(DeoptReason reason);

   // JVMTI PopFrame support

   // Preserves incoming arguments to the popped frame when it is

   // returning to a deoptimized caller

   static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);

  private:

   static methodDataOop get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);

   // Update the mdo's count and per-BCI reason bits, returning previous state:

   static ProfileData* query_update_method_data(methodDataHandle trap_mdo,

                                                int trap_bci,

                                                DeoptReason reason,

                                                //outputs:

                                                uint& ret_this_trap_count,

                                                bool& ret_maybe_prior_trap,

                                                bool& ret_maybe_prior_recompile);

   // class loading support for uncommon trap

   static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);

   static void load_class_by_index(constantPoolHandle constant_pool, int index);

   static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);

   static DeoptAction _unloaded_action; // == Action_reinterpret;

   static const char* _trap_reason_name[Reason_LIMIT];

   static const char* _trap_action_name[Action_LIMIT];

   static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];

   // Note:  Histogram array size is 1-2 Kb.

  public:

   static void update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason);

 };

 class DeoptimizationMarker : StackObj {  // for profiling

   static bool _is_active;

 public:

   DeoptimizationMarker()  { _is_active = true; }

   ~DeoptimizationMarker() { _is_active = false; }

   static bool is_active() { return _is_active; }

 };