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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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  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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  24 
  25 #ifndef SHARE_RUNTIME_DEOPTIMIZATION_HPP
  26 #define SHARE_RUNTIME_DEOPTIMIZATION_HPP
  27 
  28 #include "memory/allocation.hpp"
  29 #include "runtime/frame.hpp"
  30 
  31 class ProfileData;
  32 class vframeArray;
  33 class MonitorInfo;
  34 class MonitorValue;
  35 class ObjectValue;
  36 class ScopeValue;
  37 class compiledVFrame;
  38 
  39 template<class E> class GrowableArray;
  40 
  41 class Deoptimization : AllStatic {
  42   friend class VMStructs;
  43 
  44  public:
  45   // What condition caused the deoptimization?
  46   enum DeoptReason {
  47     Reason_many = -1,             // indicates presence of several reasons
  48     Reason_none = 0,              // indicates absence of a relevant deopt.
  49     // Next 8 reasons are recorded per bytecode in DataLayout::trap_bits.
  50     // This is more complicated for JVMCI as JVMCI may deoptimize to *some* bytecode before the
  51     // bytecode that actually caused the deopt (with inlining, JVMCI may even deoptimize to a
  52     // bytecode in another method):
  53     //  - bytecode y in method b() causes deopt
  54     //  - JVMCI deoptimizes to bytecode x in method a()
  55     // -> the deopt reason will be recorded for method a() at bytecode x
  56     Reason_null_check,            // saw unexpected null or zero divisor (@bci)
  57     Reason_null_assert,           // saw unexpected non-null or non-zero (@bci)
  58     Reason_range_check,           // saw unexpected array index (@bci)
  59     Reason_class_check,           // saw unexpected object class (@bci)
  60     Reason_array_check,           // saw unexpected array class (aastore @bci)
  61     Reason_intrinsic,             // saw unexpected operand to intrinsic (@bci)
  62     Reason_bimorphic,             // saw unexpected object class in bimorphic inlining (@bci)
  63 
  64 #if INCLUDE_JVMCI
  65     Reason_unreached0             = Reason_null_assert,
  66     Reason_type_checked_inlining  = Reason_intrinsic,
  67     Reason_optimized_type_check   = Reason_bimorphic,
  68 #endif
  69 
  70     Reason_profile_predicate,     // compiler generated predicate moved from frequent branch in a loop failed
  71 
  72     // recorded per method
  73     Reason_unloaded,              // unloaded class or constant pool entry
  74     Reason_uninitialized,         // bad class state (uninitialized)
  75     Reason_initialized,           // class has been fully initialized
  76     Reason_unreached,             // code is not reached, compiler
  77     Reason_unhandled,             // arbitrary compiler limitation
  78     Reason_constraint,            // arbitrary runtime constraint violated
  79     Reason_div0_check,            // a null_check due to division by zero
  80     Reason_age,                   // nmethod too old; tier threshold reached
  81     Reason_predicate,             // compiler generated predicate failed
  82     Reason_loop_limit_check,      // compiler generated loop limits check failed
  83     Reason_speculate_class_check, // saw unexpected object class from type speculation
  84     Reason_speculate_null_check,  // saw unexpected null from type speculation
  85     Reason_speculate_null_assert, // saw unexpected null from type speculation
  86     Reason_rtm_state_change,      // rtm state change detected
  87     Reason_unstable_if,           // a branch predicted always false was taken
  88     Reason_unstable_fused_if,     // fused two ifs that had each one untaken branch. One is now taken.
  89 #if INCLUDE_JVMCI
  90     Reason_aliasing,              // optimistic assumption about aliasing failed
  91     Reason_transfer_to_interpreter, // explicit transferToInterpreter()
  92     Reason_not_compiled_exception_handler,
  93     Reason_unresolved,
  94     Reason_jsr_mismatch,
  95 #endif
  96 
  97     // Reason_tenured is counted separately, add normal counted Reasons above.
  98     // Related to MethodData::_trap_hist_limit where Reason_tenured isn't included
  99     Reason_tenured,               // age of the code has reached the limit
 100     Reason_LIMIT,
 101 
 102     // Note:  Keep this enum in sync. with _trap_reason_name.
 103     Reason_RECORDED_LIMIT = Reason_profile_predicate  // some are not recorded per bc
 104     // Note:  Reason_RECORDED_LIMIT should fit into 31 bits of
 105     // DataLayout::trap_bits.  This dependency is enforced indirectly
 106     // via asserts, to avoid excessive direct header-to-header dependencies.
 107     // See Deoptimization::trap_state_reason and class DataLayout.
 108   };
 109 
 110   // What action must be taken by the runtime?
 111   enum DeoptAction {
 112     Action_none,                  // just interpret, do not invalidate nmethod
 113     Action_maybe_recompile,       // recompile the nmethod; need not invalidate
 114     Action_reinterpret,           // invalidate the nmethod, reset IC, maybe recompile
 115     Action_make_not_entrant,      // invalidate the nmethod, recompile (probably)
 116     Action_make_not_compilable,   // invalidate the nmethod and do not compile
 117     Action_LIMIT
 118     // Note:  Keep this enum in sync. with _trap_action_name.
 119   };
 120 
 121   enum {
 122     _action_bits = 3,
 123     _reason_bits = 5,
 124     _debug_id_bits = 23,
 125     _action_shift = 0,
 126     _reason_shift = _action_shift+_action_bits,
 127     _debug_id_shift = _reason_shift+_reason_bits,
 128     BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
 129   };
 130 
 131   enum UnpackType {
 132     Unpack_deopt                = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
 133     Unpack_exception            = 1, // exception is pending
 134     Unpack_uncommon_trap        = 2, // redo last byte code (C2 only)
 135     Unpack_reexecute            = 3, // reexecute bytecode (C1 only)
 136     Unpack_LIMIT                = 4
 137   };
 138 
 139   static void deoptimize_all_marked();
 140 
 141  private:
 142   // Checks all compiled methods. Invalid methods are deleted and
 143   // corresponding activations are deoptimized.
 144   static int deoptimize_dependents();
 145   static void revoke_using_handshake(JavaThread* thread, frame fr, RegisterMap* map);
 146   static void revoke_using_safepoint(JavaThread* thread, frame fr, RegisterMap* map);
 147   static void deopt_thread(bool in_handshake, JavaThread* thread, frame fr, RegisterMap *map, DeoptReason reason);
 148 
 149  public:
 150   // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
 151   static void deoptimize(JavaThread* thread, frame fr, RegisterMap *map, bool in_handshake = false);
 152   static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map, DeoptReason reason);
 153 
 154 #if INCLUDE_JVMCI
 155   static address deoptimize_for_missing_exception_handler(CompiledMethod* cm);
 156 #endif
 157 
 158   private:
 159   // Does the actual work for deoptimizing a single frame
 160   static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason);
 161 
 162   // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
 163   // is enabled
 164   static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
 165     revoke_using_safepoint(thread, fr, map);
 166   }
 167 
 168 #if COMPILER2_OR_JVMCI
 169 JVMCI_ONLY(public:)
 170 
 171   // Support for restoring non-escaping objects
 172   static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
 173   static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
 174   static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
 175   static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal);
 176   static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures);
 177   static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
 178   NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);)
 179 #endif // COMPILER2_OR_JVMCI
 180 
 181   public:
 182   static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
 183 
 184   // Interface used for unpacking deoptimized frames
 185 
 186   // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
 187   // This is only a CheapObj to ease debugging after a deopt failure
 188   class UnrollBlock : public CHeapObj<mtCompiler> {
 189     friend class VMStructs;
 190     friend class JVMCIVMStructs;
 191    private:
 192     int       _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
 193     int       _caller_adjustment;         // Adjustment, in bytes, to caller's SP by initial interpreted frame
 194     int       _number_of_frames;          // Number frames to unroll
 195     int       _total_frame_sizes;         // Total of number*sizes frames
 196     intptr_t* _frame_sizes;               // Array of frame sizes, in bytes, for unrolling the stack
 197     address*  _frame_pcs;                 // Array of frame pc's, in bytes, for unrolling the stack
 198     intptr_t* _register_block;            // Block for storing callee-saved registers.
 199     BasicType _return_type;               // Tells if we have to restore double or long return value
 200     intptr_t  _initial_info;              // Platform dependent data for the sender frame (was FP on x86)
 201     int       _caller_actual_parameters;  // The number of actual arguments at the
 202                                           // interpreted caller of the deoptimized frame
 203     int       _unpack_kind;               // exec_mode that can be changed during fetch_unroll_info
 204 
 205     // The following fields are used as temps during the unpacking phase
 206     // (which is tight on registers, especially on x86). They really ought
 207     // to be PD variables but that involves moving this class into its own
 208     // file to use the pd include mechanism. Maybe in a later cleanup ...
 209     intptr_t  _counter_temp;              // SHOULD BE PD VARIABLE (x86 frame count temp)
 210     intptr_t  _sender_sp_temp;            // SHOULD BE PD VARIABLE (x86 sender_sp)
 211    public:
 212     // Constructor
 213     UnrollBlock(int  size_of_deoptimized_frame,
 214                 int  caller_adjustment,
 215                 int  caller_actual_parameters,
 216                 int  number_of_frames,
 217                 intptr_t* frame_sizes,
 218                 address* frames_pcs,
 219                 BasicType return_type,
 220                 int unpack_kind);
 221     ~UnrollBlock();
 222 
 223     // Returns where a register is located.
 224     intptr_t* value_addr_at(int register_number) const;
 225 
 226     // Accessors
 227     intptr_t* frame_sizes()  const { return _frame_sizes; }
 228     int number_of_frames()  const { return _number_of_frames; }
 229     address*  frame_pcs()   const { return _frame_pcs ; }
 230     int  unpack_kind()   const { return _unpack_kind; }
 231 
 232     // Returns the total size of frames
 233     int size_of_frames() const;
 234 
 235     void set_initial_info(intptr_t info) { _initial_info = info; }
 236 
 237     int caller_actual_parameters() const { return _caller_actual_parameters; }
 238 
 239     // Accessors used by the code generator for the unpack stub.
 240     static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
 241     static int caller_adjustment_offset_in_bytes()         { return offset_of(UnrollBlock, _caller_adjustment);         }
 242     static int number_of_frames_offset_in_bytes()          { return offset_of(UnrollBlock, _number_of_frames);          }
 243     static int frame_sizes_offset_in_bytes()               { return offset_of(UnrollBlock, _frame_sizes);               }
 244     static int total_frame_sizes_offset_in_bytes()         { return offset_of(UnrollBlock, _total_frame_sizes);         }
 245     static int frame_pcs_offset_in_bytes()                 { return offset_of(UnrollBlock, _frame_pcs);                 }
 246     static int register_block_offset_in_bytes()            { return offset_of(UnrollBlock, _register_block);            }
 247     static int return_type_offset_in_bytes()               { return offset_of(UnrollBlock, _return_type);               }
 248     static int counter_temp_offset_in_bytes()              { return offset_of(UnrollBlock, _counter_temp);              }
 249     static int initial_info_offset_in_bytes()              { return offset_of(UnrollBlock, _initial_info);              }
 250     static int unpack_kind_offset_in_bytes()               { return offset_of(UnrollBlock, _unpack_kind);               }
 251     static int sender_sp_temp_offset_in_bytes()            { return offset_of(UnrollBlock, _sender_sp_temp);            }
 252 
 253     BasicType return_type() const { return _return_type; }
 254     void print();
 255   };
 256 
 257   //** Returns an UnrollBlock continuing information
 258   // how to make room for the resulting interpreter frames.
 259   // Called by assembly stub after execution has returned to
 260   // deoptimized frame.
 261   // @argument thread.     Thread where stub_frame resides.
 262   // @see OptoRuntime::deoptimization_fetch_unroll_info_C
 263   static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode);
 264 
 265   //** Unpacks vframeArray onto execution stack
 266   // Called by assembly stub after execution has returned to
 267   // deoptimized frame and after the stack unrolling.
 268   // @argument thread.     Thread where stub_frame resides.
 269   // @argument exec_mode.  Determines how execution should be continued in top frame.
 270   //                       0 means continue after current byte code
 271   //                       1 means exception has happened, handle exception
 272   //                       2 means reexecute current bytecode (for uncommon traps).
 273   // @see OptoRuntime::deoptimization_unpack_frames_C
 274   // Return BasicType of call return type, if any
 275   static BasicType unpack_frames(JavaThread* thread, int exec_mode);
 276 
 277   // Cleans up deoptimization bits on thread after unpacking or in the
 278   // case of an exception.
 279   static void cleanup_deopt_info(JavaThread  *thread,
 280                                  vframeArray * array);
 281 
 282   // Restores callee saved values from deoptimized frame into oldest interpreter frame
 283   // so caller of the deoptimized frame will get back the values it expects.
 284   static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
 285 
 286   //** Performs an uncommon trap for compiled code.
 287   // The top most compiler frame is converted into interpreter frames
 288   static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode);
 289   // Helper routine that enters the VM and may block
 290   static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
 291 
 292   //** Deoptimizes the frame identified by id.
 293   // Only called from VMDeoptimizeFrame
 294   // @argument thread.     Thread where stub_frame resides.
 295   // @argument id.         id of frame that should be deoptimized.
 296   static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
 297 
 298   // if thread is not the current thread then execute
 299   // VM_DeoptimizeFrame otherwise deoptimize directly.
 300   static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
 301   static void deoptimize_frame(JavaThread* thread, intptr_t* id);
 302 
 303   // Statistics
 304   static void gather_statistics(DeoptReason reason, DeoptAction action,
 305                                 Bytecodes::Code bc = Bytecodes::_illegal);
 306   static void print_statistics();
 307 
 308   // How much room to adjust the last frame's SP by, to make space for
 309   // the callee's interpreter frame (which expects locals to be next to
 310   // incoming arguments)
 311   static int last_frame_adjust(int callee_parameters, int callee_locals);
 312 
 313   // trap_request codes
 314   static DeoptReason trap_request_reason(int trap_request) {
 315     if (trap_request < 0)
 316       return (DeoptReason)
 317         ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
 318     else
 319       // standard reason for unloaded CP entry
 320       return Reason_unloaded;
 321   }
 322   static DeoptAction trap_request_action(int trap_request) {
 323     if (trap_request < 0)
 324       return (DeoptAction)
 325         ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
 326     else
 327       // standard action for unloaded CP entry
 328       return _unloaded_action;
 329   }
 330   static int trap_request_debug_id(int trap_request) {
 331     if (trap_request < 0) {
 332       return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits));
 333     } else {
 334       // standard action for unloaded CP entry
 335       return 0;
 336     }
 337   }
 338   static int trap_request_index(int trap_request) {
 339     if (trap_request < 0)
 340       return -1;
 341     else
 342       return trap_request;
 343   }
 344   static int make_trap_request(DeoptReason reason, DeoptAction action,
 345                                int index = -1) {
 346     assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
 347     assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
 348     int trap_request;
 349     if (index != -1)
 350       trap_request = index;
 351     else
 352       trap_request = (~(((reason) << _reason_shift)
 353                         + ((action) << _action_shift)));
 354     assert(reason == trap_request_reason(trap_request), "valid reason");
 355     assert(action == trap_request_action(trap_request), "valid action");
 356     assert(index  == trap_request_index(trap_request),  "valid index");
 357     return trap_request;
 358   }
 359 
 360   // The trap_state stored in a MDO is decoded here.
 361   // It records two items of information.
 362   //  reason:  If a deoptimization happened here, what its reason was,
 363   //           or if there were multiple deopts with differing reasons.
 364   //  recompiled: If a deoptimization here triggered a recompilation.
 365   // Note that not all reasons are recorded per-bci.
 366   static DeoptReason trap_state_reason(int trap_state);
 367   static int  trap_state_has_reason(int trap_state, int reason);
 368   static int  trap_state_add_reason(int trap_state, int reason);
 369   static bool trap_state_is_recompiled(int trap_state);
 370   static int  trap_state_set_recompiled(int trap_state, bool z);
 371   static const char* format_trap_state(char* buf, size_t buflen,
 372                                        int trap_state);
 373 
 374   static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
 375     return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
 376   }
 377 
 378   static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
 379     if (reason_is_recorded_per_bytecode(reason))
 380       return reason;
 381     else if (reason == Reason_div0_check) // null check due to divide-by-zero?
 382       return Reason_null_check;           // recorded per BCI as a null check
 383     else if (reason == Reason_speculate_class_check)
 384       return Reason_class_check;
 385     else if (reason == Reason_speculate_null_check)
 386       return Reason_null_check;
 387     else if (reason == Reason_speculate_null_assert)
 388       return Reason_null_assert;
 389     else if (reason == Reason_unstable_if)
 390       return Reason_intrinsic;
 391     else if (reason == Reason_unstable_fused_if)
 392       return Reason_range_check;
 393     else
 394       return Reason_none;
 395   }
 396 
 397   static bool reason_is_speculate(int reason) {
 398     if (reason == Reason_speculate_class_check ||
 399         reason == Reason_speculate_null_check ||
 400         reason == Reason_speculate_null_assert) {
 401       return true;
 402     }
 403     return false;
 404   }
 405 
 406   static DeoptReason reason_null_check(bool speculative) {
 407     return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
 408   }
 409 
 410   static DeoptReason reason_class_check(bool speculative) {
 411     return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
 412   }
 413 
 414   static DeoptReason reason_null_assert(bool speculative) {
 415     return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert;
 416   }
 417 
 418   static uint per_method_trap_limit(int reason) {
 419     return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
 420   }
 421 
 422   static const char* trap_reason_name(int reason);
 423   static const char* trap_action_name(int action);
 424   // Format like reason='foo' action='bar' index='123'.
 425   // This is suitable both for XML and for tty output.
 426   static const char* format_trap_request(char* buf, size_t buflen,
 427                                          int trap_request);
 428 
 429   static jint total_deoptimization_count();
 430 
 431   // JVMTI PopFrame support
 432 
 433   // Preserves incoming arguments to the popped frame when it is
 434   // returning to a deoptimized caller
 435   static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
 436 
 437   static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing);
 438  private:
 439   // Update the mdo's count and per-BCI reason bits, returning previous state:
 440   static ProfileData* query_update_method_data(MethodData* trap_mdo,
 441                                                int trap_bci,
 442                                                DeoptReason reason,
 443                                                bool update_total_trap_count,
 444 #if INCLUDE_JVMCI
 445                                                bool is_osr,
 446 #endif
 447                                                Method* compiled_method,
 448                                                //outputs:
 449                                                uint& ret_this_trap_count,
 450                                                bool& ret_maybe_prior_trap,
 451                                                bool& ret_maybe_prior_recompile);
 452   // class loading support for uncommon trap
 453   static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
 454   static void load_class_by_index(const constantPoolHandle& constant_pool, int index);
 455 
 456   static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode);
 457 
 458   static DeoptAction _unloaded_action; // == Action_reinterpret;
 459   static const char* _trap_reason_name[];
 460   static const char* _trap_action_name[];
 461 
 462   static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
 463   // Note:  Histogram array size is 1-2 Kb.
 464 
 465  public:
 466   static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
 467 };
 468 
 469 class DeoptimizationMarker : StackObj {  // for profiling
 470   static bool _is_active;
 471 public:
 472   DeoptimizationMarker()  { _is_active = true; }
 473   ~DeoptimizationMarker() { _is_active = false; }
 474   static bool is_active() { return _is_active; }
 475 };
 476 
 477 #endif // SHARE_RUNTIME_DEOPTIMIZATION_HPP