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