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