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24
25 #ifndef SHARE_RUNTIME_DEOPTIMIZATION_HPP
26 #define SHARE_RUNTIME_DEOPTIMIZATION_HPP
27
28 #include "interpreter/bytecodes.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/frame.hpp"
31
32 class ProfileData;
33 class vframeArray;
34 class MonitorInfo;
35 class MonitorValue;
36 class ObjectValue;
37 class AutoBoxObjectValue;
38 class ScopeValue;
39 class compiledVFrame;
40
41 template<class E> class GrowableArray;
42
43 class DeoptimizationScope {
44 private:
45 // What gen we have done the deopt handshake for.
46 static uint64_t _committed_deopt_gen;
47 // What gen to mark a method with, hence larger than _committed_deopt_gen.
48 static uint64_t _active_deopt_gen;
49 // Indicate an in-progress deopt handshake.
50 static bool _committing_in_progress;
51
52 // The required gen we need to execute/wait for
53 uint64_t _required_gen;
54 DEBUG_ONLY(bool _deopted;)
55
56 public:
57 DeoptimizationScope();
58 ~DeoptimizationScope();
59 // Mark a method, if already marked as dependent.
60 void mark(nmethod* nm, bool inc_recompile_counts = true);
61 // Record this as a dependent method.
62 void dependent(nmethod* nm);
63
64 // Execute the deoptimization.
65 // Make the nmethods not entrant, stackwalks and patch return pcs and sets post call nops.
66 void deoptimize_marked();
67 };
68
69 class Deoptimization : AllStatic {
70 friend class VMStructs;
71 friend class EscapeBarrier;
72
73 public:
74 // What condition caused the deoptimization?
75 // Note: Keep this enum in sync. with Deoptimization::_trap_reason_name.
76 enum DeoptReason {
77 Reason_many = -1, // indicates presence of several reasons
78 Reason_none = 0, // indicates absence of a relevant deopt.
79 // Next 8 reasons are recorded per bytecode in DataLayout::trap_bits.
80 // This is more complicated for JVMCI as JVMCI may deoptimize to *some* bytecode before the
81 // bytecode that actually caused the deopt (with inlining, JVMCI may even deoptimize to a
82 // bytecode in another method):
83 // - bytecode y in method b() causes deopt
84 // - JVMCI deoptimizes to bytecode x in method a()
85 // -> the deopt reason will be recorded for method a() at bytecode x
86 Reason_null_check, // saw unexpected null or zero divisor (@bci)
87 Reason_null_assert, // saw unexpected non-null or non-zero (@bci)
88 Reason_range_check, // saw unexpected array index (@bci)
89 Reason_class_check, // saw unexpected object class (@bci)
90 Reason_array_check, // saw unexpected array class (aastore @bci)
91 Reason_intrinsic, // saw unexpected operand to intrinsic (@bci)
92 Reason_bimorphic, // saw unexpected object class in bimorphic inlining (@bci)
93
94 #if INCLUDE_JVMCI
95 Reason_unreached0 = Reason_null_assert,
96 Reason_type_checked_inlining = Reason_intrinsic,
97 Reason_optimized_type_check = Reason_bimorphic,
98 #endif
99
100 Reason_profile_predicate, // compiler generated predicate moved from frequent branch in a loop failed
101
102 // recorded per method
103 Reason_unloaded, // unloaded class or constant pool entry
104 Reason_uninitialized, // bad class state (uninitialized)
105 Reason_initialized, // class has been fully initialized
106 Reason_unreached, // code is not reached, compiler
107 Reason_unhandled, // arbitrary compiler limitation
108 Reason_constraint, // arbitrary runtime constraint violated
109 Reason_div0_check, // a null_check due to division by zero
110 Reason_age, // nmethod too old; tier threshold reached
111 Reason_predicate, // compiler generated predicate failed
112 Reason_loop_limit_check, // compiler generated loop limits check failed
113 Reason_speculate_class_check, // saw unexpected object class from type speculation
114 Reason_speculate_null_check, // saw unexpected null from type speculation
115 Reason_speculate_null_assert, // saw unexpected null from type speculation
116 Reason_unstable_if, // a branch predicted always false was taken
117 Reason_unstable_fused_if, // fused two ifs that had each one untaken branch. One is now taken.
118 Reason_receiver_constraint, // receiver subtype check failed
119 #if INCLUDE_JVMCI
120 Reason_aliasing, // optimistic assumption about aliasing failed
121 Reason_transfer_to_interpreter, // explicit transferToInterpreter()
122 Reason_not_compiled_exception_handler,
123 Reason_unresolved,
124 Reason_jsr_mismatch,
125 #endif
126
127 // Used to define MethodData::_trap_hist_limit where Reason_tenured isn't included
128 Reason_TRAP_HISTORY_LENGTH,
129
130 // Reason_tenured is counted separately, add normal counted Reasons above.
131 Reason_tenured = Reason_TRAP_HISTORY_LENGTH, // age of the code has reached the limit
132 Reason_LIMIT,
133
134 // Note: Reason_RECORDED_LIMIT should fit into 31 bits of
135 // DataLayout::trap_bits. This dependency is enforced indirectly
136 // via asserts, to avoid excessive direct header-to-header dependencies.
137 // See Deoptimization::trap_state_reason and class DataLayout.
138 Reason_RECORDED_LIMIT = Reason_profile_predicate, // some are not recorded per bc
139 };
140
141 // What action must be taken by the runtime?
142 // Note: Keep this enum in sync. with Deoptimization::_trap_action_name.
143 enum DeoptAction {
144 Action_none, // just interpret, do not invalidate nmethod
145 Action_maybe_recompile, // recompile the nmethod; need not invalidate
146 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
147 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
148 Action_make_not_compilable, // invalidate the nmethod and do not compile
149 Action_LIMIT
150 };
151
152 enum {
153 _action_bits = 3,
154 _reason_bits = 5,
155 _debug_id_bits = 23,
156 _action_shift = 0,
157 _reason_shift = _action_shift+_action_bits,
158 _debug_id_shift = _reason_shift+_reason_bits,
159 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
160 };
161
162 enum UnpackType {
163 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
164 Unpack_exception = 1, // exception is pending
165 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
166 Unpack_reexecute = 3, // reexecute bytecode (C1 only)
167 Unpack_none = 4, // not deoptimizing the frame, just reallocating/relocking for JVMTI
168 Unpack_LIMIT = 5
169 };
170
171 #if INCLUDE_JVMCI
172 // Can reconstruct virtualized unsafe large accesses to byte arrays.
173 static const int _support_large_access_byte_array_virtualization = 1;
174 #endif
175
176 // Make all nmethods that are marked_for_deoptimization not_entrant and deoptimize any live
177 // activations using those nmethods. Scan of the code cache is done to
178 // find all marked nmethods and they are made not_entrant.
179 static void deoptimize_all_marked();
180
181 public:
182 // Deoptimizes a frame lazily. Deopt happens on return to the frame.
183 static void deoptimize(JavaThread* thread, frame fr, DeoptReason reason = Reason_constraint);
184
185 #if INCLUDE_JVMCI
186 static address deoptimize_for_missing_exception_handler(nmethod* nm);
187 static oop get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, bool& cache_init_error, TRAPS);
188 #endif
189
190 private:
191 // Does the actual work for deoptimizing a single frame
192 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason);
193
194 #if COMPILER2_OR_JVMCI
195 // Deoptimize objects, that is reallocate and relock them, just before they
196 // escape through JVMTI. The given vframes cover one physical frame.
197 static bool deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
198 bool& realloc_failures);
199
200 public:
201
202 // Support for restoring non-escaping objects
203 static bool realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS);
204 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
205 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
206 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal);
207 static bool relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
208 JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures);
209 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
210 #endif // COMPILER2_OR_JVMCI
211
212 public:
213 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
214
215 // Interface used for unpacking deoptimized frames
216
217 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
218 // This is only a CheapObj to ease debugging after a deopt failure
219 class UnrollBlock : public CHeapObj<mtCompiler> {
220 friend class VMStructs;
221 friend class JVMCIVMStructs;
222 private:
223 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
224 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
225 int _number_of_frames; // Number frames to unroll
226 int _total_frame_sizes; // Total of number*sizes frames
227 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
228 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
229 intptr_t* _register_block; // Block for storing callee-saved registers.
230 BasicType _return_type; // Tells if we have to restore double or long return value
231 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
232 int _caller_actual_parameters; // The number of actual arguments at the
233 // interpreted caller of the deoptimized frame
234 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info
235
236 // The following fields are used as temps during the unpacking phase
237 // (which is tight on registers, especially on x86). They really ought
238 // to be PD variables but that involves moving this class into its own
239 // file to use the pd include mechanism. Maybe in a later cleanup ...
240 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
241 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
242 public:
243 // Constructor
244 UnrollBlock(int size_of_deoptimized_frame,
245 int caller_adjustment,
246 int caller_actual_parameters,
247 int number_of_frames,
248 intptr_t* frame_sizes,
249 address* frames_pcs,
250 BasicType return_type,
251 int unpack_kind);
252 ~UnrollBlock();
253
254 // Accessors
255 intptr_t* frame_sizes() const { return _frame_sizes; }
256 int number_of_frames() const { return _number_of_frames; }
257
258 // Returns the total size of frames
259 int size_of_frames() const;
260
261 void set_initial_info(intptr_t info) { _initial_info = info; }
262
263 int caller_actual_parameters() const { return _caller_actual_parameters; }
264
265 // Accessors used by the code generator for the unpack stub.
266 static ByteSize size_of_deoptimized_frame_offset() { return byte_offset_of(UnrollBlock, _size_of_deoptimized_frame); }
267 static ByteSize caller_adjustment_offset() { return byte_offset_of(UnrollBlock, _caller_adjustment); }
268 static ByteSize number_of_frames_offset() { return byte_offset_of(UnrollBlock, _number_of_frames); }
269 static ByteSize frame_sizes_offset() { return byte_offset_of(UnrollBlock, _frame_sizes); }
270 static ByteSize total_frame_sizes_offset() { return byte_offset_of(UnrollBlock, _total_frame_sizes); }
271 static ByteSize frame_pcs_offset() { return byte_offset_of(UnrollBlock, _frame_pcs); }
272 static ByteSize counter_temp_offset() { return byte_offset_of(UnrollBlock, _counter_temp); }
273 static ByteSize initial_info_offset() { return byte_offset_of(UnrollBlock, _initial_info); }
274 static ByteSize unpack_kind_offset() { return byte_offset_of(UnrollBlock, _unpack_kind); }
275 static ByteSize sender_sp_temp_offset() { return byte_offset_of(UnrollBlock, _sender_sp_temp); }
276
277 BasicType return_type() const { return _return_type; }
278 void print();
279 };
280
281 //** Returns an UnrollBlock continuing information
282 // how to make room for the resulting interpreter frames.
283 // Called by assembly stub after execution has returned to
284 // deoptimized frame.
285 // @argument thread. Thread where stub_frame resides.
286 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
287 static UnrollBlock* fetch_unroll_info(JavaThread* current, int exec_mode);
288
289 //** Unpacks vframeArray onto execution stack
290 // Called by assembly stub after execution has returned to
291 // deoptimized frame and after the stack unrolling.
292 // @argument thread. Thread where stub_frame resides.
293 // @argument exec_mode. Determines how execution should be continued in top frame.
294 // 0 means continue after current byte code
295 // 1 means exception has happened, handle exception
296 // 2 means reexecute current bytecode (for uncommon traps).
297 // @see OptoRuntime::deoptimization_unpack_frames_C
298 // Return BasicType of call return type, if any
299 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
300
301 // Cleans up deoptimization bits on thread after unpacking or in the
302 // case of an exception.
303 static void cleanup_deopt_info(JavaThread *thread,
304 vframeArray * array);
305
306 // Restores callee saved values from deoptimized frame into oldest interpreter frame
307 // so caller of the deoptimized frame will get back the values it expects.
308 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
309
310 //** Performs an uncommon trap for compiled code.
311 // The top most compiler frame is converted into interpreter frames
312 static UnrollBlock* uncommon_trap(JavaThread* current, jint unloaded_class_index, jint exec_mode);
313 // Helper routine that enters the VM and may block
314 static void uncommon_trap_inner(JavaThread* current, jint unloaded_class_index);
315
316 //** Deoptimizes the frame identified by id.
317 // Only called from VMDeoptimizeFrame
318 // @argument thread. Thread where stub_frame resides.
319 // @argument id. id of frame that should be deoptimized.
320 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
321
322 // if thread is not the current thread then execute
323 // VM_DeoptimizeFrame otherwise deoptimize directly.
324 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
325 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
326
327 // Statistics
328 static void gather_statistics(DeoptReason reason, DeoptAction action,
329 Bytecodes::Code bc = Bytecodes::_illegal);
330 static void print_statistics();
331
332 // How much room to adjust the last frame's SP by, to make space for
333 // the callee's interpreter frame (which expects locals to be next to
334 // incoming arguments)
335 static int last_frame_adjust(int callee_parameters, int callee_locals);
336
337 // trap_request codes
338 static DeoptReason trap_request_reason(int trap_request) {
339 if (trap_request < 0)
340 return (DeoptReason)
341 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
342 else
343 // standard reason for unloaded CP entry
344 return Reason_unloaded;
345 }
346 static DeoptAction trap_request_action(int trap_request) {
347 if (trap_request < 0)
348 return (DeoptAction)
349 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
350 else
351 // standard action for unloaded CP entry
352 return _unloaded_action;
353 }
354 static int trap_request_debug_id(int trap_request) {
355 if (trap_request < 0) {
356 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits));
357 } else {
358 // standard action for unloaded CP entry
359 return 0;
360 }
361 }
362 static int trap_request_index(int trap_request) {
363 if (trap_request < 0)
364 return -1;
365 else
366 return trap_request;
367 }
368 static int make_trap_request(DeoptReason reason, DeoptAction action,
369 int index = -1) {
370 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
371 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
372 int trap_request;
373 if (index != -1)
374 trap_request = index;
375 else
376 trap_request = (~(((reason) << _reason_shift)
377 + ((action) << _action_shift)));
378 assert(reason == trap_request_reason(trap_request), "valid reason");
379 assert(action == trap_request_action(trap_request), "valid action");
380 assert(index == trap_request_index(trap_request), "valid index");
381 return trap_request;
382 }
383
384 // The trap_state stored in a MDO is decoded here.
385 // It records two items of information.
386 // reason: If a deoptimization happened here, what its reason was,
387 // or if there were multiple deopts with differing reasons.
388 // recompiled: If a deoptimization here triggered a recompilation.
389 // Note that not all reasons are recorded per-bci.
390 static DeoptReason trap_state_reason(int trap_state);
391 static int trap_state_has_reason(int trap_state, int reason);
392 static int trap_state_add_reason(int trap_state, int reason);
393 static bool trap_state_is_recompiled(int trap_state);
394 static int trap_state_set_recompiled(int trap_state, bool z);
395 static const char* format_trap_state(char* buf, size_t buflen,
396 int trap_state);
397
398 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
399 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
400 }
401
402 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
403 if (reason_is_recorded_per_bytecode(reason))
404 return reason;
405 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
406 return Reason_null_check; // recorded per BCI as a null check
407 else if (reason == Reason_speculate_class_check)
408 return Reason_class_check;
409 else if (reason == Reason_speculate_null_check)
410 return Reason_null_check;
411 else if (reason == Reason_speculate_null_assert)
412 return Reason_null_assert;
413 else if (reason == Reason_unstable_if)
414 return Reason_intrinsic;
415 else if (reason == Reason_unstable_fused_if)
416 return Reason_range_check;
417 else
418 return Reason_none;
419 }
420
421 static bool reason_is_speculate(int reason) {
422 if (reason == Reason_speculate_class_check ||
423 reason == Reason_speculate_null_check ||
424 reason == Reason_speculate_null_assert) {
425 return true;
426 }
427 return false;
428 }
429
430 static DeoptReason reason_null_check(bool speculative) {
431 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
432 }
433
434 static DeoptReason reason_class_check(bool speculative) {
435 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
436 }
437
438 static DeoptReason reason_null_assert(bool speculative) {
439 return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert;
440 }
441
442 static uint per_method_trap_limit(int reason) {
443 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
444 }
445
446 static const char* trap_reason_name(int reason);
447 static const char* trap_action_name(int action);
448 // Format like reason='foo' action='bar' index='123'.
449 // This is suitable both for XML and for tty output.
450 static const char* format_trap_request(char* buf, size_t buflen,
451 int trap_request);
452
453 static jint total_deoptimization_count();
454 static jint deoptimization_count(const char* reason_str, const char* action_str);
455
456 // JVMTI PopFrame support
457
458 // Preserves incoming arguments to the popped frame when it is
459 // returning to a deoptimized caller
460 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
461
462 static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing);
463 private:
464 // Update the mdo's count and per-BCI reason bits, returning previous state:
465 static ProfileData* query_update_method_data(MethodData* trap_mdo,
466 int trap_bci,
467 DeoptReason reason,
468 bool update_total_trap_count,
469 #if INCLUDE_JVMCI
470 bool is_osr,
471 #endif
472 Method* compiled_method,
473 //outputs:
474 uint& ret_this_trap_count,
475 bool& ret_maybe_prior_trap,
476 bool& ret_maybe_prior_recompile);
477 // class loading support for uncommon trap
478 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
479
480 static UnrollBlock* fetch_unroll_info_helper(JavaThread* current, int exec_mode);
481
482 static DeoptAction _unloaded_action; // == Action_reinterpret;
483 static const char* _trap_reason_name[];
484 static const char* _trap_action_name[];
485
486 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
487 // Note: Histogram array size is 1-2 Kb.
488
489 public:
490 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
491 };
492
493 #endif // SHARE_RUNTIME_DEOPTIMIZATION_HPP