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