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.inline.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 7 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 // recorded per method
66 Reason_unloaded, // unloaded class or constant pool entry
67 Reason_uninitialized, // bad class state (uninitialized)
68 Reason_unreached, // code is not reached, compiler
69 Reason_unhandled, // arbitrary compiler limitation
70 Reason_constraint, // arbitrary runtime constraint violated
71 Reason_div0_check, // a null_check due to division by zero
72 Reason_age, // nmethod too old; tier threshold reached
73 Reason_predicate, // compiler generated predicate failed
74 Reason_loop_limit_check, // compiler generated loop limits check failed
75 Reason_speculate_class_check, // saw unexpected object class from type speculation
76 Reason_speculate_null_check, // saw unexpected null from type speculation
77 Reason_rtm_state_change, // rtm state change detected
78 Reason_unstable_if, // a branch predicted always false was taken
79 Reason_unstable_fused_if, // fused two ifs that had each one untaken branch. One is now taken.
80 #if INCLUDE_JVMCI
81 Reason_aliasing, // optimistic assumption about aliasing failed
82 Reason_transfer_to_interpreter, // explicit transferToInterpreter()
83 Reason_not_compiled_exception_handler,
84 Reason_unresolved,
85 Reason_jsr_mismatch,
86 #endif
87
88 // Reason_tenured is counted separately, add normal counted Reasons above.
89 // Related to MethodData::_trap_hist_limit where Reason_tenured isn't included
90 Reason_tenured, // age of the code has reached the limit
91 Reason_LIMIT,
92
93 // Note: Keep this enum in sync. with _trap_reason_name.
94 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc
95 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
96 // DataLayout::trap_bits. This dependency is enforced indirectly
97 // via asserts, to avoid excessive direct header-to-header dependencies.
98 // See Deoptimization::trap_state_reason and class DataLayout.
99 };
100
101 // What action must be taken by the runtime?
102 enum DeoptAction {
103 Action_none, // just interpret, do not invalidate nmethod
104 Action_maybe_recompile, // recompile the nmethod; need not invalidate
105 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
106 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
107 Action_make_not_compilable, // invalidate the nmethod and do not compile
108 Action_LIMIT
109 // Note: Keep this enum in sync. with _trap_action_name.
110 };
111
112 enum {
113 _action_bits = 3,
114 _reason_bits = 5,
115 _debug_id_bits = 23,
116 _action_shift = 0,
117 _reason_shift = _action_shift+_action_bits,
118 _debug_id_shift = _reason_shift+_reason_bits,
119 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
120 };
121
122 enum UnpackType {
123 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
124 Unpack_exception = 1, // exception is pending
125 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
126 Unpack_reexecute = 3, // reexecute bytecode (C1 only)
127 Unpack_LIMIT = 4
128 };
129
130 // Checks all compiled methods. Invalid methods are deleted and
131 // corresponding activations are deoptimized.
132 static int deoptimize_dependents();
133
134 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
135 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
136 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map, DeoptReason reason);
137
138 private:
139 // Does the actual work for deoptimizing a single frame
140 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason);
141
142 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
143 // is enabled
144 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
145 // Helper function to revoke biases of all monitors in frames
146 // executing in a particular CodeBlob if UseBiasedLocking is enabled
147 static void revoke_biases_of_monitors(CodeBlob* cb);
148
149 #if defined(COMPILER2) || INCLUDE_JVMCI
150 JVMCI_ONLY(public:)
151
152 // Support for restoring non-escaping objects
153 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
154 static bool realloc_value_type_result(ValueKlass* vk, const RegisterMap& map, GrowableArray<Handle>& return_oops, TRAPS);
155 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
156 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
157 static void reassign_value_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, valueArrayOop obj, ValueArrayKlass* vak, TRAPS);
158 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal, TRAPS);
159 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures);
160 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
161 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);)
162 #endif // COMPILER2 || INCLUDE_JVMCI
163
164 public:
165 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
166
167 // Interface used for unpacking deoptimized frames
168
169 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
170 // This is only a CheapObj to ease debugging after a deopt failure
171 class UnrollBlock : public CHeapObj<mtCompiler> {
172 friend class VMStructs;
173 friend class JVMCIVMStructs;
174 private:
175 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
176 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
177 int _number_of_frames; // Number frames to unroll
178 int _total_frame_sizes; // Total of number*sizes frames
179 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
180 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
181 intptr_t* _register_block; // Block for storing callee-saved registers.
182 BasicType _return_type; // Tells if we have to restore double or long return value
183 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
184 int _caller_actual_parameters; // The number of actual arguments at the
185 // interpreted caller of the deoptimized frame
186 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info
187
188 // The following fields are used as temps during the unpacking phase
189 // (which is tight on registers, especially on x86). They really ought
190 // to be PD variables but that involves moving this class into its own
191 // file to use the pd include mechanism. Maybe in a later cleanup ...
192 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
193 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
194 public:
195 // Constructor
196 UnrollBlock(int size_of_deoptimized_frame,
197 int caller_adjustment,
198 int caller_actual_parameters,
199 int number_of_frames,
200 intptr_t* frame_sizes,
201 address* frames_pcs,
202 BasicType return_type,
203 int unpack_kind);
204 ~UnrollBlock();
205
206 // Returns where a register is located.
207 intptr_t* value_addr_at(int register_number) const;
208
209 // Accessors
210 intptr_t* frame_sizes() const { return _frame_sizes; }
211 int number_of_frames() const { return _number_of_frames; }
212 address* frame_pcs() const { return _frame_pcs ; }
213 int unpack_kind() const { return _unpack_kind; }
214
215 // Returns the total size of frames
216 int size_of_frames() const;
217
218 void set_initial_info(intptr_t info) { _initial_info = info; }
219
220 int caller_actual_parameters() const { return _caller_actual_parameters; }
221
222 // Accessors used by the code generator for the unpack stub.
223 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
224 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
225 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
226 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
227 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
228 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
229 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
230 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
231 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
232 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
233 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
234 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
235
236 BasicType return_type() const { return _return_type; }
237 void print();
238 };
239
240 //** Returns an UnrollBlock continuing information
241 // how to make room for the resulting interpreter frames.
242 // Called by assembly stub after execution has returned to
243 // deoptimized frame.
244 // @argument thread. Thread where stub_frame resides.
245 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
246 static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode);
247
248 //** Unpacks vframeArray onto execution stack
249 // Called by assembly stub after execution has returned to
250 // deoptimized frame and after the stack unrolling.
251 // @argument thread. Thread where stub_frame resides.
252 // @argument exec_mode. Determines how execution should be continued in top frame.
253 // 0 means continue after current byte code
254 // 1 means exception has happened, handle exception
255 // 2 means reexecute current bytecode (for uncommon traps).
256 // @see OptoRuntime::deoptimization_unpack_frames_C
257 // Return BasicType of call return type, if any
258 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
259
260 // Cleans up deoptimization bits on thread after unpacking or in the
261 // case of an exception.
262 static void cleanup_deopt_info(JavaThread *thread,
263 vframeArray * array);
264
265 // Restores callee saved values from deoptimized frame into oldest interpreter frame
266 // so caller of the deoptimized frame will get back the values it expects.
267 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
268
269 //** Performs an uncommon trap for compiled code.
270 // The top most compiler frame is converted into interpreter frames
271 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode);
272 // Helper routine that enters the VM and may block
273 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
274
275 //** Deoptimizes the frame identified by id.
276 // Only called from VMDeoptimizeFrame
277 // @argument thread. Thread where stub_frame resides.
278 // @argument id. id of frame that should be deoptimized.
279 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
280
281 // if thread is not the current thread then execute
282 // VM_DeoptimizeFrame otherwise deoptimize directly.
283 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
284 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
285
286 // Statistics
287 static void gather_statistics(DeoptReason reason, DeoptAction action,
288 Bytecodes::Code bc = Bytecodes::_illegal);
289 static void print_statistics();
290
291 // How much room to adjust the last frame's SP by, to make space for
292 // the callee's interpreter frame (which expects locals to be next to
293 // incoming arguments)
294 static int last_frame_adjust(int callee_parameters, int callee_locals);
295
296 // trap_request codes
297 static DeoptReason trap_request_reason(int trap_request) {
298 if (trap_request < 0)
299 return (DeoptReason)
300 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
301 else
302 // standard reason for unloaded CP entry
303 return Reason_unloaded;
304 }
305 static DeoptAction trap_request_action(int trap_request) {
306 if (trap_request < 0)
307 return (DeoptAction)
308 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
309 else
310 // standard action for unloaded CP entry
311 return _unloaded_action;
312 }
313 static int trap_request_debug_id(int trap_request) {
314 if (trap_request < 0) {
315 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits));
316 } else {
317 // standard action for unloaded CP entry
318 return 0;
319 }
320 }
321 static int trap_request_index(int trap_request) {
322 if (trap_request < 0)
323 return -1;
324 else
325 return trap_request;
326 }
327 static int make_trap_request(DeoptReason reason, DeoptAction action,
328 int index = -1) {
329 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
330 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
331 int trap_request;
332 if (index != -1)
333 trap_request = index;
334 else
335 trap_request = (~(((reason) << _reason_shift)
336 + ((action) << _action_shift)));
337 assert(reason == trap_request_reason(trap_request), "valid reason");
338 assert(action == trap_request_action(trap_request), "valid action");
339 assert(index == trap_request_index(trap_request), "valid index");
340 return trap_request;
341 }
342
343 // The trap_state stored in a MDO is decoded here.
344 // It records two items of information.
345 // reason: If a deoptimization happened here, what its reason was,
346 // or if there were multiple deopts with differing reasons.
347 // recompiled: If a deoptimization here triggered a recompilation.
348 // Note that not all reasons are recorded per-bci.
349 static DeoptReason trap_state_reason(int trap_state);
350 static int trap_state_has_reason(int trap_state, int reason);
351 static int trap_state_add_reason(int trap_state, int reason);
352 static bool trap_state_is_recompiled(int trap_state);
353 static int trap_state_set_recompiled(int trap_state, bool z);
354 static const char* format_trap_state(char* buf, size_t buflen,
355 int trap_state);
356
357 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
358 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
359 }
360
361 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
362 if (reason_is_recorded_per_bytecode(reason))
363 return reason;
364 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
365 return Reason_null_check; // recorded per BCI as a null check
366 else if (reason == Reason_speculate_class_check)
367 return Reason_class_check;
368 else if (reason == Reason_speculate_null_check)
369 return Reason_null_check;
370 else if (reason == Reason_unstable_if)
371 return Reason_intrinsic;
372 else if (reason == Reason_unstable_fused_if)
373 return Reason_range_check;
374 else
375 return Reason_none;
376 }
377
378 static bool reason_is_speculate(int reason) {
379 if (reason == Reason_speculate_class_check || reason == Reason_speculate_null_check) {
380 return true;
381 }
382 return false;
383 }
384
385 static DeoptReason reason_null_check(bool speculative) {
386 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
387 }
388
389 static DeoptReason reason_class_check(bool speculative) {
390 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
391 }
392
393 static uint per_method_trap_limit(int reason) {
394 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
395 }
396
397 static const char* trap_reason_name(int reason);
398 static const char* trap_action_name(int action);
399 // Format like reason='foo' action='bar' index='123'.
400 // This is suitable both for XML and for tty output.
401 static const char* format_trap_request(char* buf, size_t buflen,
402 int trap_request);
403
404 static jint total_deoptimization_count();
405 static jint deoptimization_count(DeoptReason reason);
406
407 // JVMTI PopFrame support
408
409 // Preserves incoming arguments to the popped frame when it is
410 // returning to a deoptimized caller
411 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
412
413 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
414 private:
415 // Update the mdo's count and per-BCI reason bits, returning previous state:
416 static ProfileData* query_update_method_data(MethodData* trap_mdo,
417 int trap_bci,
418 DeoptReason reason,
419 bool update_total_trap_count,
420 #if INCLUDE_JVMCI
421 bool is_osr,
422 #endif
423 Method* compiled_method,
424 //outputs:
425 uint& ret_this_trap_count,
426 bool& ret_maybe_prior_trap,
427 bool& ret_maybe_prior_recompile);
428 // class loading support for uncommon trap
429 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
430 static void load_class_by_index(const constantPoolHandle& constant_pool, int index);
431
432 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode);
433
434 static DeoptAction _unloaded_action; // == Action_reinterpret;
435 static const char* _trap_reason_name[];
436 static const char* _trap_action_name[];
437
438 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
439 // Note: Histogram array size is 1-2 Kb.
440
441 public:
442 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
443 };
444
445 class DeoptimizationMarker : StackObj { // for profiling
446 static bool _is_active;
447 public:
448 DeoptimizationMarker() { _is_active = true; }
449 ~DeoptimizationMarker() { _is_active = false; }
450 static bool is_active() { return _is_active; }
451 };
452
453 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP