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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 void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
155 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
156 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal);
157 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures);
158 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
159 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);)
160 #endif // COMPILER2 || INCLUDE_JVMCI
161
162 public:
163 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
164
165 // Interface used for unpacking deoptimized frames
166
167 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
168 // This is only a CheapObj to ease debugging after a deopt failure
169 class UnrollBlock : public CHeapObj<mtCompiler> {
170 friend class VMStructs;
171 friend class JVMCIVMStructs;
172 private:
173 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
174 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
175 int _number_of_frames; // Number frames to unroll
176 int _total_frame_sizes; // Total of number*sizes frames
177 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
178 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
179 intptr_t* _register_block; // Block for storing callee-saved registers.
180 BasicType _return_type; // Tells if we have to restore double or long return value
181 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
182 int _caller_actual_parameters; // The number of actual arguments at the
183 // interpreted caller of the deoptimized frame
184 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info
185
186 // The following fields are used as temps during the unpacking phase
187 // (which is tight on registers, especially on x86). They really ought
188 // to be PD variables but that involves moving this class into its own
189 // file to use the pd include mechanism. Maybe in a later cleanup ...
190 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
191 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
192 public:
193 // Constructor
194 UnrollBlock(int size_of_deoptimized_frame,
195 int caller_adjustment,
196 int caller_actual_parameters,
197 int number_of_frames,
198 intptr_t* frame_sizes,
199 address* frames_pcs,
200 BasicType return_type,
201 int unpack_kind);
202 ~UnrollBlock();
203
204 // Returns where a register is located.
205 intptr_t* value_addr_at(int register_number) const;
206
207 // Accessors
208 intptr_t* frame_sizes() const { return _frame_sizes; }
209 int number_of_frames() const { return _number_of_frames; }
210 address* frame_pcs() const { return _frame_pcs ; }
211 int unpack_kind() const { return _unpack_kind; }
212
213 // Returns the total size of frames
214 int size_of_frames() const;
215
216 void set_initial_info(intptr_t info) { _initial_info = info; }
217
218 int caller_actual_parameters() const { return _caller_actual_parameters; }
219
220 // Accessors used by the code generator for the unpack stub.
221 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
222 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
223 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
224 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
225 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
226 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
227 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
228 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
229 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
230 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
231 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
232 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
233
234 BasicType return_type() const { return _return_type; }
235 void print();
236 };
237
238 //** Returns an UnrollBlock continuing information
239 // how to make room for the resulting interpreter frames.
240 // Called by assembly stub after execution has returned to
241 // deoptimized frame.
242 // @argument thread. Thread where stub_frame resides.
243 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
244 static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode);
245
246 //** Unpacks vframeArray onto execution stack
247 // Called by assembly stub after execution has returned to
248 // deoptimized frame and after the stack unrolling.
249 // @argument thread. Thread where stub_frame resides.
250 // @argument exec_mode. Determines how execution should be continued in top frame.
251 // 0 means continue after current byte code
252 // 1 means exception has happened, handle exception
253 // 2 means reexecute current bytecode (for uncommon traps).
254 // @see OptoRuntime::deoptimization_unpack_frames_C
255 // Return BasicType of call return type, if any
256 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
257
258 // Cleans up deoptimization bits on thread after unpacking or in the
259 // case of an exception.
260 static void cleanup_deopt_info(JavaThread *thread,
261 vframeArray * array);
262
263 // Restores callee saved values from deoptimized frame into oldest interpreter frame
264 // so caller of the deoptimized frame will get back the values it expects.
265 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
266
267 //** Performs an uncommon trap for compiled code.
268 // The top most compiler frame is converted into interpreter frames
269 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode);
270 // Helper routine that enters the VM and may block
271 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
272
273 //** Deoptimizes the frame identified by id.
274 // Only called from VMDeoptimizeFrame
275 // @argument thread. Thread where stub_frame resides.
276 // @argument id. id of frame that should be deoptimized.
277 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
278
279 // if thread is not the current thread then execute
280 // VM_DeoptimizeFrame otherwise deoptimize directly.
281 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
282 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
283
284 // Statistics
285 static void gather_statistics(DeoptReason reason, DeoptAction action,
286 Bytecodes::Code bc = Bytecodes::_illegal);
287 static void print_statistics();
288
289 // How much room to adjust the last frame's SP by, to make space for
290 // the callee's interpreter frame (which expects locals to be next to
291 // incoming arguments)
292 static int last_frame_adjust(int callee_parameters, int callee_locals);
293
294 // trap_request codes
295 static DeoptReason trap_request_reason(int trap_request) {
296 if (trap_request < 0)
297 return (DeoptReason)
298 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
299 else
300 // standard reason for unloaded CP entry
301 return Reason_unloaded;
302 }
303 static DeoptAction trap_request_action(int trap_request) {
304 if (trap_request < 0)
305 return (DeoptAction)
306 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
307 else
308 // standard action for unloaded CP entry
309 return _unloaded_action;
310 }
311 static int trap_request_debug_id(int trap_request) {
312 if (trap_request < 0) {
313 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits));
314 } else {
315 // standard action for unloaded CP entry
316 return 0;
317 }
318 }
319 static int trap_request_index(int trap_request) {
320 if (trap_request < 0)
321 return -1;
322 else
323 return trap_request;
324 }
325 static int make_trap_request(DeoptReason reason, DeoptAction action,
326 int index = -1) {
327 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
328 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
329 int trap_request;
330 if (index != -1)
331 trap_request = index;
332 else
333 trap_request = (~(((reason) << _reason_shift)
334 + ((action) << _action_shift)));
335 assert(reason == trap_request_reason(trap_request), "valid reason");
336 assert(action == trap_request_action(trap_request), "valid action");
337 assert(index == trap_request_index(trap_request), "valid index");
338 return trap_request;
339 }
340
341 // The trap_state stored in a MDO is decoded here.
342 // It records two items of information.
343 // reason: If a deoptimization happened here, what its reason was,
344 // or if there were multiple deopts with differing reasons.
345 // recompiled: If a deoptimization here triggered a recompilation.
346 // Note that not all reasons are recorded per-bci.
347 static DeoptReason trap_state_reason(int trap_state);
348 static int trap_state_has_reason(int trap_state, int reason);
349 static int trap_state_add_reason(int trap_state, int reason);
350 static bool trap_state_is_recompiled(int trap_state);
351 static int trap_state_set_recompiled(int trap_state, bool z);
352 static const char* format_trap_state(char* buf, size_t buflen,
353 int trap_state);
354
355 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
356 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
357 }
358
359 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
360 if (reason_is_recorded_per_bytecode(reason))
361 return reason;
362 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
363 return Reason_null_check; // recorded per BCI as a null check
364 else if (reason == Reason_speculate_class_check)
365 return Reason_class_check;
366 else if (reason == Reason_speculate_null_check)
367 return Reason_null_check;
368 else if (reason == Reason_unstable_if)
369 return Reason_intrinsic;
370 else if (reason == Reason_unstable_fused_if)
371 return Reason_range_check;
372 else
373 return Reason_none;
374 }
375
376 static bool reason_is_speculate(int reason) {
377 if (reason == Reason_speculate_class_check || reason == Reason_speculate_null_check) {
378 return true;
379 }
380 return false;
381 }
382
383 static DeoptReason reason_null_check(bool speculative) {
384 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
385 }
386
387 static DeoptReason reason_class_check(bool speculative) {
388 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
389 }
390
391 static uint per_method_trap_limit(int reason) {
392 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
393 }
394
395 static const char* trap_reason_name(int reason);
396 static const char* trap_action_name(int action);
397 // Format like reason='foo' action='bar' index='123'.
398 // This is suitable both for XML and for tty output.
399 static const char* format_trap_request(char* buf, size_t buflen,
400 int trap_request);
401
402 static jint total_deoptimization_count();
403 static jint deoptimization_count(DeoptReason reason);
404
405 // JVMTI PopFrame support
406
407 // Preserves incoming arguments to the popped frame when it is
408 // returning to a deoptimized caller
409 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
410
411 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
412 private:
413 // Update the mdo's count and per-BCI reason bits, returning previous state:
414 static ProfileData* query_update_method_data(MethodData* trap_mdo,
415 int trap_bci,
416 DeoptReason reason,
417 bool update_total_trap_count,
418 #if INCLUDE_JVMCI
419 bool is_osr,
420 #endif
421 Method* compiled_method,
422 //outputs:
423 uint& ret_this_trap_count,
424 bool& ret_maybe_prior_trap,
425 bool& ret_maybe_prior_recompile);
426 // class loading support for uncommon trap
427 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
428 static void load_class_by_index(const constantPoolHandle& constant_pool, int index);
429
430 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode);
431
432 static DeoptAction _unloaded_action; // == Action_reinterpret;
433 static const char* _trap_reason_name[];
434 static const char* _trap_action_name[];
435
436 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
437 // Note: Histogram array size is 1-2 Kb.
438
439 public:
440 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
441 };
442
443 class DeoptimizationMarker : StackObj { // for profiling
444 static bool _is_active;
445 public:
446 DeoptimizationMarker() { _is_active = true; }
447 ~DeoptimizationMarker() { _is_active = false; }
448 static bool is_active() { return _is_active; }
449 };
450
451 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP