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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 #if INCLUDE_JVMCI
141 // Can reconstruct virtualized unsafe large accesses to byte arrays.
142 static const int _support_large_access_byte_array_virtualization = 1;
143 #endif
144
145 // Make all nmethods that are marked_for_deoptimization not_entrant and deoptimize any live
146 // activations using those nmethods. If an nmethod is passed as an argument then it is
147 // marked_for_deoptimization and made not_entrant. Otherwise a scan of the code cache is done to
148 // find all marked nmethods and they are made not_entrant.
149 static void deoptimize_all_marked(nmethod* nmethod_only = NULL);
150
151 private:
152 // Revoke biased locks at deopt.
153 static void revoke_from_deopt_handler(JavaThread* thread, frame fr, RegisterMap* map);
154
155 public:
156 // Deoptimizes a frame lazily. Deopt happens on return to the frame.
157 static void deoptimize(JavaThread* thread, frame fr, DeoptReason reason = Reason_constraint);
158
159 #if INCLUDE_JVMCI
160 static address deoptimize_for_missing_exception_handler(CompiledMethod* cm);
161 static oop get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, TRAPS);
162 #endif
163
164 private:
165 // Does the actual work for deoptimizing a single frame
166 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason);
167
168 #if COMPILER2_OR_JVMCI
169 public:
170
171 // Support for restoring non-escaping objects
172 static bool realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS);
173 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
174 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
175 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal);
176 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures);
177 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array);
178 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);)
179 #endif // COMPILER2_OR_JVMCI
180
181 public:
182 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures);
183
184 // Interface used for unpacking deoptimized frames
185
186 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
187 // This is only a CheapObj to ease debugging after a deopt failure
188 class UnrollBlock : public CHeapObj<mtCompiler> {
189 friend class VMStructs;
190 friend class JVMCIVMStructs;
191 private:
192 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
193 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
194 int _number_of_frames; // Number frames to unroll
195 int _total_frame_sizes; // Total of number*sizes frames
196 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
197 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
198 intptr_t* _register_block; // Block for storing callee-saved registers.
199 BasicType _return_type; // Tells if we have to restore double or long return value
200 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
201 int _caller_actual_parameters; // The number of actual arguments at the
202 // interpreted caller of the deoptimized frame
203 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info
204
205 // The following fields are used as temps during the unpacking phase
206 // (which is tight on registers, especially on x86). They really ought
207 // to be PD variables but that involves moving this class into its own
208 // file to use the pd include mechanism. Maybe in a later cleanup ...
209 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
210 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
211 public:
212 // Constructor
213 UnrollBlock(int size_of_deoptimized_frame,
214 int caller_adjustment,
215 int caller_actual_parameters,
216 int number_of_frames,
217 intptr_t* frame_sizes,
218 address* frames_pcs,
219 BasicType return_type,
220 int unpack_kind);
221 ~UnrollBlock();
222
223 // Returns where a register is located.
224 intptr_t* value_addr_at(int register_number) const;
225
226 // Accessors
227 intptr_t* frame_sizes() const { return _frame_sizes; }
228 int number_of_frames() const { return _number_of_frames; }
229 address* frame_pcs() const { return _frame_pcs ; }
230 int unpack_kind() const { return _unpack_kind; }
231
232 // Returns the total size of frames
233 int size_of_frames() const;
234
235 void set_initial_info(intptr_t info) { _initial_info = info; }
236
237 int caller_actual_parameters() const { return _caller_actual_parameters; }
238
239 // Accessors used by the code generator for the unpack stub.
240 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
241 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
242 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
243 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
244 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
245 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
246 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
247 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
248 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
249 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
250 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
251 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
252
253 BasicType return_type() const { return _return_type; }
254 void print();
255 };
256
257 //** Returns an UnrollBlock continuing information
258 // how to make room for the resulting interpreter frames.
259 // Called by assembly stub after execution has returned to
260 // deoptimized frame.
261 // @argument thread. Thread where stub_frame resides.
262 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
263 static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode);
264
265 //** Unpacks vframeArray onto execution stack
266 // Called by assembly stub after execution has returned to
267 // deoptimized frame and after the stack unrolling.
268 // @argument thread. Thread where stub_frame resides.
269 // @argument exec_mode. Determines how execution should be continued in top frame.
270 // 0 means continue after current byte code
271 // 1 means exception has happened, handle exception
272 // 2 means reexecute current bytecode (for uncommon traps).
273 // @see OptoRuntime::deoptimization_unpack_frames_C
274 // Return BasicType of call return type, if any
275 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
276
277 // Cleans up deoptimization bits on thread after unpacking or in the
278 // case of an exception.
279 static void cleanup_deopt_info(JavaThread *thread,
280 vframeArray * array);
281
282 // Restores callee saved values from deoptimized frame into oldest interpreter frame
283 // so caller of the deoptimized frame will get back the values it expects.
284 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
285
286 //** Performs an uncommon trap for compiled code.
287 // The top most compiler frame is converted into interpreter frames
288 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode);
289 // Helper routine that enters the VM and may block
290 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
291
292 //** Deoptimizes the frame identified by id.
293 // Only called from VMDeoptimizeFrame
294 // @argument thread. Thread where stub_frame resides.
295 // @argument id. id of frame that should be deoptimized.
296 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason);
297
298 // if thread is not the current thread then execute
299 // VM_DeoptimizeFrame otherwise deoptimize directly.
300 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason);
301 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
302
303 // Statistics
304 static void gather_statistics(DeoptReason reason, DeoptAction action,
305 Bytecodes::Code bc = Bytecodes::_illegal);
306 static void print_statistics();
307
308 // How much room to adjust the last frame's SP by, to make space for
309 // the callee's interpreter frame (which expects locals to be next to
310 // incoming arguments)
311 static int last_frame_adjust(int callee_parameters, int callee_locals);
312
313 // trap_request codes
314 static DeoptReason trap_request_reason(int trap_request) {
315 if (trap_request < 0)
316 return (DeoptReason)
317 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
318 else
319 // standard reason for unloaded CP entry
320 return Reason_unloaded;
321 }
322 static DeoptAction trap_request_action(int trap_request) {
323 if (trap_request < 0)
324 return (DeoptAction)
325 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
326 else
327 // standard action for unloaded CP entry
328 return _unloaded_action;
329 }
330 static int trap_request_debug_id(int trap_request) {
331 if (trap_request < 0) {
332 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits));
333 } else {
334 // standard action for unloaded CP entry
335 return 0;
336 }
337 }
338 static int trap_request_index(int trap_request) {
339 if (trap_request < 0)
340 return -1;
341 else
342 return trap_request;
343 }
344 static int make_trap_request(DeoptReason reason, DeoptAction action,
345 int index = -1) {
346 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
347 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
348 int trap_request;
349 if (index != -1)
350 trap_request = index;
351 else
352 trap_request = (~(((reason) << _reason_shift)
353 + ((action) << _action_shift)));
354 assert(reason == trap_request_reason(trap_request), "valid reason");
355 assert(action == trap_request_action(trap_request), "valid action");
356 assert(index == trap_request_index(trap_request), "valid index");
357 return trap_request;
358 }
359
360 // The trap_state stored in a MDO is decoded here.
361 // It records two items of information.
362 // reason: If a deoptimization happened here, what its reason was,
363 // or if there were multiple deopts with differing reasons.
364 // recompiled: If a deoptimization here triggered a recompilation.
365 // Note that not all reasons are recorded per-bci.
366 static DeoptReason trap_state_reason(int trap_state);
367 static int trap_state_has_reason(int trap_state, int reason);
368 static int trap_state_add_reason(int trap_state, int reason);
369 static bool trap_state_is_recompiled(int trap_state);
370 static int trap_state_set_recompiled(int trap_state, bool z);
371 static const char* format_trap_state(char* buf, size_t buflen,
372 int trap_state);
373
374 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
375 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
376 }
377
378 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
379 if (reason_is_recorded_per_bytecode(reason))
380 return reason;
381 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
382 return Reason_null_check; // recorded per BCI as a null check
383 else if (reason == Reason_speculate_class_check)
384 return Reason_class_check;
385 else if (reason == Reason_speculate_null_check)
386 return Reason_null_check;
387 else if (reason == Reason_speculate_null_assert)
388 return Reason_null_assert;
389 else if (reason == Reason_unstable_if)
390 return Reason_intrinsic;
391 else if (reason == Reason_unstable_fused_if)
392 return Reason_range_check;
393 else
394 return Reason_none;
395 }
396
397 static bool reason_is_speculate(int reason) {
398 if (reason == Reason_speculate_class_check ||
399 reason == Reason_speculate_null_check ||
400 reason == Reason_speculate_null_assert) {
401 return true;
402 }
403 return false;
404 }
405
406 static DeoptReason reason_null_check(bool speculative) {
407 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
408 }
409
410 static DeoptReason reason_class_check(bool speculative) {
411 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
412 }
413
414 static DeoptReason reason_null_assert(bool speculative) {
415 return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert;
416 }
417
418 static uint per_method_trap_limit(int reason) {
419 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
420 }
421
422 static const char* trap_reason_name(int reason);
423 static const char* trap_action_name(int action);
424 // Format like reason='foo' action='bar' index='123'.
425 // This is suitable both for XML and for tty output.
426 static const char* format_trap_request(char* buf, size_t buflen,
427 int trap_request);
428
429 static jint total_deoptimization_count();
430
431 // JVMTI PopFrame support
432
433 // Preserves incoming arguments to the popped frame when it is
434 // returning to a deoptimized caller
435 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
436
437 static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing);
438 private:
439 // Update the mdo's count and per-BCI reason bits, returning previous state:
440 static ProfileData* query_update_method_data(MethodData* trap_mdo,
441 int trap_bci,
442 DeoptReason reason,
443 bool update_total_trap_count,
444 #if INCLUDE_JVMCI
445 bool is_osr,
446 #endif
447 Method* compiled_method,
448 //outputs:
449 uint& ret_this_trap_count,
450 bool& ret_maybe_prior_trap,
451 bool& ret_maybe_prior_recompile);
452 // class loading support for uncommon trap
453 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS);
454 static void load_class_by_index(const constantPoolHandle& constant_pool, int index);
455
456 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode);
457
458 static DeoptAction _unloaded_action; // == Action_reinterpret;
459 static const char* _trap_reason_name[];
460 static const char* _trap_action_name[];
461
462 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
463 // Note: Histogram array size is 1-2 Kb.
464
465 public:
466 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
467 };
468
469 class DeoptimizationMarker : StackObj { // for profiling
470 static bool _is_active;
471 public:
472 DeoptimizationMarker() { _is_active = true; }
473 ~DeoptimizationMarker() { _is_active = false; }
474 static bool is_active() { return _is_active; }
475 };
476
477 #endif // SHARE_RUNTIME_DEOPTIMIZATION_HPP