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