1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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 Reason_null_check, // saw unexpected null or zero divisor (@bci)
46 Reason_null_assert, // saw unexpected non-null or non-zero (@bci)
47 Reason_range_check, // saw unexpected array index (@bci)
48 Reason_class_check, // saw unexpected object class (@bci)
49 Reason_array_check, // saw unexpected array class (aastore @bci)
50 Reason_intrinsic, // saw unexpected operand to intrinsic (@bci)
51 Reason_bimorphic, // saw unexpected object class in bimorphic inlining (@bci)
52
53 Reason_unloaded, // unloaded class or constant pool entry
54 Reason_uninitialized, // bad class state (uninitialized)
55 Reason_unreached, // code is not reached, compiler
56 Reason_unhandled, // arbitrary compiler limitation
57 Reason_constraint, // arbitrary runtime constraint violated
58 Reason_div0_check, // a null_check due to division by zero
59 Reason_age, // nmethod too old; tier threshold reached
60 Reason_predicate, // compiler generated predicate failed
61 Reason_loop_limit_check, // compiler generated loop limits check failed
62 Reason_speculate_class_check, // saw unexpected object class from type speculation
63 Reason_speculate_null_check, // saw unexpected null from type speculation
64 Reason_rtm_state_change, // rtm state change detected
65 Reason_tenured, // age of the code has reached the limit
66 Reason_LIMIT,
67 // Note: Keep this enum in sync. with _trap_reason_name.
68 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc
69 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of
70 // DataLayout::trap_bits. This dependency is enforced indirectly
71 // via asserts, to avoid excessive direct header-to-header dependencies.
72 // See Deoptimization::trap_state_reason and class DataLayout.
73 };
74
75 // What action must be taken by the runtime?
76 enum DeoptAction {
77 Action_none, // just interpret, do not invalidate nmethod
78 Action_maybe_recompile, // recompile the nmethod; need not invalidate
79 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile
80 Action_make_not_entrant, // invalidate the nmethod, recompile (probably)
81 Action_make_not_compilable, // invalidate the nmethod and do not compile
82 Action_LIMIT
83 // Note: Keep this enum in sync. with _trap_action_name.
84 };
85
86 enum {
87 _action_bits = 3,
88 _reason_bits = 5,
89 _action_shift = 0,
90 _reason_shift = _action_shift+_action_bits,
91 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist
92 };
93
94 enum UnpackType {
95 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack
96 Unpack_exception = 1, // exception is pending
97 Unpack_uncommon_trap = 2, // redo last byte code (C2 only)
98 Unpack_reexecute = 3 // reexecute bytecode (C1 only)
99 };
100
101 // Checks all compiled methods. Invalid methods are deleted and
102 // corresponding activations are deoptimized.
103 static int deoptimize_dependents();
104
105 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame
106 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map);
107
108 private:
109 // Does the actual work for deoptimizing a single frame
110 static void deoptimize_single_frame(JavaThread* thread, frame fr);
111
112 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking
113 // is enabled
114 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map);
115 // Helper function to revoke biases of all monitors in frames
116 // executing in a particular CodeBlob if UseBiasedLocking is enabled
117 static void revoke_biases_of_monitors(CodeBlob* cb);
118
119 #ifdef COMPILER2
120 // Support for restoring non-escaping objects
121 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS);
122 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type);
123 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj);
124 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects);
125 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread);
126 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects);)
127 #endif // COMPILER2
128
129 public:
130 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk);
131
132 // Interface used for unpacking deoptimized frames
133
134 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob).
135 // This is only a CheapObj to ease debugging after a deopt failure
136 class UnrollBlock : public CHeapObj<mtCompiler> {
137 private:
138 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame
139 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame
140 int _number_of_frames; // Number frames to unroll
141 int _total_frame_sizes; // Total of number*sizes frames
142 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack
143 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack
144 intptr_t* _register_block; // Block for storing callee-saved registers.
145 BasicType _return_type; // Tells if we have to restore double or long return value
146 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86)
147 int _caller_actual_parameters; // The number of actual arguments at the
148 // interpreted caller of the deoptimized frame
149
150 // The following fields are used as temps during the unpacking phase
151 // (which is tight on registers, especially on x86). They really ought
152 // to be PD variables but that involves moving this class into its own
153 // file to use the pd include mechanism. Maybe in a later cleanup ...
154 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp)
155 intptr_t _unpack_kind; // SHOULD BE PD VARIABLE (x86 unpack kind)
156 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp)
157 public:
158 // Constructor
159 UnrollBlock(int size_of_deoptimized_frame,
160 int caller_adjustment,
161 int caller_actual_parameters,
162 int number_of_frames,
163 intptr_t* frame_sizes,
164 address* frames_pcs,
165 BasicType return_type);
166 ~UnrollBlock();
167
168 // Returns where a register is located.
169 intptr_t* value_addr_at(int register_number) const;
170
171 // Accessors
172 intptr_t* frame_sizes() const { return _frame_sizes; }
173 int number_of_frames() const { return _number_of_frames; }
174 address* frame_pcs() const { return _frame_pcs ; }
175
176 // Returns the total size of frames
177 int size_of_frames() const;
178
179 void set_initial_info(intptr_t info) { _initial_info = info; }
180
181 int caller_actual_parameters() const { return _caller_actual_parameters; }
182
183 // Accessors used by the code generator for the unpack stub.
184 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); }
185 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); }
186 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); }
187 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); }
188 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); }
189 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); }
190 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); }
191 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); }
192 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); }
193 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); }
194 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); }
195 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); }
196
197 BasicType return_type() const { return _return_type; }
198 void print();
199 };
200
201 //** Returns an UnrollBlock continuing information
202 // how to make room for the resulting interpreter frames.
203 // Called by assembly stub after execution has returned to
204 // deoptimized frame.
205 // @argument thread. Thread where stub_frame resides.
206 // @see OptoRuntime::deoptimization_fetch_unroll_info_C
207 static UnrollBlock* fetch_unroll_info(JavaThread* thread);
208
209 //** Unpacks vframeArray onto execution stack
210 // Called by assembly stub after execution has returned to
211 // deoptimized frame and after the stack unrolling.
212 // @argument thread. Thread where stub_frame resides.
213 // @argument exec_mode. Determines how execution should be continued in top frame.
214 // 0 means continue after current byte code
215 // 1 means exception has happened, handle exception
216 // 2 means reexecute current bytecode (for uncommon traps).
217 // @see OptoRuntime::deoptimization_unpack_frames_C
218 // Return BasicType of call return type, if any
219 static BasicType unpack_frames(JavaThread* thread, int exec_mode);
220
221 // Cleans up deoptimization bits on thread after unpacking or in the
222 // case of an exception.
223 static void cleanup_deopt_info(JavaThread *thread,
224 vframeArray * array);
225
226 // Restores callee saved values from deoptimized frame into oldest interpreter frame
227 // so caller of the deoptimized frame will get back the values it expects.
228 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array);
229
230 //** Performs an uncommon trap for compiled code.
231 // The top most compiler frame is converted into interpreter frames
232 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index);
233 // Helper routine that enters the VM and may block
234 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index);
235
236 //** Deoptimizes the frame identified by id.
237 // Only called from VMDeoptimizeFrame
238 // @argument thread. Thread where stub_frame resides.
239 // @argument id. id of frame that should be deoptimized.
240 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id);
241
242 // If thread is not the current thread then execute
243 // VM_DeoptimizeFrame otherwise deoptimize directly.
244 static void deoptimize_frame(JavaThread* thread, intptr_t* id);
245
246 // Statistics
247 static void gather_statistics(DeoptReason reason, DeoptAction action,
248 Bytecodes::Code bc = Bytecodes::_illegal);
249 static void print_statistics();
250
251 // How much room to adjust the last frame's SP by, to make space for
252 // the callee's interpreter frame (which expects locals to be next to
253 // incoming arguments)
254 static int last_frame_adjust(int callee_parameters, int callee_locals);
255
256 // trap_request codes
257 static DeoptReason trap_request_reason(int trap_request) {
258 if (trap_request < 0)
259 return (DeoptReason)
260 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits));
261 else
262 // standard reason for unloaded CP entry
263 return Reason_unloaded;
264 }
265 static DeoptAction trap_request_action(int trap_request) {
266 if (trap_request < 0)
267 return (DeoptAction)
268 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits));
269 else
270 // standard action for unloaded CP entry
271 return _unloaded_action;
272 }
273 static int trap_request_index(int trap_request) {
274 if (trap_request < 0)
275 return -1;
276 else
277 return trap_request;
278 }
279 static int make_trap_request(DeoptReason reason, DeoptAction action,
280 int index = -1) {
281 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits");
282 assert((1 << _action_bits) >= Action_LIMIT, "enough bits");
283 int trap_request;
284 if (index != -1)
285 trap_request = index;
286 else
287 trap_request = (~(((reason) << _reason_shift)
288 + ((action) << _action_shift)));
289 assert(reason == trap_request_reason(trap_request), "valid reason");
290 assert(action == trap_request_action(trap_request), "valid action");
291 assert(index == trap_request_index(trap_request), "valid index");
292 return trap_request;
293 }
294
295 // The trap_state stored in a MDO is decoded here.
296 // It records two items of information.
297 // reason: If a deoptimization happened here, what its reason was,
298 // or if there were multiple deopts with differing reasons.
299 // recompiled: If a deoptimization here triggered a recompilation.
300 // Note that not all reasons are recorded per-bci.
301 static DeoptReason trap_state_reason(int trap_state);
302 static int trap_state_has_reason(int trap_state, int reason);
303 static int trap_state_add_reason(int trap_state, int reason);
304 static bool trap_state_is_recompiled(int trap_state);
305 static int trap_state_set_recompiled(int trap_state, bool z);
306 static const char* format_trap_state(char* buf, size_t buflen,
307 int trap_state);
308
309 static bool reason_is_recorded_per_bytecode(DeoptReason reason) {
310 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT;
311 }
312
313 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) {
314 if (reason_is_recorded_per_bytecode(reason))
315 return reason;
316 else if (reason == Reason_div0_check) // null check due to divide-by-zero?
317 return Reason_null_check; // recorded per BCI as a null check
318 else if (reason == Reason_speculate_class_check)
319 return Reason_class_check;
320 else if (reason == Reason_speculate_null_check)
321 return Reason_null_check;
322 else
323 return Reason_none;
324 }
325
326 static bool reason_is_speculate(int reason) {
327 if (reason == Reason_speculate_class_check || reason == Reason_speculate_null_check) {
328 return true;
329 }
330 return false;
331 }
332
333 static DeoptReason reason_null_check(bool speculative) {
334 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check;
335 }
336
337 static DeoptReason reason_class_check(bool speculative) {
338 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check;
339 }
340
341 static uint per_method_trap_limit(int reason) {
342 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit;
343 }
344
345 static const char* trap_reason_name(int reason);
346 static const char* trap_action_name(int action);
347 // Format like reason='foo' action='bar' index='123'.
348 // This is suitable both for XML and for tty output.
349 static const char* format_trap_request(char* buf, size_t buflen,
350 int trap_request);
351
352 static jint total_deoptimization_count();
353 static jint deoptimization_count(DeoptReason reason);
354
355 // JVMTI PopFrame support
356
357 // Preserves incoming arguments to the popped frame when it is
358 // returning to a deoptimized caller
359 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address);
360
361 static MethodData* get_method_data(JavaThread* thread, methodHandle m, bool create_if_missing);
362 private:
363 // Update the mdo's count and per-BCI reason bits, returning previous state:
364 static ProfileData* query_update_method_data(MethodData* trap_mdo,
365 int trap_bci,
366 DeoptReason reason,
367 Method* compiled_method,
368 //outputs:
369 uint& ret_this_trap_count,
370 bool& ret_maybe_prior_trap,
371 bool& ret_maybe_prior_recompile);
372 // class loading support for uncommon trap
373 static void load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS);
374 static void load_class_by_index(constantPoolHandle constant_pool, int index);
375
376 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread);
377
378 static DeoptAction _unloaded_action; // == Action_reinterpret;
379 static const char* _trap_reason_name[];
380 static const char* _trap_action_name[];
381
382 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT];
383 // Note: Histogram array size is 1-2 Kb.
384
385 public:
386 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason);
387 };
388
389 class DeoptimizationMarker : StackObj { // for profiling
390 static bool _is_active;
391 public:
392 DeoptimizationMarker() { _is_active = true; }
393 ~DeoptimizationMarker() { _is_active = false; }
394 static bool is_active() { return _is_active; }
395 };
396
397 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP