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