1 /* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 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_speculate_null_assert, // saw unexpected null from type speculation 78 Reason_rtm_state_change, // rtm state change detected 79 Reason_unstable_if, // a branch predicted always false was taken 80 Reason_unstable_fused_if, // fused two ifs that had each one untaken branch. One is now taken. 81 #if INCLUDE_JVMCI 82 Reason_aliasing, // optimistic assumption about aliasing failed 83 Reason_transfer_to_interpreter, // explicit transferToInterpreter() 84 Reason_not_compiled_exception_handler, 85 Reason_unresolved, 86 Reason_jsr_mismatch, 87 #endif 88 89 // Reason_tenured is counted separately, add normal counted Reasons above. 90 // Related to MethodData::_trap_hist_limit where Reason_tenured isn't included 91 Reason_tenured, // age of the code has reached the limit 92 Reason_LIMIT, 93 94 // Note: Keep this enum in sync. with _trap_reason_name. 95 Reason_RECORDED_LIMIT = Reason_bimorphic // some are not recorded per bc 96 // Note: Reason_RECORDED_LIMIT should be < 8 to fit into 3 bits of 97 // DataLayout::trap_bits. This dependency is enforced indirectly 98 // via asserts, to avoid excessive direct header-to-header dependencies. 99 // See Deoptimization::trap_state_reason and class DataLayout. 100 }; 101 102 // What action must be taken by the runtime? 103 enum DeoptAction { 104 Action_none, // just interpret, do not invalidate nmethod 105 Action_maybe_recompile, // recompile the nmethod; need not invalidate 106 Action_reinterpret, // invalidate the nmethod, reset IC, maybe recompile 107 Action_make_not_entrant, // invalidate the nmethod, recompile (probably) 108 Action_make_not_compilable, // invalidate the nmethod and do not compile 109 Action_LIMIT 110 // Note: Keep this enum in sync. with _trap_action_name. 111 }; 112 113 enum { 114 _action_bits = 3, 115 _reason_bits = 5, 116 _debug_id_bits = 23, 117 _action_shift = 0, 118 _reason_shift = _action_shift+_action_bits, 119 _debug_id_shift = _reason_shift+_reason_bits, 120 BC_CASE_LIMIT = PRODUCT_ONLY(1) NOT_PRODUCT(4) // for _deoptimization_hist 121 }; 122 123 enum UnpackType { 124 Unpack_deopt = 0, // normal deoptimization, use pc computed in unpack_vframe_on_stack 125 Unpack_exception = 1, // exception is pending 126 Unpack_uncommon_trap = 2, // redo last byte code (C2 only) 127 Unpack_reexecute = 3, // reexecute bytecode (C1 only) 128 Unpack_LIMIT = 4 129 }; 130 131 // Checks all compiled methods. Invalid methods are deleted and 132 // corresponding activations are deoptimized. 133 static int deoptimize_dependents(); 134 135 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame 136 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map); 137 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map, DeoptReason reason); 138 139 #if INCLUDE_JVMCI 140 static address deoptimize_for_missing_exception_handler(CompiledMethod* cm); 141 #endif 142 143 private: 144 // Does the actual work for deoptimizing a single frame 145 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason); 146 147 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking 148 // is enabled 149 static void revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map); 150 // Helper function to revoke biases of all monitors in frames 151 // executing in a particular CodeBlob if UseBiasedLocking is enabled 152 static void revoke_biases_of_monitors(CodeBlob* cb); 153 154 #if COMPILER2_OR_JVMCI 155 JVMCI_ONLY(public:) 156 157 // Support for restoring non-escaping objects 158 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS); 159 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type); 160 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj); 161 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal); 162 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures); 163 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array); 164 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);) 165 #endif // COMPILER2_OR_JVMCI 166 167 public: 168 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures); 169 170 // Interface used for unpacking deoptimized frames 171 172 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob). 173 // This is only a CheapObj to ease debugging after a deopt failure 174 class UnrollBlock : public CHeapObj<mtCompiler> { 175 friend class VMStructs; 176 friend class JVMCIVMStructs; 177 private: 178 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame 179 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame 180 int _number_of_frames; // Number frames to unroll 181 int _total_frame_sizes; // Total of number*sizes frames 182 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack 183 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack 184 intptr_t* _register_block; // Block for storing callee-saved registers. 185 BasicType _return_type; // Tells if we have to restore double or long return value 186 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86) 187 int _caller_actual_parameters; // The number of actual arguments at the 188 // interpreted caller of the deoptimized frame 189 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info 190 191 // The following fields are used as temps during the unpacking phase 192 // (which is tight on registers, especially on x86). They really ought 193 // to be PD variables but that involves moving this class into its own 194 // file to use the pd include mechanism. Maybe in a later cleanup ... 195 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) 196 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) 197 public: 198 // Constructor 199 UnrollBlock(int size_of_deoptimized_frame, 200 int caller_adjustment, 201 int caller_actual_parameters, 202 int number_of_frames, 203 intptr_t* frame_sizes, 204 address* frames_pcs, 205 BasicType return_type, 206 int unpack_kind); 207 ~UnrollBlock(); 208 209 // Returns where a register is located. 210 intptr_t* value_addr_at(int register_number) const; 211 212 // Accessors 213 intptr_t* frame_sizes() const { return _frame_sizes; } 214 int number_of_frames() const { return _number_of_frames; } 215 address* frame_pcs() const { return _frame_pcs ; } 216 int unpack_kind() const { return _unpack_kind; } 217 218 // Returns the total size of frames 219 int size_of_frames() const; 220 221 void set_initial_info(intptr_t info) { _initial_info = info; } 222 223 int caller_actual_parameters() const { return _caller_actual_parameters; } 224 225 // Accessors used by the code generator for the unpack stub. 226 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } 227 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } 228 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } 229 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } 230 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } 231 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } 232 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } 233 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } 234 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } 235 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); } 236 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } 237 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } 238 239 BasicType return_type() const { return _return_type; } 240 void print(); 241 }; 242 243 //** Returns an UnrollBlock continuing information 244 // how to make room for the resulting interpreter frames. 245 // Called by assembly stub after execution has returned to 246 // deoptimized frame. 247 // @argument thread. Thread where stub_frame resides. 248 // @see OptoRuntime::deoptimization_fetch_unroll_info_C 249 static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode); 250 251 //** Unpacks vframeArray onto execution stack 252 // Called by assembly stub after execution has returned to 253 // deoptimized frame and after the stack unrolling. 254 // @argument thread. Thread where stub_frame resides. 255 // @argument exec_mode. Determines how execution should be continued in top frame. 256 // 0 means continue after current byte code 257 // 1 means exception has happened, handle exception 258 // 2 means reexecute current bytecode (for uncommon traps). 259 // @see OptoRuntime::deoptimization_unpack_frames_C 260 // Return BasicType of call return type, if any 261 static BasicType unpack_frames(JavaThread* thread, int exec_mode); 262 263 // Cleans up deoptimization bits on thread after unpacking or in the 264 // case of an exception. 265 static void cleanup_deopt_info(JavaThread *thread, 266 vframeArray * array); 267 268 // Restores callee saved values from deoptimized frame into oldest interpreter frame 269 // so caller of the deoptimized frame will get back the values it expects. 270 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); 271 272 //** Performs an uncommon trap for compiled code. 273 // The top most compiler frame is converted into interpreter frames 274 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode); 275 // Helper routine that enters the VM and may block 276 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); 277 278 //** Deoptimizes the frame identified by id. 279 // Only called from VMDeoptimizeFrame 280 // @argument thread. Thread where stub_frame resides. 281 // @argument id. id of frame that should be deoptimized. 282 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason); 283 284 // if thread is not the current thread then execute 285 // VM_DeoptimizeFrame otherwise deoptimize directly. 286 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason); 287 static void deoptimize_frame(JavaThread* thread, intptr_t* id); 288 289 // Statistics 290 static void gather_statistics(DeoptReason reason, DeoptAction action, 291 Bytecodes::Code bc = Bytecodes::_illegal); 292 static void print_statistics(); 293 294 // How much room to adjust the last frame's SP by, to make space for 295 // the callee's interpreter frame (which expects locals to be next to 296 // incoming arguments) 297 static int last_frame_adjust(int callee_parameters, int callee_locals); 298 299 // trap_request codes 300 static DeoptReason trap_request_reason(int trap_request) { 301 if (trap_request < 0) 302 return (DeoptReason) 303 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); 304 else 305 // standard reason for unloaded CP entry 306 return Reason_unloaded; 307 } 308 static DeoptAction trap_request_action(int trap_request) { 309 if (trap_request < 0) 310 return (DeoptAction) 311 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); 312 else 313 // standard action for unloaded CP entry 314 return _unloaded_action; 315 } 316 static int trap_request_debug_id(int trap_request) { 317 if (trap_request < 0) { 318 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits)); 319 } else { 320 // standard action for unloaded CP entry 321 return 0; 322 } 323 } 324 static int trap_request_index(int trap_request) { 325 if (trap_request < 0) 326 return -1; 327 else 328 return trap_request; 329 } 330 static int make_trap_request(DeoptReason reason, DeoptAction action, 331 int index = -1) { 332 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); 333 assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); 334 int trap_request; 335 if (index != -1) 336 trap_request = index; 337 else 338 trap_request = (~(((reason) << _reason_shift) 339 + ((action) << _action_shift))); 340 assert(reason == trap_request_reason(trap_request), "valid reason"); 341 assert(action == trap_request_action(trap_request), "valid action"); 342 assert(index == trap_request_index(trap_request), "valid index"); 343 return trap_request; 344 } 345 346 // The trap_state stored in a MDO is decoded here. 347 // It records two items of information. 348 // reason: If a deoptimization happened here, what its reason was, 349 // or if there were multiple deopts with differing reasons. 350 // recompiled: If a deoptimization here triggered a recompilation. 351 // Note that not all reasons are recorded per-bci. 352 static DeoptReason trap_state_reason(int trap_state); 353 static int trap_state_has_reason(int trap_state, int reason); 354 static int trap_state_add_reason(int trap_state, int reason); 355 static bool trap_state_is_recompiled(int trap_state); 356 static int trap_state_set_recompiled(int trap_state, bool z); 357 static const char* format_trap_state(char* buf, size_t buflen, 358 int trap_state); 359 360 static bool reason_is_recorded_per_bytecode(DeoptReason reason) { 361 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT; 362 } 363 364 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { 365 if (reason_is_recorded_per_bytecode(reason)) 366 return reason; 367 else if (reason == Reason_div0_check) // null check due to divide-by-zero? 368 return Reason_null_check; // recorded per BCI as a null check 369 else if (reason == Reason_speculate_class_check) 370 return Reason_class_check; 371 else if (reason == Reason_speculate_null_check) 372 return Reason_null_check; 373 else if (reason == Reason_speculate_null_assert) 374 return Reason_null_assert; 375 else if (reason == Reason_unstable_if) 376 return Reason_intrinsic; 377 else if (reason == Reason_unstable_fused_if) 378 return Reason_range_check; 379 else 380 return Reason_none; 381 } 382 383 static bool reason_is_speculate(int reason) { 384 if (reason == Reason_speculate_class_check || 385 reason == Reason_speculate_null_check || 386 reason == Reason_speculate_null_assert) { 387 return true; 388 } 389 return false; 390 } 391 392 static DeoptReason reason_null_check(bool speculative) { 393 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check; 394 } 395 396 static DeoptReason reason_class_check(bool speculative) { 397 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check; 398 } 399 400 static DeoptReason reason_null_assert(bool speculative) { 401 return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert; 402 } 403 404 static uint per_method_trap_limit(int reason) { 405 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit; 406 } 407 408 static const char* trap_reason_name(int reason); 409 static const char* trap_action_name(int action); 410 // Format like reason='foo' action='bar' index='123'. 411 // This is suitable both for XML and for tty output. 412 static const char* format_trap_request(char* buf, size_t buflen, 413 int trap_request); 414 415 static jint total_deoptimization_count(); 416 static jint deoptimization_count(DeoptReason reason); 417 418 // JVMTI PopFrame support 419 420 // Preserves incoming arguments to the popped frame when it is 421 // returning to a deoptimized caller 422 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); 423 424 static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing); 425 private: 426 // Update the mdo's count and per-BCI reason bits, returning previous state: 427 static ProfileData* query_update_method_data(MethodData* trap_mdo, 428 int trap_bci, 429 DeoptReason reason, 430 bool update_total_trap_count, 431 #if INCLUDE_JVMCI 432 bool is_osr, 433 #endif 434 Method* compiled_method, 435 //outputs: 436 uint& ret_this_trap_count, 437 bool& ret_maybe_prior_trap, 438 bool& ret_maybe_prior_recompile); 439 // class loading support for uncommon trap 440 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS); 441 static void load_class_by_index(const constantPoolHandle& constant_pool, int index); 442 443 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode); 444 445 static DeoptAction _unloaded_action; // == Action_reinterpret; 446 static const char* _trap_reason_name[]; 447 static const char* _trap_action_name[]; 448 449 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; 450 // Note: Histogram array size is 1-2 Kb. 451 452 public: 453 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason); 454 }; 455 456 class DeoptimizationMarker : StackObj { // for profiling 457 static bool _is_active; 458 public: 459 DeoptimizationMarker() { _is_active = true; } 460 ~DeoptimizationMarker() { _is_active = false; } 461 static bool is_active() { return _is_active; } 462 }; 463 464 #endif // SHARE_VM_RUNTIME_DEOPTIMIZATION_HPP