1 /* 2 * Copyright (c) 1997, 2019, 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_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 static void deoptimize_all_marked(); 139 140 private: 141 // Checks all compiled methods. Invalid methods are deleted and 142 // corresponding activations are deoptimized. 143 static int deoptimize_dependents(); 144 static void inflate_monitors_handshake(JavaThread* thread, frame fr, RegisterMap* map); 145 static void inflate_monitors(JavaThread* thread, frame fr, RegisterMap* map); 146 static void deopt_thread(bool in_handshake, JavaThread* thread, frame fr, RegisterMap *map, DeoptReason reason); 147 public: 148 149 // Deoptimizes a frame lazily. nmethod gets patched deopt happens on return to the frame 150 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *map, bool in_handshake = false); 151 static void deoptimize(JavaThread* thread, frame fr, RegisterMap *reg_map, DeoptReason reason); 152 153 #if INCLUDE_JVMCI 154 static address deoptimize_for_missing_exception_handler(CompiledMethod* cm); 155 #endif 156 157 private: 158 // Does the actual work for deoptimizing a single frame 159 static void deoptimize_single_frame(JavaThread* thread, frame fr, DeoptReason reason); 160 161 // Helper function to revoke biases of all monitors in frame if UseBiasedLocking 162 // is enabled 163 static void fix_monitors(JavaThread* thread, frame fr, RegisterMap* map) 164 { inflate_monitors(thread, fr, map); } 165 166 #if COMPILER2_OR_JVMCI 167 JVMCI_ONLY(public:) 168 169 // Support for restoring non-escaping objects 170 static bool realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS); 171 static void reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type); 172 static void reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj); 173 static void reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal); 174 static void relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures); 175 static void pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array); 176 NOT_PRODUCT(static void print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures);) 177 #endif // COMPILER2_OR_JVMCI 178 179 public: 180 static vframeArray* create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures); 181 182 // Interface used for unpacking deoptimized frames 183 184 // UnrollBlock is returned by fetch_unroll_info() to the deoptimization handler (blob). 185 // This is only a CheapObj to ease debugging after a deopt failure 186 class UnrollBlock : public CHeapObj<mtCompiler> { 187 friend class VMStructs; 188 friend class JVMCIVMStructs; 189 private: 190 int _size_of_deoptimized_frame; // Size, in bytes, of current deoptimized frame 191 int _caller_adjustment; // Adjustment, in bytes, to caller's SP by initial interpreted frame 192 int _number_of_frames; // Number frames to unroll 193 int _total_frame_sizes; // Total of number*sizes frames 194 intptr_t* _frame_sizes; // Array of frame sizes, in bytes, for unrolling the stack 195 address* _frame_pcs; // Array of frame pc's, in bytes, for unrolling the stack 196 intptr_t* _register_block; // Block for storing callee-saved registers. 197 BasicType _return_type; // Tells if we have to restore double or long return value 198 intptr_t _initial_info; // Platform dependent data for the sender frame (was FP on x86) 199 int _caller_actual_parameters; // The number of actual arguments at the 200 // interpreted caller of the deoptimized frame 201 int _unpack_kind; // exec_mode that can be changed during fetch_unroll_info 202 203 // The following fields are used as temps during the unpacking phase 204 // (which is tight on registers, especially on x86). They really ought 205 // to be PD variables but that involves moving this class into its own 206 // file to use the pd include mechanism. Maybe in a later cleanup ... 207 intptr_t _counter_temp; // SHOULD BE PD VARIABLE (x86 frame count temp) 208 intptr_t _sender_sp_temp; // SHOULD BE PD VARIABLE (x86 sender_sp) 209 public: 210 // Constructor 211 UnrollBlock(int size_of_deoptimized_frame, 212 int caller_adjustment, 213 int caller_actual_parameters, 214 int number_of_frames, 215 intptr_t* frame_sizes, 216 address* frames_pcs, 217 BasicType return_type, 218 int unpack_kind); 219 ~UnrollBlock(); 220 221 // Returns where a register is located. 222 intptr_t* value_addr_at(int register_number) const; 223 224 // Accessors 225 intptr_t* frame_sizes() const { return _frame_sizes; } 226 int number_of_frames() const { return _number_of_frames; } 227 address* frame_pcs() const { return _frame_pcs ; } 228 int unpack_kind() const { return _unpack_kind; } 229 230 // Returns the total size of frames 231 int size_of_frames() const; 232 233 void set_initial_info(intptr_t info) { _initial_info = info; } 234 235 int caller_actual_parameters() const { return _caller_actual_parameters; } 236 237 // Accessors used by the code generator for the unpack stub. 238 static int size_of_deoptimized_frame_offset_in_bytes() { return offset_of(UnrollBlock, _size_of_deoptimized_frame); } 239 static int caller_adjustment_offset_in_bytes() { return offset_of(UnrollBlock, _caller_adjustment); } 240 static int number_of_frames_offset_in_bytes() { return offset_of(UnrollBlock, _number_of_frames); } 241 static int frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _frame_sizes); } 242 static int total_frame_sizes_offset_in_bytes() { return offset_of(UnrollBlock, _total_frame_sizes); } 243 static int frame_pcs_offset_in_bytes() { return offset_of(UnrollBlock, _frame_pcs); } 244 static int register_block_offset_in_bytes() { return offset_of(UnrollBlock, _register_block); } 245 static int return_type_offset_in_bytes() { return offset_of(UnrollBlock, _return_type); } 246 static int counter_temp_offset_in_bytes() { return offset_of(UnrollBlock, _counter_temp); } 247 static int initial_info_offset_in_bytes() { return offset_of(UnrollBlock, _initial_info); } 248 static int unpack_kind_offset_in_bytes() { return offset_of(UnrollBlock, _unpack_kind); } 249 static int sender_sp_temp_offset_in_bytes() { return offset_of(UnrollBlock, _sender_sp_temp); } 250 251 BasicType return_type() const { return _return_type; } 252 void print(); 253 }; 254 255 //** Returns an UnrollBlock continuing information 256 // how to make room for the resulting interpreter frames. 257 // Called by assembly stub after execution has returned to 258 // deoptimized frame. 259 // @argument thread. Thread where stub_frame resides. 260 // @see OptoRuntime::deoptimization_fetch_unroll_info_C 261 static UnrollBlock* fetch_unroll_info(JavaThread* thread, int exec_mode); 262 263 //** Unpacks vframeArray onto execution stack 264 // Called by assembly stub after execution has returned to 265 // deoptimized frame and after the stack unrolling. 266 // @argument thread. Thread where stub_frame resides. 267 // @argument exec_mode. Determines how execution should be continued in top frame. 268 // 0 means continue after current byte code 269 // 1 means exception has happened, handle exception 270 // 2 means reexecute current bytecode (for uncommon traps). 271 // @see OptoRuntime::deoptimization_unpack_frames_C 272 // Return BasicType of call return type, if any 273 static BasicType unpack_frames(JavaThread* thread, int exec_mode); 274 275 // Cleans up deoptimization bits on thread after unpacking or in the 276 // case of an exception. 277 static void cleanup_deopt_info(JavaThread *thread, 278 vframeArray * array); 279 280 // Restores callee saved values from deoptimized frame into oldest interpreter frame 281 // so caller of the deoptimized frame will get back the values it expects. 282 static void unwind_callee_save_values(frame* f, vframeArray* vframe_array); 283 284 //** Performs an uncommon trap for compiled code. 285 // The top most compiler frame is converted into interpreter frames 286 static UnrollBlock* uncommon_trap(JavaThread* thread, jint unloaded_class_index, jint exec_mode); 287 // Helper routine that enters the VM and may block 288 static void uncommon_trap_inner(JavaThread* thread, jint unloaded_class_index); 289 290 //** Deoptimizes the frame identified by id. 291 // Only called from VMDeoptimizeFrame 292 // @argument thread. Thread where stub_frame resides. 293 // @argument id. id of frame that should be deoptimized. 294 static void deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason); 295 296 // if thread is not the current thread then execute 297 // VM_DeoptimizeFrame otherwise deoptimize directly. 298 static void deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason); 299 static void deoptimize_frame(JavaThread* thread, intptr_t* id); 300 301 // Statistics 302 static void gather_statistics(DeoptReason reason, DeoptAction action, 303 Bytecodes::Code bc = Bytecodes::_illegal); 304 static void print_statistics(); 305 306 // How much room to adjust the last frame's SP by, to make space for 307 // the callee's interpreter frame (which expects locals to be next to 308 // incoming arguments) 309 static int last_frame_adjust(int callee_parameters, int callee_locals); 310 311 // trap_request codes 312 static DeoptReason trap_request_reason(int trap_request) { 313 if (trap_request < 0) 314 return (DeoptReason) 315 ((~(trap_request) >> _reason_shift) & right_n_bits(_reason_bits)); 316 else 317 // standard reason for unloaded CP entry 318 return Reason_unloaded; 319 } 320 static DeoptAction trap_request_action(int trap_request) { 321 if (trap_request < 0) 322 return (DeoptAction) 323 ((~(trap_request) >> _action_shift) & right_n_bits(_action_bits)); 324 else 325 // standard action for unloaded CP entry 326 return _unloaded_action; 327 } 328 static int trap_request_debug_id(int trap_request) { 329 if (trap_request < 0) { 330 return ((~(trap_request) >> _debug_id_shift) & right_n_bits(_debug_id_bits)); 331 } else { 332 // standard action for unloaded CP entry 333 return 0; 334 } 335 } 336 static int trap_request_index(int trap_request) { 337 if (trap_request < 0) 338 return -1; 339 else 340 return trap_request; 341 } 342 static int make_trap_request(DeoptReason reason, DeoptAction action, 343 int index = -1) { 344 assert((1 << _reason_bits) >= Reason_LIMIT, "enough bits"); 345 assert((1 << _action_bits) >= Action_LIMIT, "enough bits"); 346 int trap_request; 347 if (index != -1) 348 trap_request = index; 349 else 350 trap_request = (~(((reason) << _reason_shift) 351 + ((action) << _action_shift))); 352 assert(reason == trap_request_reason(trap_request), "valid reason"); 353 assert(action == trap_request_action(trap_request), "valid action"); 354 assert(index == trap_request_index(trap_request), "valid index"); 355 return trap_request; 356 } 357 358 // The trap_state stored in a MDO is decoded here. 359 // It records two items of information. 360 // reason: If a deoptimization happened here, what its reason was, 361 // or if there were multiple deopts with differing reasons. 362 // recompiled: If a deoptimization here triggered a recompilation. 363 // Note that not all reasons are recorded per-bci. 364 static DeoptReason trap_state_reason(int trap_state); 365 static int trap_state_has_reason(int trap_state, int reason); 366 static int trap_state_add_reason(int trap_state, int reason); 367 static bool trap_state_is_recompiled(int trap_state); 368 static int trap_state_set_recompiled(int trap_state, bool z); 369 static const char* format_trap_state(char* buf, size_t buflen, 370 int trap_state); 371 372 static bool reason_is_recorded_per_bytecode(DeoptReason reason) { 373 return reason > Reason_none && reason <= Reason_RECORDED_LIMIT; 374 } 375 376 static DeoptReason reason_recorded_per_bytecode_if_any(DeoptReason reason) { 377 if (reason_is_recorded_per_bytecode(reason)) 378 return reason; 379 else if (reason == Reason_div0_check) // null check due to divide-by-zero? 380 return Reason_null_check; // recorded per BCI as a null check 381 else if (reason == Reason_speculate_class_check) 382 return Reason_class_check; 383 else if (reason == Reason_speculate_null_check) 384 return Reason_null_check; 385 else if (reason == Reason_speculate_null_assert) 386 return Reason_null_assert; 387 else if (reason == Reason_unstable_if) 388 return Reason_intrinsic; 389 else if (reason == Reason_unstable_fused_if) 390 return Reason_range_check; 391 else 392 return Reason_none; 393 } 394 395 static bool reason_is_speculate(int reason) { 396 if (reason == Reason_speculate_class_check || 397 reason == Reason_speculate_null_check || 398 reason == Reason_speculate_null_assert) { 399 return true; 400 } 401 return false; 402 } 403 404 static DeoptReason reason_null_check(bool speculative) { 405 return speculative ? Deoptimization::Reason_speculate_null_check : Deoptimization::Reason_null_check; 406 } 407 408 static DeoptReason reason_class_check(bool speculative) { 409 return speculative ? Deoptimization::Reason_speculate_class_check : Deoptimization::Reason_class_check; 410 } 411 412 static DeoptReason reason_null_assert(bool speculative) { 413 return speculative ? Deoptimization::Reason_speculate_null_assert : Deoptimization::Reason_null_assert; 414 } 415 416 static uint per_method_trap_limit(int reason) { 417 return reason_is_speculate(reason) ? (uint)PerMethodSpecTrapLimit : (uint)PerMethodTrapLimit; 418 } 419 420 static const char* trap_reason_name(int reason); 421 static const char* trap_action_name(int action); 422 // Format like reason='foo' action='bar' index='123'. 423 // This is suitable both for XML and for tty output. 424 static const char* format_trap_request(char* buf, size_t buflen, 425 int trap_request); 426 427 static jint total_deoptimization_count(); 428 429 // JVMTI PopFrame support 430 431 // Preserves incoming arguments to the popped frame when it is 432 // returning to a deoptimized caller 433 static void popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address); 434 435 static MethodData* get_method_data(JavaThread* thread, const methodHandle& m, bool create_if_missing); 436 private: 437 // Update the mdo's count and per-BCI reason bits, returning previous state: 438 static ProfileData* query_update_method_data(MethodData* trap_mdo, 439 int trap_bci, 440 DeoptReason reason, 441 bool update_total_trap_count, 442 #if INCLUDE_JVMCI 443 bool is_osr, 444 #endif 445 Method* compiled_method, 446 //outputs: 447 uint& ret_this_trap_count, 448 bool& ret_maybe_prior_trap, 449 bool& ret_maybe_prior_recompile); 450 // class loading support for uncommon trap 451 static void load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS); 452 static void load_class_by_index(const constantPoolHandle& constant_pool, int index); 453 454 static UnrollBlock* fetch_unroll_info_helper(JavaThread* thread, int exec_mode); 455 456 static DeoptAction _unloaded_action; // == Action_reinterpret; 457 static const char* _trap_reason_name[]; 458 static const char* _trap_action_name[]; 459 460 static juint _deoptimization_hist[Reason_LIMIT][1+Action_LIMIT][BC_CASE_LIMIT]; 461 // Note: Histogram array size is 1-2 Kb. 462 463 public: 464 static void update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason); 465 }; 466 467 class DeoptimizationMarker : StackObj { // for profiling 468 static bool _is_active; 469 public: 470 DeoptimizationMarker() { _is_active = true; } 471 ~DeoptimizationMarker() { _is_active = false; } 472 static bool is_active() { return _is_active; } 473 }; 474 475 #endif // SHARE_RUNTIME_DEOPTIMIZATION_HPP