1 /*
   2  * Copyright (c) 1997, 2023, 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 #include "precompiled.hpp"
  26 #include "classfile/javaClasses.inline.hpp"
  27 #include "classfile/symbolTable.hpp"
  28 #include "classfile/systemDictionary.hpp"
  29 #include "classfile/vmClasses.hpp"
  30 #include "code/codeCache.hpp"
  31 #include "code/debugInfoRec.hpp"
  32 #include "code/nmethod.hpp"
  33 #include "code/pcDesc.hpp"
  34 #include "code/scopeDesc.hpp"
  35 #include "compiler/compilationPolicy.hpp"
  36 #include "compiler/compilerDefinitions.inline.hpp"
  37 #include "gc/shared/collectedHeap.hpp"
  38 #include "interpreter/bytecode.hpp"
  39 #include "interpreter/bytecodeStream.hpp"
  40 #include "interpreter/interpreter.hpp"
  41 #include "interpreter/oopMapCache.hpp"
  42 #include "jvm.h"
  43 #include "logging/log.hpp"
  44 #include "logging/logLevel.hpp"
  45 #include "logging/logMessage.hpp"
  46 #include "logging/logStream.hpp"
  47 #include "memory/allocation.inline.hpp"
  48 #include "memory/oopFactory.hpp"
  49 #include "memory/resourceArea.hpp"
  50 #include "memory/universe.hpp"
  51 #include "oops/constantPool.hpp"
  52 #include "oops/flatArrayKlass.hpp"
  53 #include "oops/flatArrayOop.hpp"
  54 #include "oops/fieldStreams.inline.hpp"
  55 #include "oops/method.hpp"
  56 #include "oops/objArrayKlass.hpp"
  57 #include "oops/objArrayOop.inline.hpp"
  58 #include "oops/oop.inline.hpp"
  59 #include "oops/inlineKlass.inline.hpp"
  60 #include "oops/typeArrayOop.inline.hpp"
  61 #include "oops/verifyOopClosure.hpp"
  62 #include "prims/jvmtiDeferredUpdates.hpp"
  63 #include "prims/jvmtiExport.hpp"
  64 #include "prims/jvmtiThreadState.hpp"
  65 #include "prims/methodHandles.hpp"
  66 #include "prims/vectorSupport.hpp"
  67 #include "runtime/atomic.hpp"
  68 #include "runtime/continuation.hpp"
  69 #include "runtime/continuationEntry.inline.hpp"
  70 #include "runtime/deoptimization.hpp"
  71 #include "runtime/escapeBarrier.hpp"
  72 #include "runtime/fieldDescriptor.hpp"
  73 #include "runtime/fieldDescriptor.inline.hpp"
  74 #include "runtime/frame.inline.hpp"
  75 #include "runtime/handles.inline.hpp"
  76 #include "runtime/interfaceSupport.inline.hpp"
  77 #include "runtime/javaThread.hpp"
  78 #include "runtime/jniHandles.inline.hpp"
  79 #include "runtime/keepStackGCProcessed.hpp"
  80 #include "runtime/objectMonitor.inline.hpp"
  81 #include "runtime/osThread.hpp"
  82 #include "runtime/safepointVerifiers.hpp"
  83 #include "runtime/sharedRuntime.hpp"
  84 #include "runtime/signature.hpp"
  85 #include "runtime/stackFrameStream.inline.hpp"
  86 #include "runtime/stackValue.hpp"
  87 #include "runtime/stackWatermarkSet.hpp"
  88 #include "runtime/stubRoutines.hpp"
  89 #include "runtime/synchronizer.hpp"
  90 #include "runtime/threadSMR.hpp"
  91 #include "runtime/threadWXSetters.inline.hpp"
  92 #include "runtime/vframe.hpp"
  93 #include "runtime/vframeArray.hpp"
  94 #include "runtime/vframe_hp.hpp"
  95 #include "runtime/vmOperations.hpp"
  96 #include "utilities/checkedCast.hpp"
  97 #include "utilities/events.hpp"
  98 #include "utilities/growableArray.hpp"
  99 #include "utilities/macros.hpp"
 100 #include "utilities/preserveException.hpp"
 101 #include "utilities/xmlstream.hpp"
 102 #if INCLUDE_JFR
 103 #include "jfr/jfrEvents.hpp"
 104 #include "jfr/metadata/jfrSerializer.hpp"
 105 #endif
 106 
 107 uint64_t DeoptimizationScope::_committed_deopt_gen = 0;
 108 uint64_t DeoptimizationScope::_active_deopt_gen    = 1;
 109 bool     DeoptimizationScope::_committing_in_progress = false;
 110 
 111 DeoptimizationScope::DeoptimizationScope() : _required_gen(0) {
 112   DEBUG_ONLY(_deopted = false;)
 113 
 114   MutexLocker ml(CompiledMethod_lock, Mutex::_no_safepoint_check_flag);
 115   // If there is nothing to deopt _required_gen is the same as comitted.
 116   _required_gen = DeoptimizationScope::_committed_deopt_gen;
 117 }
 118 
 119 DeoptimizationScope::~DeoptimizationScope() {
 120   assert(_deopted, "Deopt not executed");
 121 }
 122 
 123 void DeoptimizationScope::mark(CompiledMethod* cm, bool inc_recompile_counts) {
 124   ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 125 
 126   // If it's already marked but we still need it to be deopted.
 127   if (cm->is_marked_for_deoptimization()) {
 128     dependent(cm);
 129     return;
 130   }
 131 
 132   CompiledMethod::DeoptimizationStatus status =
 133     inc_recompile_counts ? CompiledMethod::deoptimize : CompiledMethod::deoptimize_noupdate;
 134   Atomic::store(&cm->_deoptimization_status, status);
 135 
 136   // Make sure active is not committed
 137   assert(DeoptimizationScope::_committed_deopt_gen < DeoptimizationScope::_active_deopt_gen, "Must be");
 138   assert(cm->_deoptimization_generation == 0, "Is already marked");
 139 
 140   cm->_deoptimization_generation = DeoptimizationScope::_active_deopt_gen;
 141   _required_gen                  = DeoptimizationScope::_active_deopt_gen;
 142 }
 143 
 144 void DeoptimizationScope::dependent(CompiledMethod* cm) {
 145   ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 146 
 147   // A method marked by someone else may have a _required_gen lower than what we marked with.
 148   // Therefore only store it if it's higher than _required_gen.
 149   if (_required_gen < cm->_deoptimization_generation) {
 150     _required_gen = cm->_deoptimization_generation;
 151   }
 152 }
 153 
 154 void DeoptimizationScope::deoptimize_marked() {
 155   assert(!_deopted, "Already deopted");
 156 
 157   // We are not alive yet.
 158   if (!Universe::is_fully_initialized()) {
 159     DEBUG_ONLY(_deopted = true;)
 160     return;
 161   }
 162 
 163   // Safepoints are a special case, handled here.
 164   if (SafepointSynchronize::is_at_safepoint()) {
 165     DeoptimizationScope::_committed_deopt_gen = DeoptimizationScope::_active_deopt_gen;
 166     DeoptimizationScope::_active_deopt_gen++;
 167     Deoptimization::deoptimize_all_marked();
 168     DEBUG_ONLY(_deopted = true;)
 169     return;
 170   }
 171 
 172   uint64_t comitting = 0;
 173   bool wait = false;
 174   while (true) {
 175     {
 176       ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 177 
 178       // First we check if we or someone else already deopted the gen we want.
 179       if (DeoptimizationScope::_committed_deopt_gen >= _required_gen) {
 180         DEBUG_ONLY(_deopted = true;)
 181         return;
 182       }
 183       if (!_committing_in_progress) {
 184         // The version we are about to commit.
 185         comitting = DeoptimizationScope::_active_deopt_gen;
 186         // Make sure new marks use a higher gen.
 187         DeoptimizationScope::_active_deopt_gen++;
 188         _committing_in_progress = true;
 189         wait = false;
 190       } else {
 191         // Another thread is handshaking and committing a gen.
 192         wait = true;
 193       }
 194     }
 195     if (wait) {
 196       // Wait and let the concurrent handshake be performed.
 197       ThreadBlockInVM tbivm(JavaThread::current());
 198       os::naked_yield();
 199     } else {
 200       // Performs the handshake.
 201       Deoptimization::deoptimize_all_marked(); // May safepoint and an additional deopt may have occurred.
 202       DEBUG_ONLY(_deopted = true;)
 203       {
 204         ConditionalMutexLocker ml(CompiledMethod_lock, !CompiledMethod_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 205 
 206         // Make sure that committed doesn't go backwards.
 207         // Should only happen if we did a deopt during a safepoint above.
 208         if (DeoptimizationScope::_committed_deopt_gen < comitting) {
 209           DeoptimizationScope::_committed_deopt_gen = comitting;
 210         }
 211         _committing_in_progress = false;
 212 
 213         assert(DeoptimizationScope::_committed_deopt_gen >= _required_gen, "Must be");
 214 
 215         return;
 216       }
 217     }
 218   }
 219 }
 220 
 221 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
 222                                          int  caller_adjustment,
 223                                          int  caller_actual_parameters,
 224                                          int  number_of_frames,
 225                                          intptr_t* frame_sizes,
 226                                          address* frame_pcs,
 227                                          BasicType return_type,
 228                                          int exec_mode) {
 229   _size_of_deoptimized_frame = size_of_deoptimized_frame;
 230   _caller_adjustment         = caller_adjustment;
 231   _caller_actual_parameters  = caller_actual_parameters;
 232   _number_of_frames          = number_of_frames;
 233   _frame_sizes               = frame_sizes;
 234   _frame_pcs                 = frame_pcs;
 235   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
 236   _return_type               = return_type;
 237   _initial_info              = 0;
 238   // PD (x86 only)
 239   _counter_temp              = 0;
 240   _unpack_kind               = exec_mode;
 241   _sender_sp_temp            = 0;
 242 
 243   _total_frame_sizes         = size_of_frames();
 244   assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
 245 }
 246 
 247 Deoptimization::UnrollBlock::~UnrollBlock() {
 248   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
 249   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
 250   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
 251 }
 252 
 253 int Deoptimization::UnrollBlock::size_of_frames() const {
 254   // Account first for the adjustment of the initial frame
 255   intptr_t result = _caller_adjustment;
 256   for (int index = 0; index < number_of_frames(); index++) {
 257     result += frame_sizes()[index];
 258   }
 259   return checked_cast<int>(result);
 260 }
 261 
 262 void Deoptimization::UnrollBlock::print() {
 263   ResourceMark rm;
 264   stringStream st;
 265   st.print_cr("UnrollBlock");
 266   st.print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 267   st.print(   "  frame_sizes: ");
 268   for (int index = 0; index < number_of_frames(); index++) {
 269     st.print(INTX_FORMAT " ", frame_sizes()[index]);
 270   }
 271   st.cr();
 272   tty->print_raw(st.freeze());
 273 }
 274 
 275 // In order to make fetch_unroll_info work properly with escape
 276 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
 277 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
 278 // which is called from the method fetch_unroll_info_helper below.
 279 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
 280   // fetch_unroll_info() is called at the beginning of the deoptimization
 281   // handler. Note this fact before we start generating temporary frames
 282   // that can confuse an asynchronous stack walker. This counter is
 283   // decremented at the end of unpack_frames().
 284   current->inc_in_deopt_handler();
 285 
 286   if (exec_mode == Unpack_exception) {
 287     // When we get here, a callee has thrown an exception into a deoptimized
 288     // frame. That throw might have deferred stack watermark checking until
 289     // after unwinding. So we deal with such deferred requests here.
 290     StackWatermarkSet::after_unwind(current);
 291   }
 292 
 293   return fetch_unroll_info_helper(current, exec_mode);
 294 JRT_END
 295 
 296 #if COMPILER2_OR_JVMCI
 297 // print information about reallocated objects
 298 static void print_objects(JavaThread* deoptee_thread,
 299                           GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
 300   ResourceMark rm;
 301   stringStream st;  // change to logStream with logging
 302   st.print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
 303   fieldDescriptor fd;
 304 
 305   for (int i = 0; i < objects->length(); i++) {
 306     ObjectValue* sv = (ObjectValue*) objects->at(i);
 307     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
 308     Handle obj = sv->value();
 309 
 310     st.print("     object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
 311     k->print_value_on(&st);
 312     assert(obj.not_null() || k->is_inline_klass() || realloc_failures, "reallocation was missed");
 313     if (obj.is_null()) {
 314       if (k->is_inline_klass()) {
 315         st.print(" is null");
 316       } else {
 317         st.print(" allocation failed");
 318       }
 319     } else {
 320       st.print(" allocated (" SIZE_FORMAT " bytes)", obj->size() * HeapWordSize);
 321     }
 322     st.cr();
 323 
 324     if (Verbose && !obj.is_null()) {
 325       k->oop_print_on(obj(), &st);
 326     }
 327   }
 328   tty->print_raw(st.freeze());
 329 }
 330 
 331 static bool rematerialize_objects(JavaThread* thread, int exec_mode, CompiledMethod* compiled_method,
 332                                   frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
 333                                   bool& deoptimized_objects) {
 334   bool realloc_failures = false;
 335   assert (chunk->at(0)->scope() != nullptr,"expect only compiled java frames");
 336 
 337   JavaThread* deoptee_thread = chunk->at(0)->thread();
 338   assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
 339          "a frame can only be deoptimized by the owner thread");
 340 
 341   GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects_to_rematerialize(deoptee, map);
 342 
 343   // The flag return_oop() indicates call sites which return oop
 344   // in compiled code. Such sites include java method calls,
 345   // runtime calls (for example, used to allocate new objects/arrays
 346   // on slow code path) and any other calls generated in compiled code.
 347   // It is not guaranteed that we can get such information here only
 348   // by analyzing bytecode in deoptimized frames. This is why this flag
 349   // is set during method compilation (see Compile::Process_OopMap_Node()).
 350   // If the previous frame was popped or if we are dispatching an exception,
 351   // we don't have an oop result.
 352   ScopeDesc* scope = chunk->at(0)->scope();
 353   bool save_oop_result = scope->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt);
 354   // In case of the return of multiple values, we must take care
 355   // of all oop return values.
 356   GrowableArray<Handle> return_oops;
 357   InlineKlass* vk = nullptr;
 358   if (save_oop_result && scope->return_scalarized()) {
 359     vk = InlineKlass::returned_inline_klass(map);
 360     if (vk != nullptr) {
 361       vk->save_oop_fields(map, return_oops);
 362       save_oop_result = false;
 363     }
 364   }
 365   if (save_oop_result) {
 366     // Reallocation may trigger GC. If deoptimization happened on return from
 367     // call which returns oop we need to save it since it is not in oopmap.
 368     oop result = deoptee.saved_oop_result(&map);
 369     assert(oopDesc::is_oop_or_null(result), "must be oop");
 370     return_oops.push(Handle(thread, result));
 371     assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 372     if (TraceDeoptimization) {
 373       tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
 374       tty->cr();
 375     }
 376   }
 377   if (objects != nullptr || vk != nullptr) {
 378     if (exec_mode == Deoptimization::Unpack_none) {
 379       assert(thread->thread_state() == _thread_in_vm, "assumption");
 380       JavaThread* THREAD = thread; // For exception macros.
 381       // Clear pending OOM if reallocation fails and return true indicating allocation failure
 382       if (vk != nullptr) {
 383         realloc_failures = Deoptimization::realloc_inline_type_result(vk, map, return_oops, CHECK_AND_CLEAR_(true));
 384       }
 385       if (objects != nullptr) {
 386         realloc_failures = realloc_failures || Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
 387         bool skip_internal = (compiled_method != nullptr) && !compiled_method->is_compiled_by_jvmci();
 388         Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal, CHECK_AND_CLEAR_(true));
 389       }
 390       deoptimized_objects = true;
 391     } else {
 392       JavaThread* current = thread; // For JRT_BLOCK
 393       JRT_BLOCK
 394       if (vk != nullptr) {
 395         realloc_failures = Deoptimization::realloc_inline_type_result(vk, map, return_oops, THREAD);
 396       }
 397       if (objects != nullptr) {
 398         realloc_failures = realloc_failures || Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
 399         bool skip_internal = (compiled_method != nullptr) && !compiled_method->is_compiled_by_jvmci();
 400         Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal, THREAD);
 401       }
 402       JRT_END
 403     }
 404     if (TraceDeoptimization) {
 405       print_objects(deoptee_thread, objects, realloc_failures);
 406     }
 407   }
 408   if (save_oop_result || vk != nullptr) {
 409     // Restore result.
 410     assert(return_oops.length() == 1, "no inline type");
 411     deoptee.set_saved_oop_result(&map, return_oops.pop()());
 412   }
 413   return realloc_failures;
 414 }
 415 
 416 static void restore_eliminated_locks(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures,
 417                                      frame& deoptee, int exec_mode, bool& deoptimized_objects) {
 418   JavaThread* deoptee_thread = chunk->at(0)->thread();
 419   assert(!EscapeBarrier::objs_are_deoptimized(deoptee_thread, deoptee.id()), "must relock just once");
 420   assert(thread == Thread::current(), "should be");
 421   HandleMark hm(thread);
 422 #ifndef PRODUCT
 423   bool first = true;
 424 #endif // !PRODUCT
 425   for (int i = 0; i < chunk->length(); i++) {
 426     compiledVFrame* cvf = chunk->at(i);
 427     assert (cvf->scope() != nullptr,"expect only compiled java frames");
 428     GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 429     if (monitors->is_nonempty()) {
 430       bool relocked = Deoptimization::relock_objects(thread, monitors, deoptee_thread, deoptee,
 431                                                      exec_mode, realloc_failures);
 432       deoptimized_objects = deoptimized_objects || relocked;
 433 #ifndef PRODUCT
 434       if (PrintDeoptimizationDetails) {
 435         ResourceMark rm;
 436         stringStream st;
 437         for (int j = 0; j < monitors->length(); j++) {
 438           MonitorInfo* mi = monitors->at(j);
 439           if (mi->eliminated()) {
 440             if (first) {
 441               first = false;
 442               st.print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 443             }
 444             if (exec_mode == Deoptimization::Unpack_none) {
 445               ObjectMonitor* monitor = deoptee_thread->current_waiting_monitor();
 446               if (monitor != nullptr && monitor->object() == mi->owner()) {
 447                 st.print_cr("     object <" INTPTR_FORMAT "> DEFERRED relocking after wait", p2i(mi->owner()));
 448                 continue;
 449               }
 450             }
 451             if (mi->owner_is_scalar_replaced()) {
 452               Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
 453               st.print_cr("     failed reallocation for klass %s", k->external_name());
 454             } else {
 455               st.print_cr("     object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
 456             }
 457           }
 458         }
 459         tty->print_raw(st.freeze());
 460       }
 461 #endif // !PRODUCT
 462     }
 463   }
 464 }
 465 
 466 // Deoptimize objects, that is reallocate and relock them, just before they escape through JVMTI.
 467 // The given vframes cover one physical frame.
 468 bool Deoptimization::deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
 469                                                  bool& realloc_failures) {
 470   frame deoptee = chunk->at(0)->fr();
 471   JavaThread* deoptee_thread = chunk->at(0)->thread();
 472   CompiledMethod* cm = deoptee.cb()->as_compiled_method_or_null();
 473   RegisterMap map(chunk->at(0)->register_map());
 474   bool deoptimized_objects = false;
 475 
 476   bool const jvmci_enabled = JVMCI_ONLY(UseJVMCICompiler) NOT_JVMCI(false);
 477 
 478   // Reallocate the non-escaping objects and restore their fields.
 479   if (jvmci_enabled COMPILER2_PRESENT(|| (DoEscapeAnalysis && EliminateAllocations)
 480                                       || EliminateAutoBox || EnableVectorAggressiveReboxing)) {
 481     realloc_failures = rematerialize_objects(thread, Unpack_none, cm, deoptee, map, chunk, deoptimized_objects);
 482   }
 483 
 484   // MonitorInfo structures used in eliminate_locks are not GC safe.
 485   NoSafepointVerifier no_safepoint;
 486 
 487   // Now relock objects if synchronization on them was eliminated.
 488   if (jvmci_enabled COMPILER2_PRESENT(|| ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks))) {
 489     restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
 490   }
 491   return deoptimized_objects;
 492 }
 493 #endif // COMPILER2_OR_JVMCI
 494 
 495 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 496 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
 497   // When we get here we are about to unwind the deoptee frame. In order to
 498   // catch not yet safe to use frames, the following stack watermark barrier
 499   // poll will make such frames safe to use.
 500   StackWatermarkSet::before_unwind(current);
 501 
 502   // Note: there is a safepoint safety issue here. No matter whether we enter
 503   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 504   // the vframeArray is created.
 505   //
 506 
 507   // Allocate our special deoptimization ResourceMark
 508   DeoptResourceMark* dmark = new DeoptResourceMark(current);
 509   assert(current->deopt_mark() == nullptr, "Pending deopt!");
 510   current->set_deopt_mark(dmark);
 511 
 512   frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
 513   RegisterMap map(current,
 514                   RegisterMap::UpdateMap::include,
 515                   RegisterMap::ProcessFrames::include,
 516                   RegisterMap::WalkContinuation::skip);
 517   RegisterMap dummy_map(current,
 518                         RegisterMap::UpdateMap::skip,
 519                         RegisterMap::ProcessFrames::include,
 520                         RegisterMap::WalkContinuation::skip);
 521   // Now get the deoptee with a valid map
 522   frame deoptee = stub_frame.sender(&map);
 523   // Set the deoptee nmethod
 524   assert(current->deopt_compiled_method() == nullptr, "Pending deopt!");
 525   CompiledMethod* cm = deoptee.cb()->as_compiled_method_or_null();
 526   current->set_deopt_compiled_method(cm);
 527 
 528   if (VerifyStack) {
 529     current->validate_frame_layout();
 530   }
 531 
 532   // Create a growable array of VFrames where each VFrame represents an inlined
 533   // Java frame.  This storage is allocated with the usual system arena.
 534   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 535   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 536   vframe* vf = vframe::new_vframe(&deoptee, &map, current);
 537   while (!vf->is_top()) {
 538     assert(vf->is_compiled_frame(), "Wrong frame type");
 539     chunk->push(compiledVFrame::cast(vf));
 540     vf = vf->sender();
 541   }
 542   assert(vf->is_compiled_frame(), "Wrong frame type");
 543   chunk->push(compiledVFrame::cast(vf));
 544 
 545   bool realloc_failures = false;
 546 
 547 #if COMPILER2_OR_JVMCI
 548   bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
 549 
 550   // Reallocate the non-escaping objects and restore their fields. Then
 551   // relock objects if synchronization on them was eliminated.
 552   if (jvmci_enabled COMPILER2_PRESENT( || (DoEscapeAnalysis && EliminateAllocations)
 553                                        || EliminateAutoBox || EnableVectorAggressiveReboxing )) {
 554     bool unused;
 555     realloc_failures = rematerialize_objects(current, exec_mode, cm, deoptee, map, chunk, unused);
 556   }
 557 #endif // COMPILER2_OR_JVMCI
 558 
 559   // Ensure that no safepoint is taken after pointers have been stored
 560   // in fields of rematerialized objects.  If a safepoint occurs from here on
 561   // out the java state residing in the vframeArray will be missed.
 562   // Locks may be rebaised in a safepoint.
 563   NoSafepointVerifier no_safepoint;
 564 
 565 #if COMPILER2_OR_JVMCI
 566   if ((jvmci_enabled COMPILER2_PRESENT( || ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) ))
 567       && !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
 568     bool unused;
 569     restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
 570   }
 571 #endif // COMPILER2_OR_JVMCI
 572 
 573   ScopeDesc* trap_scope = chunk->at(0)->scope();
 574   Handle exceptionObject;
 575   if (trap_scope->rethrow_exception()) {
 576 #ifndef PRODUCT
 577     if (PrintDeoptimizationDetails) {
 578       tty->print_cr("Exception to be rethrown in the interpreter for method %s::%s at bci %d", trap_scope->method()->method_holder()->name()->as_C_string(), trap_scope->method()->name()->as_C_string(), trap_scope->bci());
 579     }
 580 #endif // !PRODUCT
 581 
 582     GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
 583     guarantee(expressions != nullptr && expressions->length() > 0, "must have exception to throw");
 584     ScopeValue* topOfStack = expressions->top();
 585     exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
 586     guarantee(exceptionObject() != nullptr, "exception oop can not be null");
 587   }
 588 
 589   vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
 590 #if COMPILER2_OR_JVMCI
 591   if (realloc_failures) {
 592     // This destroys all ScopedValue bindings.
 593     current->clear_scopedValueBindings();
 594     pop_frames_failed_reallocs(current, array);
 595   }
 596 #endif
 597 
 598   assert(current->vframe_array_head() == nullptr, "Pending deopt!");
 599   current->set_vframe_array_head(array);
 600 
 601   // Now that the vframeArray has been created if we have any deferred local writes
 602   // added by jvmti then we can free up that structure as the data is now in the
 603   // vframeArray
 604 
 605   JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
 606 
 607   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 608   CodeBlob* cb = stub_frame.cb();
 609   // Verify we have the right vframeArray
 610   assert(cb->frame_size() >= 0, "Unexpected frame size");
 611   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 612 
 613   // If the deopt call site is a MethodHandle invoke call site we have
 614   // to adjust the unpack_sp.
 615   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 616   if (deoptee_nm != nullptr && deoptee_nm->is_method_handle_return(deoptee.pc()))
 617     unpack_sp = deoptee.unextended_sp();
 618 
 619 #ifdef ASSERT
 620   assert(cb->is_deoptimization_stub() ||
 621          cb->is_uncommon_trap_stub() ||
 622          strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
 623          strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
 624          "unexpected code blob: %s", cb->name());
 625 #endif
 626 
 627   // This is a guarantee instead of an assert because if vframe doesn't match
 628   // we will unpack the wrong deoptimized frame and wind up in strange places
 629   // where it will be very difficult to figure out what went wrong. Better
 630   // to die an early death here than some very obscure death later when the
 631   // trail is cold.
 632   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 633   // in that it will fail to detect a problem when there is one. This needs
 634   // more work in tiger timeframe.
 635   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 636 
 637   int number_of_frames = array->frames();
 638 
 639   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 640   // virtual activation, which is the reverse of the elements in the vframes array.
 641   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 642   // +1 because we always have an interpreter return address for the final slot.
 643   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 644   int popframe_extra_args = 0;
 645   // Create an interpreter return address for the stub to use as its return
 646   // address so the skeletal frames are perfectly walkable
 647   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 648 
 649   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 650   // activation be put back on the expression stack of the caller for reexecution
 651   if (JvmtiExport::can_pop_frame() && current->popframe_forcing_deopt_reexecution()) {
 652     popframe_extra_args = in_words(current->popframe_preserved_args_size_in_words());
 653   }
 654 
 655   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 656   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 657   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 658   //
 659   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 660   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 661 
 662   // It's possible that the number of parameters at the call site is
 663   // different than number of arguments in the callee when method
 664   // handles are used.  If the caller is interpreted get the real
 665   // value so that the proper amount of space can be added to it's
 666   // frame.
 667   bool caller_was_method_handle = false;
 668   if (deopt_sender.is_interpreted_frame()) {
 669     methodHandle method(current, deopt_sender.interpreter_frame_method());
 670     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 671     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 672       // Method handle invokes may involve fairly arbitrary chains of
 673       // calls so it's impossible to know how much actual space the
 674       // caller has for locals.
 675       caller_was_method_handle = true;
 676     }
 677   }
 678 
 679   //
 680   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 681   // frame_sizes/frame_pcs[1] next oldest frame (int)
 682   // frame_sizes/frame_pcs[n] youngest frame (int)
 683   //
 684   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 685   // owns the space for the return address to it's caller).  Confusing ain't it.
 686   //
 687   // The vframe array can address vframes with indices running from
 688   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 689   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 690   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 691   // so things look a little strange in this loop.
 692   //
 693   int callee_parameters = 0;
 694   int callee_locals = 0;
 695   for (int index = 0; index < array->frames(); index++ ) {
 696     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 697     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 698     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 699     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 700                                                                                                     callee_locals,
 701                                                                                                     index == 0,
 702                                                                                                     popframe_extra_args);
 703     // This pc doesn't have to be perfect just good enough to identify the frame
 704     // as interpreted so the skeleton frame will be walkable
 705     // The correct pc will be set when the skeleton frame is completely filled out
 706     // The final pc we store in the loop is wrong and will be overwritten below
 707     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 708 
 709     callee_parameters = array->element(index)->method()->size_of_parameters();
 710     callee_locals = array->element(index)->method()->max_locals();
 711     popframe_extra_args = 0;
 712   }
 713 
 714   // Compute whether the root vframe returns a float or double value.
 715   BasicType return_type;
 716   {
 717     methodHandle method(current, array->element(0)->method());
 718     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 719     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 720   }
 721 
 722   // Compute information for handling adapters and adjusting the frame size of the caller.
 723   int caller_adjustment = 0;
 724 
 725   // Compute the amount the oldest interpreter frame will have to adjust
 726   // its caller's stack by. If the caller is a compiled frame then
 727   // we pretend that the callee has no parameters so that the
 728   // extension counts for the full amount of locals and not just
 729   // locals-parms. This is because without a c2i adapter the parm
 730   // area as created by the compiled frame will not be usable by
 731   // the interpreter. (Depending on the calling convention there
 732   // may not even be enough space).
 733 
 734   // QQQ I'd rather see this pushed down into last_frame_adjust
 735   // and have it take the sender (aka caller).
 736 
 737   if (!deopt_sender.is_interpreted_frame() || caller_was_method_handle) {
 738     caller_adjustment = last_frame_adjust(0, callee_locals);
 739   } else if (callee_locals > callee_parameters) {
 740     // The caller frame may need extending to accommodate
 741     // non-parameter locals of the first unpacked interpreted frame.
 742     // Compute that adjustment.
 743     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 744   }
 745 
 746   // If the sender is deoptimized we must retrieve the address of the handler
 747   // since the frame will "magically" show the original pc before the deopt
 748   // and we'd undo the deopt.
 749 
 750   frame_pcs[0] = Continuation::is_cont_barrier_frame(deoptee) ? StubRoutines::cont_returnBarrier() : deopt_sender.raw_pc();
 751   if (Continuation::is_continuation_enterSpecial(deopt_sender)) {
 752     ContinuationEntry::from_frame(deopt_sender)->set_argsize(0);
 753   }
 754 
 755   assert(CodeCache::find_blob(frame_pcs[0]) != nullptr, "bad pc");
 756 
 757 #if INCLUDE_JVMCI
 758   if (exceptionObject() != nullptr) {
 759     current->set_exception_oop(exceptionObject());
 760     exec_mode = Unpack_exception;
 761   }
 762 #endif
 763 
 764   if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
 765     assert(current->has_pending_exception(), "should have thrown OOME");
 766     current->set_exception_oop(current->pending_exception());
 767     current->clear_pending_exception();
 768     exec_mode = Unpack_exception;
 769   }
 770 
 771 #if INCLUDE_JVMCI
 772   if (current->frames_to_pop_failed_realloc() > 0) {
 773     current->set_pending_monitorenter(false);
 774   }
 775 #endif
 776 
 777   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 778                                       caller_adjustment * BytesPerWord,
 779                                       caller_was_method_handle ? 0 : callee_parameters,
 780                                       number_of_frames,
 781                                       frame_sizes,
 782                                       frame_pcs,
 783                                       return_type,
 784                                       exec_mode);
 785   // On some platforms, we need a way to pass some platform dependent
 786   // information to the unpacking code so the skeletal frames come out
 787   // correct (initial fp value, unextended sp, ...)
 788   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 789 
 790   if (array->frames() > 1) {
 791     if (VerifyStack && TraceDeoptimization) {
 792       tty->print_cr("Deoptimizing method containing inlining");
 793     }
 794   }
 795 
 796   array->set_unroll_block(info);
 797   return info;
 798 }
 799 
 800 // Called to cleanup deoptimization data structures in normal case
 801 // after unpacking to stack and when stack overflow error occurs
 802 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 803                                         vframeArray *array) {
 804 
 805   // Get array if coming from exception
 806   if (array == nullptr) {
 807     array = thread->vframe_array_head();
 808   }
 809   thread->set_vframe_array_head(nullptr);
 810 
 811   // Free the previous UnrollBlock
 812   vframeArray* old_array = thread->vframe_array_last();
 813   thread->set_vframe_array_last(array);
 814 
 815   if (old_array != nullptr) {
 816     UnrollBlock* old_info = old_array->unroll_block();
 817     old_array->set_unroll_block(nullptr);
 818     delete old_info;
 819     delete old_array;
 820   }
 821 
 822   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 823   // inside the vframeArray (StackValueCollections)
 824 
 825   delete thread->deopt_mark();
 826   thread->set_deopt_mark(nullptr);
 827   thread->set_deopt_compiled_method(nullptr);
 828 
 829 
 830   if (JvmtiExport::can_pop_frame()) {
 831     // Regardless of whether we entered this routine with the pending
 832     // popframe condition bit set, we should always clear it now
 833     thread->clear_popframe_condition();
 834   }
 835 
 836   // unpack_frames() is called at the end of the deoptimization handler
 837   // and (in C2) at the end of the uncommon trap handler. Note this fact
 838   // so that an asynchronous stack walker can work again. This counter is
 839   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 840   // the beginning of uncommon_trap().
 841   thread->dec_in_deopt_handler();
 842 }
 843 
 844 // Moved from cpu directories because none of the cpus has callee save values.
 845 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
 846 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
 847 
 848   // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
 849   // the days we had adapter frames. When we deoptimize a situation where a
 850   // compiled caller calls a compiled caller will have registers it expects
 851   // to survive the call to the callee. If we deoptimize the callee the only
 852   // way we can restore these registers is to have the oldest interpreter
 853   // frame that we create restore these values. That is what this routine
 854   // will accomplish.
 855 
 856   // At the moment we have modified c2 to not have any callee save registers
 857   // so this problem does not exist and this routine is just a place holder.
 858 
 859   assert(f->is_interpreted_frame(), "must be interpreted");
 860 }
 861 
 862 #ifndef PRODUCT
 863 static bool falls_through(Bytecodes::Code bc) {
 864   switch (bc) {
 865     // List may be incomplete.  Here we really only care about bytecodes where compiled code
 866     // can deoptimize.
 867     case Bytecodes::_goto:
 868     case Bytecodes::_goto_w:
 869     case Bytecodes::_athrow:
 870       return false;
 871     default:
 872       return true;
 873   }
 874 }
 875 #endif
 876 
 877 // Return BasicType of value being returned
 878 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 879   assert(thread == JavaThread::current(), "pre-condition");
 880 
 881   // We are already active in the special DeoptResourceMark any ResourceObj's we
 882   // allocate will be freed at the end of the routine.
 883 
 884   // JRT_LEAF methods don't normally allocate handles and there is a
 885   // NoHandleMark to enforce that. It is actually safe to use Handles
 886   // in a JRT_LEAF method, and sometimes desirable, but to do so we
 887   // must use ResetNoHandleMark to bypass the NoHandleMark, and
 888   // then use a HandleMark to ensure any Handles we do create are
 889   // cleaned up in this scope.
 890   ResetNoHandleMark rnhm;
 891   HandleMark hm(thread);
 892 
 893   frame stub_frame = thread->last_frame();
 894 
 895   Continuation::notify_deopt(thread, stub_frame.sp());
 896 
 897   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 898   // must point to the vframeArray for the unpack frame.
 899   vframeArray* array = thread->vframe_array_head();
 900   UnrollBlock* info = array->unroll_block();
 901 
 902   // We set the last_Java frame. But the stack isn't really parsable here. So we
 903   // clear it to make sure JFR understands not to try and walk stacks from events
 904   // in here.
 905   intptr_t* sp = thread->frame_anchor()->last_Java_sp();
 906   thread->frame_anchor()->set_last_Java_sp(nullptr);
 907 
 908   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 909   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 910 
 911   thread->frame_anchor()->set_last_Java_sp(sp);
 912 
 913   BasicType bt = info->return_type();
 914 
 915   // If we have an exception pending, claim that the return type is an oop
 916   // so the deopt_blob does not overwrite the exception_oop.
 917 
 918   if (exec_mode == Unpack_exception)
 919     bt = T_OBJECT;
 920 
 921   // Cleanup thread deopt data
 922   cleanup_deopt_info(thread, array);
 923 
 924 #ifndef PRODUCT
 925   if (VerifyStack) {
 926     ResourceMark res_mark;
 927     // Clear pending exception to not break verification code (restored afterwards)
 928     PreserveExceptionMark pm(thread);
 929 
 930     thread->validate_frame_layout();
 931 
 932     // Verify that the just-unpacked frames match the interpreter's
 933     // notions of expression stack and locals
 934     vframeArray* cur_array = thread->vframe_array_last();
 935     RegisterMap rm(thread,
 936                    RegisterMap::UpdateMap::skip,
 937                    RegisterMap::ProcessFrames::include,
 938                    RegisterMap::WalkContinuation::skip);
 939     rm.set_include_argument_oops(false);
 940     bool is_top_frame = true;
 941     int callee_size_of_parameters = 0;
 942     int callee_max_locals = 0;
 943     for (int i = 0; i < cur_array->frames(); i++) {
 944       vframeArrayElement* el = cur_array->element(i);
 945       frame* iframe = el->iframe();
 946       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 947 
 948       // Get the oop map for this bci
 949       InterpreterOopMap mask;
 950       int cur_invoke_parameter_size = 0;
 951       bool try_next_mask = false;
 952       int next_mask_expression_stack_size = -1;
 953       int top_frame_expression_stack_adjustment = 0;
 954       methodHandle mh(thread, iframe->interpreter_frame_method());
 955       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 956       BytecodeStream str(mh, iframe->interpreter_frame_bci());
 957       int max_bci = mh->code_size();
 958       // Get to the next bytecode if possible
 959       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 960       // Check to see if we can grab the number of outgoing arguments
 961       // at an uncommon trap for an invoke (where the compiler
 962       // generates debug info before the invoke has executed)
 963       Bytecodes::Code cur_code = str.next();
 964       Bytecodes::Code next_code = Bytecodes::_shouldnotreachhere;
 965       if (Bytecodes::is_invoke(cur_code)) {
 966         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 967         cur_invoke_parameter_size = invoke.size_of_parameters();
 968         if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
 969           callee_size_of_parameters++;
 970         }
 971       }
 972       if (str.bci() < max_bci) {
 973         next_code = str.next();
 974         if (next_code >= 0) {
 975           // The interpreter oop map generator reports results before
 976           // the current bytecode has executed except in the case of
 977           // calls. It seems to be hard to tell whether the compiler
 978           // has emitted debug information matching the "state before"
 979           // a given bytecode or the state after, so we try both
 980           if (!Bytecodes::is_invoke(cur_code) && falls_through(cur_code)) {
 981             // Get expression stack size for the next bytecode
 982             InterpreterOopMap next_mask;
 983             OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 984             next_mask_expression_stack_size = next_mask.expression_stack_size();
 985             if (Bytecodes::is_invoke(next_code)) {
 986               Bytecode_invoke invoke(mh, str.bci());
 987               next_mask_expression_stack_size += invoke.size_of_parameters();
 988             }
 989             // Need to subtract off the size of the result type of
 990             // the bytecode because this is not described in the
 991             // debug info but returned to the interpreter in the TOS
 992             // caching register
 993             BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 994             if (bytecode_result_type != T_ILLEGAL) {
 995               top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 996             }
 997             assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
 998             try_next_mask = true;
 999           }
1000         }
1001       }
1002 
1003       // Verify stack depth and oops in frame
1004       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
1005       if (!(
1006             /* SPARC */
1007             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
1008             /* x86 */
1009             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
1010             (try_next_mask &&
1011              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
1012                                                                     top_frame_expression_stack_adjustment))) ||
1013             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
1014             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
1015              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
1016             )) {
1017         {
1018           // Print out some information that will help us debug the problem
1019           tty->print_cr("Wrong number of expression stack elements during deoptimization");
1020           tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
1021           tty->print_cr("  Current code %s", Bytecodes::name(cur_code));
1022           if (try_next_mask) {
1023             tty->print_cr("  Next code %s", Bytecodes::name(next_code));
1024           }
1025           tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
1026                         iframe->interpreter_frame_expression_stack_size());
1027           tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
1028           tty->print_cr("  try_next_mask = %d", try_next_mask);
1029           tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
1030           tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
1031           tty->print_cr("  callee_max_locals = %d", callee_max_locals);
1032           tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
1033           tty->print_cr("  exec_mode = %d", exec_mode);
1034           tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
1035           tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
1036           tty->print_cr("  Interpreted frames:");
1037           for (int k = 0; k < cur_array->frames(); k++) {
1038             vframeArrayElement* el = cur_array->element(k);
1039             tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
1040           }
1041           cur_array->print_on_2(tty);
1042         }
1043         guarantee(false, "wrong number of expression stack elements during deopt");
1044       }
1045       VerifyOopClosure verify;
1046       iframe->oops_interpreted_do(&verify, &rm, false);
1047       callee_size_of_parameters = mh->size_of_parameters();
1048       callee_max_locals = mh->max_locals();
1049       is_top_frame = false;
1050     }
1051   }
1052 #endif // !PRODUCT
1053 
1054   return bt;
1055 JRT_END
1056 
1057 class DeoptimizeMarkedClosure : public HandshakeClosure {
1058  public:
1059   DeoptimizeMarkedClosure() : HandshakeClosure("Deoptimize") {}
1060   void do_thread(Thread* thread) {
1061     JavaThread* jt = JavaThread::cast(thread);
1062     jt->deoptimize_marked_methods();
1063   }
1064 };
1065 
1066 void Deoptimization::deoptimize_all_marked() {
1067   ResourceMark rm;
1068 
1069   // Make the dependent methods not entrant
1070   CodeCache::make_marked_nmethods_deoptimized();
1071 
1072   DeoptimizeMarkedClosure deopt;
1073   if (SafepointSynchronize::is_at_safepoint()) {
1074     Threads::java_threads_do(&deopt);
1075   } else {
1076     Handshake::execute(&deopt);
1077   }
1078 }
1079 
1080 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1081   = Deoptimization::Action_reinterpret;
1082 
1083 #if INCLUDE_JVMCI
1084 template<typename CacheType>
1085 class BoxCacheBase : public CHeapObj<mtCompiler> {
1086 protected:
1087   static InstanceKlass* find_cache_klass(Thread* thread, Symbol* klass_name) {
1088     ResourceMark rm(thread);
1089     char* klass_name_str = klass_name->as_C_string();
1090     InstanceKlass* ik = SystemDictionary::find_instance_klass(thread, klass_name, Handle(), Handle());
1091     guarantee(ik != nullptr, "%s must be loaded", klass_name_str);
1092     if (!ik->is_in_error_state()) {
1093       guarantee(ik->is_initialized(), "%s must be initialized", klass_name_str);
1094       CacheType::compute_offsets(ik);
1095     }
1096     return ik;
1097   }
1098 };
1099 
1100 template<typename PrimitiveType, typename CacheType, typename BoxType> class BoxCache  : public BoxCacheBase<CacheType> {
1101   PrimitiveType _low;
1102   PrimitiveType _high;
1103   jobject _cache;
1104 protected:
1105   static BoxCache<PrimitiveType, CacheType, BoxType> *_singleton;
1106   BoxCache(Thread* thread) {
1107     InstanceKlass* ik = BoxCacheBase<CacheType>::find_cache_klass(thread, CacheType::symbol());
1108     if (ik->is_in_error_state()) {
1109       _low = 1;
1110       _high = 0;
1111       _cache = nullptr;
1112     } else {
1113       objArrayOop cache = CacheType::cache(ik);
1114       assert(cache->length() > 0, "Empty cache");
1115       _low = BoxType::value(cache->obj_at(0));
1116       _high = checked_cast<PrimitiveType>(_low + cache->length() - 1);
1117       _cache = JNIHandles::make_global(Handle(thread, cache));
1118     }
1119   }
1120   ~BoxCache() {
1121     JNIHandles::destroy_global(_cache);
1122   }
1123 public:
1124   static BoxCache<PrimitiveType, CacheType, BoxType>* singleton(Thread* thread) {
1125     if (_singleton == nullptr) {
1126       BoxCache<PrimitiveType, CacheType, BoxType>* s = new BoxCache<PrimitiveType, CacheType, BoxType>(thread);
1127       if (!Atomic::replace_if_null(&_singleton, s)) {
1128         delete s;
1129       }
1130     }
1131     return _singleton;
1132   }
1133   oop lookup(PrimitiveType value) {
1134     if (_low <= value && value <= _high) {
1135       int offset = checked_cast<int>(value - _low);
1136       return objArrayOop(JNIHandles::resolve_non_null(_cache))->obj_at(offset);
1137     }
1138     return nullptr;
1139   }
1140   oop lookup_raw(intptr_t raw_value, bool& cache_init_error) {
1141     if (_cache == nullptr) {
1142       cache_init_error = true;
1143       return nullptr;
1144     }
1145     // Have to cast to avoid little/big-endian problems.
1146     if (sizeof(PrimitiveType) > sizeof(jint)) {
1147       jlong value = (jlong)raw_value;
1148       return lookup(value);
1149     }
1150     PrimitiveType value = (PrimitiveType)*((jint*)&raw_value);
1151     return lookup(value);
1152   }
1153 };
1154 
1155 typedef BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer> IntegerBoxCache;
1156 typedef BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long> LongBoxCache;
1157 typedef BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character> CharacterBoxCache;
1158 typedef BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short> ShortBoxCache;
1159 typedef BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte> ByteBoxCache;
1160 
1161 template<> BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>* BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>::_singleton = nullptr;
1162 template<> BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>* BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>::_singleton = nullptr;
1163 template<> BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>* BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>::_singleton = nullptr;
1164 template<> BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>* BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>::_singleton = nullptr;
1165 template<> BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>* BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>::_singleton = nullptr;
1166 
1167 class BooleanBoxCache : public BoxCacheBase<java_lang_Boolean> {
1168   jobject _true_cache;
1169   jobject _false_cache;
1170 protected:
1171   static BooleanBoxCache *_singleton;
1172   BooleanBoxCache(Thread *thread) {
1173     InstanceKlass* ik = find_cache_klass(thread, java_lang_Boolean::symbol());
1174     if (ik->is_in_error_state()) {
1175       _true_cache = nullptr;
1176       _false_cache = nullptr;
1177     } else {
1178       _true_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_TRUE(ik)));
1179       _false_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_FALSE(ik)));
1180     }
1181   }
1182   ~BooleanBoxCache() {
1183     JNIHandles::destroy_global(_true_cache);
1184     JNIHandles::destroy_global(_false_cache);
1185   }
1186 public:
1187   static BooleanBoxCache* singleton(Thread* thread) {
1188     if (_singleton == nullptr) {
1189       BooleanBoxCache* s = new BooleanBoxCache(thread);
1190       if (!Atomic::replace_if_null(&_singleton, s)) {
1191         delete s;
1192       }
1193     }
1194     return _singleton;
1195   }
1196   oop lookup_raw(intptr_t raw_value, bool& cache_in_error) {
1197     if (_true_cache == nullptr) {
1198       cache_in_error = true;
1199       return nullptr;
1200     }
1201     // Have to cast to avoid little/big-endian problems.
1202     jboolean value = (jboolean)*((jint*)&raw_value);
1203     return lookup(value);
1204   }
1205   oop lookup(jboolean value) {
1206     if (value != 0) {
1207       return JNIHandles::resolve_non_null(_true_cache);
1208     }
1209     return JNIHandles::resolve_non_null(_false_cache);
1210   }
1211 };
1212 
1213 BooleanBoxCache* BooleanBoxCache::_singleton = nullptr;
1214 
1215 oop Deoptimization::get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, bool& cache_init_error, TRAPS) {
1216    Klass* k = java_lang_Class::as_Klass(bv->klass()->as_ConstantOopReadValue()->value()());
1217    BasicType box_type = vmClasses::box_klass_type(k);
1218    if (box_type != T_OBJECT) {
1219      StackValue* value = StackValue::create_stack_value(fr, reg_map, bv->field_at(box_type == T_LONG ? 1 : 0));
1220      switch(box_type) {
1221        case T_INT:     return IntegerBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1222        case T_CHAR:    return CharacterBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1223        case T_SHORT:   return ShortBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1224        case T_BYTE:    return ByteBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1225        case T_BOOLEAN: return BooleanBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1226        case T_LONG:    return LongBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1227        default:;
1228      }
1229    }
1230    return nullptr;
1231 }
1232 #endif // INCLUDE_JVMCI
1233 
1234 #if COMPILER2_OR_JVMCI
1235 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1236   Handle pending_exception(THREAD, thread->pending_exception());
1237   const char* exception_file = thread->exception_file();
1238   int exception_line = thread->exception_line();
1239   thread->clear_pending_exception();
1240 
1241   bool failures = false;
1242 
1243   for (int i = 0; i < objects->length(); i++) {
1244     assert(objects->at(i)->is_object(), "invalid debug information");
1245     ObjectValue* sv = (ObjectValue*) objects->at(i);
1246     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1247 
1248     // Check if the object may be null and has an additional is_init input that needs
1249     // to be checked before using the field values. Skip re-allocation if it is null.
1250     if (sv->maybe_null()) {
1251       assert(k->is_inline_klass(), "must be an inline klass");
1252       jint is_init = StackValue::create_stack_value(fr, reg_map, sv->is_init())->get_jint();
1253       if (is_init == 0) {
1254         continue;
1255       }
1256     }
1257 
1258     oop obj = nullptr;
1259     bool cache_init_error = false;
1260     if (k->is_instance_klass()) {
1261 #if INCLUDE_JVMCI
1262       CompiledMethod* cm = fr->cb()->as_compiled_method_or_null();
1263       if (cm->is_compiled_by_jvmci() && sv->is_auto_box()) {
1264         AutoBoxObjectValue* abv = (AutoBoxObjectValue*) sv;
1265         obj = get_cached_box(abv, fr, reg_map, cache_init_error, THREAD);
1266         if (obj != nullptr) {
1267           // Set the flag to indicate the box came from a cache, so that we can skip the field reassignment for it.
1268           abv->set_cached(true);
1269         } else if (cache_init_error) {
1270           // Results in an OOME which is valid (as opposed to a class initialization error)
1271           // and is fine for the rare case a cache initialization failing.
1272           failures = true;
1273         }
1274       }
1275 #endif // INCLUDE_JVMCI
1276 
1277       InstanceKlass* ik = InstanceKlass::cast(k);
1278       if (obj == nullptr && !cache_init_error) {
1279 #if COMPILER2_OR_JVMCI
1280         if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1281           obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1282         } else {
1283           obj = ik->allocate_instance(THREAD);
1284         }
1285 #else
1286         obj = ik->allocate_instance(THREAD);
1287 #endif // COMPILER2_OR_JVMCI
1288       }
1289     } else if (k->is_flatArray_klass()) {
1290       FlatArrayKlass* ak = FlatArrayKlass::cast(k);
1291       // Inline type array must be zeroed because not all memory is reassigned
1292       obj = ak->allocate(sv->field_size(), THREAD);
1293     } else if (k->is_typeArray_klass()) {
1294       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1295       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1296       int len = sv->field_size() / type2size[ak->element_type()];
1297       obj = ak->allocate(len, THREAD);
1298     } else if (k->is_objArray_klass()) {
1299       ObjArrayKlass* ak = ObjArrayKlass::cast(k);
1300       obj = ak->allocate(sv->field_size(), THREAD);
1301     }
1302 
1303     if (obj == nullptr) {
1304       failures = true;
1305     }
1306 
1307     assert(sv->value().is_null(), "redundant reallocation");
1308     assert(obj != nullptr || HAS_PENDING_EXCEPTION || cache_init_error, "allocation should succeed or we should get an exception");
1309     CLEAR_PENDING_EXCEPTION;
1310     sv->set_value(obj);
1311   }
1312 
1313   if (failures) {
1314     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1315   } else if (pending_exception.not_null()) {
1316     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1317   }
1318 
1319   return failures;
1320 }
1321 
1322 // We're deoptimizing at the return of a call, inline type fields are
1323 // in registers. When we go back to the interpreter, it will expect a
1324 // reference to an inline type instance. Allocate and initialize it from
1325 // the register values here.
1326 bool Deoptimization::realloc_inline_type_result(InlineKlass* vk, const RegisterMap& map, GrowableArray<Handle>& return_oops, TRAPS) {
1327   oop new_vt = vk->realloc_result(map, return_oops, THREAD);
1328   if (new_vt == nullptr) {
1329     CLEAR_PENDING_EXCEPTION;
1330     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), true);
1331   }
1332   return_oops.clear();
1333   return_oops.push(Handle(THREAD, new_vt));
1334   return false;
1335 }
1336 
1337 #if INCLUDE_JVMCI
1338 /**
1339  * For primitive types whose kind gets "erased" at runtime (shorts become stack ints),
1340  * we need to somehow be able to recover the actual kind to be able to write the correct
1341  * amount of bytes.
1342  * For that purpose, this method assumes that, for an entry spanning n bytes at index i,
1343  * the entries at index n + 1 to n + i are 'markers'.
1344  * For example, if we were writing a short at index 4 of a byte array of size 8, the
1345  * expected form of the array would be:
1346  *
1347  * {b0, b1, b2, b3, INT, marker, b6, b7}
1348  *
1349  * Thus, in order to get back the size of the entry, we simply need to count the number
1350  * of marked entries
1351  *
1352  * @param virtualArray the virtualized byte array
1353  * @param i index of the virtual entry we are recovering
1354  * @return The number of bytes the entry spans
1355  */
1356 static int count_number_of_bytes_for_entry(ObjectValue *virtualArray, int i) {
1357   int index = i;
1358   while (++index < virtualArray->field_size() &&
1359            virtualArray->field_at(index)->is_marker()) {}
1360   return index - i;
1361 }
1362 
1363 /**
1364  * If there was a guarantee for byte array to always start aligned to a long, we could
1365  * do a simple check on the parity of the index. Unfortunately, that is not always the
1366  * case. Thus, we check alignment of the actual address we are writing to.
1367  * In the unlikely case index 0 is 5-aligned for example, it would then be possible to
1368  * write a long to index 3.
1369  */
1370 static jbyte* check_alignment_get_addr(typeArrayOop obj, int index, int expected_alignment) {
1371     jbyte* res = obj->byte_at_addr(index);
1372     assert((((intptr_t) res) % expected_alignment) == 0, "Non-aligned write");
1373     return res;
1374 }
1375 
1376 static void byte_array_put(typeArrayOop obj, StackValue* value, int index, int byte_count) {
1377   switch (byte_count) {
1378     case 1:
1379       obj->byte_at_put(index, (jbyte) value->get_jint());
1380       break;
1381     case 2:
1382       *((jshort *) check_alignment_get_addr(obj, index, 2)) = (jshort) value->get_jint();
1383       break;
1384     case 4:
1385       *((jint *) check_alignment_get_addr(obj, index, 4)) = value->get_jint();
1386       break;
1387     case 8:
1388       *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) value->get_intptr();
1389       break;
1390     default:
1391       ShouldNotReachHere();
1392   }
1393 }
1394 #endif // INCLUDE_JVMCI
1395 
1396 
1397 // restore elements of an eliminated type array
1398 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1399   int index = 0;
1400 
1401   for (int i = 0; i < sv->field_size(); i++) {
1402     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1403     switch(type) {
1404     case T_LONG: case T_DOUBLE: {
1405       assert(value->type() == T_INT, "Agreement.");
1406       StackValue* low =
1407         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1408 #ifdef _LP64
1409       jlong res = (jlong)low->get_intptr();
1410 #else
1411       jlong res = jlong_from(value->get_jint(), low->get_jint());
1412 #endif
1413       obj->long_at_put(index, res);
1414       break;
1415     }
1416 
1417     case T_INT: case T_FLOAT: { // 4 bytes.
1418       assert(value->type() == T_INT, "Agreement.");
1419       bool big_value = false;
1420       if (i + 1 < sv->field_size() && type == T_INT) {
1421         if (sv->field_at(i)->is_location()) {
1422           Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
1423           if (type == Location::dbl || type == Location::lng) {
1424             big_value = true;
1425           }
1426         } else if (sv->field_at(i)->is_constant_int()) {
1427           ScopeValue* next_scope_field = sv->field_at(i + 1);
1428           if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1429             big_value = true;
1430           }
1431         }
1432       }
1433 
1434       if (big_value) {
1435         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1436   #ifdef _LP64
1437         jlong res = (jlong)low->get_intptr();
1438   #else
1439         jlong res = jlong_from(value->get_jint(), low->get_jint());
1440   #endif
1441         obj->int_at_put(index, *(jint*)&res);
1442         obj->int_at_put(++index, *((jint*)&res + 1));
1443       } else {
1444         obj->int_at_put(index, value->get_jint());
1445       }
1446       break;
1447     }
1448 
1449     case T_SHORT:
1450       assert(value->type() == T_INT, "Agreement.");
1451       obj->short_at_put(index, (jshort)value->get_jint());
1452       break;
1453 
1454     case T_CHAR:
1455       assert(value->type() == T_INT, "Agreement.");
1456       obj->char_at_put(index, (jchar)value->get_jint());
1457       break;
1458 
1459     case T_BYTE: {
1460       assert(value->type() == T_INT, "Agreement.");
1461 #if INCLUDE_JVMCI
1462       // The value we get is erased as a regular int. We will need to find its actual byte count 'by hand'.
1463       int byte_count = count_number_of_bytes_for_entry(sv, i);
1464       byte_array_put(obj, value, index, byte_count);
1465       // According to byte_count contract, the values from i + 1 to i + byte_count are illegal values. Skip.
1466       i += byte_count - 1; // Balance the loop counter.
1467       index += byte_count;
1468       // index has been updated so continue at top of loop
1469       continue;
1470 #else
1471       obj->byte_at_put(index, (jbyte)value->get_jint());
1472       break;
1473 #endif // INCLUDE_JVMCI
1474     }
1475 
1476     case T_BOOLEAN: {
1477       assert(value->type() == T_INT, "Agreement.");
1478       obj->bool_at_put(index, (jboolean)value->get_jint());
1479       break;
1480     }
1481 
1482       default:
1483         ShouldNotReachHere();
1484     }
1485     index++;
1486   }
1487 }
1488 
1489 // restore fields of an eliminated object array
1490 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1491   for (int i = 0; i < sv->field_size(); i++) {
1492     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1493     assert(value->type() == T_OBJECT, "object element expected");
1494     obj->obj_at_put(i, value->get_obj()());
1495   }
1496 }
1497 
1498 class ReassignedField {
1499 public:
1500   int _offset;
1501   BasicType _type;
1502   InstanceKlass* _klass;
1503   bool _is_flat;
1504 public:
1505   ReassignedField() : _offset(0), _type(T_ILLEGAL), _klass(nullptr), _is_flat(false) { }
1506 };
1507 
1508 int compare(ReassignedField* left, ReassignedField* right) {
1509   return left->_offset - right->_offset;
1510 }
1511 
1512 // Restore fields of an eliminated instance object using the same field order
1513 // returned by HotSpotResolvedObjectTypeImpl.getInstanceFields(true)
1514 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool skip_internal, int base_offset, TRAPS) {
1515   GrowableArray<ReassignedField>* fields = new GrowableArray<ReassignedField>();
1516   InstanceKlass* ik = klass;
1517   while (ik != nullptr) {
1518     for (AllFieldStream fs(ik); !fs.done(); fs.next()) {
1519       if (!fs.access_flags().is_static() && (!skip_internal || !fs.field_flags().is_injected())) {
1520         ReassignedField field;
1521         field._offset = fs.offset();
1522         field._type = Signature::basic_type(fs.signature());
1523         if (fs.is_null_free_inline_type()) {
1524           if (fs.is_flat()) {
1525             field._is_flat = true;
1526             // Resolve klass of flat inline type field
1527             field._klass = InlineKlass::cast(klass->get_inline_type_field_klass(fs.index()));
1528           } else {
1529             field._type = T_OBJECT;  // Can be removed once Q-descriptors have been removed.
1530           }
1531         }
1532         fields->append(field);
1533       }
1534     }
1535     ik = ik->superklass();
1536   }
1537   fields->sort(compare);
1538   for (int i = 0; i < fields->length(); i++) {
1539     BasicType type = fields->at(i)._type;
1540     int offset = base_offset + fields->at(i)._offset;
1541     // Check for flat inline type field before accessing the ScopeValue because it might not have any fields
1542     if (fields->at(i)._is_flat) {
1543       // Recursively re-assign flat inline type fields
1544       InstanceKlass* vk = fields->at(i)._klass;
1545       assert(vk != nullptr, "must be resolved");
1546       offset -= InlineKlass::cast(vk)->first_field_offset(); // Adjust offset to omit oop header
1547       svIndex = reassign_fields_by_klass(vk, fr, reg_map, sv, svIndex, obj, skip_internal, offset, CHECK_0);
1548       continue; // Continue because we don't need to increment svIndex
1549     }
1550     ScopeValue* scope_field = sv->field_at(svIndex);
1551     StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1552     switch (type) {
1553       case T_OBJECT:
1554       case T_ARRAY:
1555         assert(value->type() == T_OBJECT, "Agreement.");
1556         obj->obj_field_put(offset, value->get_obj()());
1557         break;
1558 
1559       case T_INT: case T_FLOAT: { // 4 bytes.
1560         assert(value->type() == T_INT, "Agreement.");
1561         bool big_value = false;
1562         if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1563           if (scope_field->is_location()) {
1564             Location::Type type = ((LocationValue*) scope_field)->location().type();
1565             if (type == Location::dbl || type == Location::lng) {
1566               big_value = true;
1567             }
1568           }
1569           if (scope_field->is_constant_int()) {
1570             ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1571             if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1572               big_value = true;
1573             }
1574           }
1575         }
1576 
1577         if (big_value) {
1578           i++;
1579           assert(i < fields->length(), "second T_INT field needed");
1580           assert(fields->at(i)._type == T_INT, "T_INT field needed");
1581         } else {
1582           obj->int_field_put(offset, value->get_jint());
1583           break;
1584         }
1585       }
1586         /* no break */
1587 
1588       case T_LONG: case T_DOUBLE: {
1589         assert(value->type() == T_INT, "Agreement.");
1590         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1591 #ifdef _LP64
1592         jlong res = (jlong)low->get_intptr();
1593 #else
1594         jlong res = jlong_from(value->get_jint(), low->get_jint());
1595 #endif
1596         obj->long_field_put(offset, res);
1597         break;
1598       }
1599 
1600       case T_SHORT:
1601         assert(value->type() == T_INT, "Agreement.");
1602         obj->short_field_put(offset, (jshort)value->get_jint());
1603         break;
1604 
1605       case T_CHAR:
1606         assert(value->type() == T_INT, "Agreement.");
1607         obj->char_field_put(offset, (jchar)value->get_jint());
1608         break;
1609 
1610       case T_BYTE:
1611         assert(value->type() == T_INT, "Agreement.");
1612         obj->byte_field_put(offset, (jbyte)value->get_jint());
1613         break;
1614 
1615       case T_BOOLEAN:
1616         assert(value->type() == T_INT, "Agreement.");
1617         obj->bool_field_put(offset, (jboolean)value->get_jint());
1618         break;
1619 
1620       default:
1621         ShouldNotReachHere();
1622     }
1623     svIndex++;
1624   }
1625   return svIndex;
1626 }
1627 
1628 // restore fields of an eliminated inline type array
1629 void Deoptimization::reassign_flat_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, flatArrayOop obj, FlatArrayKlass* vak, bool skip_internal, TRAPS) {
1630   InlineKlass* vk = vak->element_klass();
1631   assert(vk->flat_array(), "should only be used for flat inline type arrays");
1632   // Adjust offset to omit oop header
1633   int base_offset = arrayOopDesc::base_offset_in_bytes(T_PRIMITIVE_OBJECT) - InlineKlass::cast(vk)->first_field_offset();
1634   // Initialize all elements of the flat inline type array
1635   for (int i = 0; i < sv->field_size(); i++) {
1636     ScopeValue* val = sv->field_at(i);
1637     int offset = base_offset + (i << Klass::layout_helper_log2_element_size(vak->layout_helper()));
1638     reassign_fields_by_klass(vk, fr, reg_map, val->as_ObjectValue(), 0, (oop)obj, skip_internal, offset, CHECK);
1639   }
1640 }
1641 
1642 // restore fields of all eliminated objects and arrays
1643 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal, TRAPS) {
1644   for (int i = 0; i < objects->length(); i++) {
1645     assert(objects->at(i)->is_object(), "invalid debug information");
1646     ObjectValue* sv = (ObjectValue*) objects->at(i);
1647     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1648     Handle obj = sv->value();
1649     assert(obj.not_null() || realloc_failures || sv->maybe_null(), "reallocation was missed");
1650 #ifndef PRODUCT
1651     if (PrintDeoptimizationDetails) {
1652       tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1653     }
1654 #endif // !PRODUCT
1655 
1656     if (obj.is_null()) {
1657       continue;
1658     }
1659 
1660 #if INCLUDE_JVMCI
1661     // Don't reassign fields of boxes that came from a cache. Caches may be in CDS.
1662     if (sv->is_auto_box() && ((AutoBoxObjectValue*) sv)->is_cached()) {
1663       continue;
1664     }
1665 #endif // INCLUDE_JVMCI
1666 #if COMPILER2_OR_JVMCI
1667     if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1668       assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1669       ScopeValue* payload = sv->field_at(0);
1670       if (payload->is_location() &&
1671           payload->as_LocationValue()->location().type() == Location::vector) {
1672 #ifndef PRODUCT
1673         if (PrintDeoptimizationDetails) {
1674           tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1675           if (Verbose) {
1676             Handle obj = sv->value();
1677             k->oop_print_on(obj(), tty);
1678           }
1679         }
1680 #endif // !PRODUCT
1681         continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1682       }
1683       // Else fall-through to do assignment for scalar-replaced boxed vector representation
1684       // which could be restored after vector object allocation.
1685     }
1686 #endif /* !COMPILER2_OR_JVMCI */
1687     if (k->is_instance_klass()) {
1688       InstanceKlass* ik = InstanceKlass::cast(k);
1689       reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), skip_internal, 0, CHECK);
1690     } else if (k->is_flatArray_klass()) {
1691       FlatArrayKlass* vak = FlatArrayKlass::cast(k);
1692       reassign_flat_array_elements(fr, reg_map, sv, (flatArrayOop) obj(), vak, skip_internal, CHECK);
1693     } else if (k->is_typeArray_klass()) {
1694       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1695       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1696     } else if (k->is_objArray_klass()) {
1697       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1698     }
1699   }
1700 }
1701 
1702 
1703 // relock objects for which synchronization was eliminated
1704 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1705                                     JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1706   bool relocked_objects = false;
1707   for (int i = 0; i < monitors->length(); i++) {
1708     MonitorInfo* mon_info = monitors->at(i);
1709     if (mon_info->eliminated()) {
1710       assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1711       relocked_objects = true;
1712       if (!mon_info->owner_is_scalar_replaced()) {
1713         Handle obj(thread, mon_info->owner());
1714         markWord mark = obj->mark();
1715         if (exec_mode == Unpack_none) {
1716           if (LockingMode == LM_LEGACY && mark.has_locker() && fr.sp() > (intptr_t*)mark.locker()) {
1717             // With exec_mode == Unpack_none obj may be thread local and locked in
1718             // a callee frame. Make the lock in the callee a recursive lock and restore the displaced header.
1719             markWord dmw = mark.displaced_mark_helper();
1720             mark.locker()->set_displaced_header(markWord::encode((BasicLock*) nullptr));
1721             obj->set_mark(dmw);
1722           }
1723           if (mark.has_monitor()) {
1724             // defer relocking if the deoptee thread is currently waiting for obj
1725             ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1726             if (waiting_monitor != nullptr && waiting_monitor->object() == obj()) {
1727               assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1728               mon_info->lock()->set_displaced_header(markWord::unused_mark());
1729               JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1730               continue;
1731             }
1732           }
1733         }
1734         if (LockingMode == LM_LIGHTWEIGHT && exec_mode == Unpack_none) {
1735           // We have lost information about the correct state of the lock stack.
1736           // Inflate the locks instead. Enter then inflate to avoid races with
1737           // deflation.
1738           ObjectSynchronizer::enter(obj, nullptr, deoptee_thread);
1739           assert(mon_info->owner()->is_locked(), "object must be locked now");
1740           ObjectMonitor* mon = ObjectSynchronizer::inflate(deoptee_thread, obj(), ObjectSynchronizer::inflate_cause_vm_internal);
1741           assert(mon->owner() == deoptee_thread, "must be");
1742         } else {
1743           BasicLock* lock = mon_info->lock();
1744           ObjectSynchronizer::enter(obj, lock, deoptee_thread);
1745           assert(mon_info->owner()->is_locked(), "object must be locked now");
1746         }
1747       }
1748     }
1749   }
1750   return relocked_objects;
1751 }
1752 #endif // COMPILER2_OR_JVMCI
1753 
1754 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1755   Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1756 
1757   // Register map for next frame (used for stack crawl).  We capture
1758   // the state of the deopt'ing frame's caller.  Thus if we need to
1759   // stuff a C2I adapter we can properly fill in the callee-save
1760   // register locations.
1761   frame caller = fr.sender(reg_map);
1762   int frame_size = pointer_delta_as_int(caller.sp(), fr.sp());
1763 
1764   frame sender = caller;
1765 
1766   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1767   // the vframeArray containing the unpacking information is allocated in the C heap.
1768   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1769   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1770 
1771   // Compare the vframeArray to the collected vframes
1772   assert(array->structural_compare(thread, chunk), "just checking");
1773 
1774   if (TraceDeoptimization) {
1775     ResourceMark rm;
1776     stringStream st;
1777     st.print_cr("DEOPT PACKING thread=" INTPTR_FORMAT " vframeArray=" INTPTR_FORMAT, p2i(thread), p2i(array));
1778     st.print("   ");
1779     fr.print_on(&st);
1780     st.print_cr("   Virtual frames (innermost/newest first):");
1781     for (int index = 0; index < chunk->length(); index++) {
1782       compiledVFrame* vf = chunk->at(index);
1783       int bci = vf->raw_bci();
1784       const char* code_name;
1785       if (bci == SynchronizationEntryBCI) {
1786         code_name = "sync entry";
1787       } else {
1788         Bytecodes::Code code = vf->method()->code_at(bci);
1789         code_name = Bytecodes::name(code);
1790       }
1791 
1792       st.print("      VFrame %d (" INTPTR_FORMAT ")", index, p2i(vf));
1793       st.print(" - %s", vf->method()->name_and_sig_as_C_string());
1794       st.print(" - %s", code_name);
1795       st.print_cr(" @ bci=%d ", bci);
1796     }
1797     tty->print_raw(st.freeze());
1798     tty->cr();
1799   }
1800 
1801   return array;
1802 }
1803 
1804 #if COMPILER2_OR_JVMCI
1805 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1806   // Reallocation of some scalar replaced objects failed. Record
1807   // that we need to pop all the interpreter frames for the
1808   // deoptimized compiled frame.
1809   assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1810   thread->set_frames_to_pop_failed_realloc(array->frames());
1811   // Unlock all monitors here otherwise the interpreter will see a
1812   // mix of locked and unlocked monitors (because of failed
1813   // reallocations of synchronized objects) and be confused.
1814   for (int i = 0; i < array->frames(); i++) {
1815     MonitorChunk* monitors = array->element(i)->monitors();
1816     if (monitors != nullptr) {
1817       for (int j = 0; j < monitors->number_of_monitors(); j++) {
1818         BasicObjectLock* src = monitors->at(j);
1819         if (src->obj() != nullptr) {
1820           ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1821         }
1822       }
1823       array->element(i)->free_monitors(thread);
1824 #ifdef ASSERT
1825       array->element(i)->set_removed_monitors();
1826 #endif
1827     }
1828   }
1829 }
1830 #endif
1831 
1832 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1833   assert(fr.can_be_deoptimized(), "checking frame type");
1834 
1835   gather_statistics(reason, Action_none, Bytecodes::_illegal);
1836 
1837   if (LogCompilation && xtty != nullptr) {
1838     CompiledMethod* cm = fr.cb()->as_compiled_method_or_null();
1839     assert(cm != nullptr, "only compiled methods can deopt");
1840 
1841     ttyLocker ttyl;
1842     xtty->begin_head("deoptimized thread='" UINTX_FORMAT "' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1843     cm->log_identity(xtty);
1844     xtty->end_head();
1845     for (ScopeDesc* sd = cm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1846       xtty->begin_elem("jvms bci='%d'", sd->bci());
1847       xtty->method(sd->method());
1848       xtty->end_elem();
1849       if (sd->is_top())  break;
1850     }
1851     xtty->tail("deoptimized");
1852   }
1853 
1854   Continuation::notify_deopt(thread, fr.sp());
1855 
1856   // Patch the compiled method so that when execution returns to it we will
1857   // deopt the execution state and return to the interpreter.
1858   fr.deoptimize(thread);
1859 }
1860 
1861 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1862   // Deoptimize only if the frame comes from compiled code.
1863   // Do not deoptimize the frame which is already patched
1864   // during the execution of the loops below.
1865   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1866     return;
1867   }
1868   ResourceMark rm;
1869   deoptimize_single_frame(thread, fr, reason);
1870 }
1871 
1872 #if INCLUDE_JVMCI
1873 address Deoptimization::deoptimize_for_missing_exception_handler(CompiledMethod* cm) {
1874   // there is no exception handler for this pc => deoptimize
1875   cm->make_not_entrant();
1876 
1877   // Use Deoptimization::deoptimize for all of its side-effects:
1878   // gathering traps statistics, logging...
1879   // it also patches the return pc but we do not care about that
1880   // since we return a continuation to the deopt_blob below.
1881   JavaThread* thread = JavaThread::current();
1882   RegisterMap reg_map(thread,
1883                       RegisterMap::UpdateMap::skip,
1884                       RegisterMap::ProcessFrames::include,
1885                       RegisterMap::WalkContinuation::skip);
1886   frame runtime_frame = thread->last_frame();
1887   frame caller_frame = runtime_frame.sender(&reg_map);
1888   assert(caller_frame.cb()->as_compiled_method_or_null() == cm, "expect top frame compiled method");
1889   vframe* vf = vframe::new_vframe(&caller_frame, &reg_map, thread);
1890   compiledVFrame* cvf = compiledVFrame::cast(vf);
1891   ScopeDesc* imm_scope = cvf->scope();
1892   MethodData* imm_mdo = get_method_data(thread, methodHandle(thread, imm_scope->method()), true);
1893   if (imm_mdo != nullptr) {
1894     ProfileData* pdata = imm_mdo->allocate_bci_to_data(imm_scope->bci(), nullptr);
1895     if (pdata != nullptr && pdata->is_BitData()) {
1896       BitData* bit_data = (BitData*) pdata;
1897       bit_data->set_exception_seen();
1898     }
1899   }
1900 
1901   Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1902 
1903   MethodData* trap_mdo = get_method_data(thread, methodHandle(thread, cm->method()), true);
1904   if (trap_mdo != nullptr) {
1905     trap_mdo->inc_trap_count(Deoptimization::Reason_not_compiled_exception_handler);
1906   }
1907 
1908   return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1909 }
1910 #endif
1911 
1912 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1913   assert(thread == Thread::current() ||
1914          thread->is_handshake_safe_for(Thread::current()) ||
1915          SafepointSynchronize::is_at_safepoint(),
1916          "can only deoptimize other thread at a safepoint/handshake");
1917   // Compute frame and register map based on thread and sp.
1918   RegisterMap reg_map(thread,
1919                       RegisterMap::UpdateMap::skip,
1920                       RegisterMap::ProcessFrames::include,
1921                       RegisterMap::WalkContinuation::skip);
1922   frame fr = thread->last_frame();
1923   while (fr.id() != id) {
1924     fr = fr.sender(&reg_map);
1925   }
1926   deoptimize(thread, fr, reason);
1927 }
1928 
1929 
1930 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1931   Thread* current = Thread::current();
1932   if (thread == current || thread->is_handshake_safe_for(current)) {
1933     Deoptimization::deoptimize_frame_internal(thread, id, reason);
1934   } else {
1935     VM_DeoptimizeFrame deopt(thread, id, reason);
1936     VMThread::execute(&deopt);
1937   }
1938 }
1939 
1940 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1941   deoptimize_frame(thread, id, Reason_constraint);
1942 }
1943 
1944 // JVMTI PopFrame support
1945 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1946 {
1947   assert(thread == JavaThread::current(), "pre-condition");
1948   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1949 }
1950 JRT_END
1951 
1952 MethodData*
1953 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1954                                 bool create_if_missing) {
1955   JavaThread* THREAD = thread; // For exception macros.
1956   MethodData* mdo = m()->method_data();
1957   if (mdo == nullptr && create_if_missing && !HAS_PENDING_EXCEPTION) {
1958     // Build an MDO.  Ignore errors like OutOfMemory;
1959     // that simply means we won't have an MDO to update.
1960     Method::build_profiling_method_data(m, THREAD);
1961     if (HAS_PENDING_EXCEPTION) {
1962       // Only metaspace OOM is expected. No Java code executed.
1963       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1964       CLEAR_PENDING_EXCEPTION;
1965     }
1966     mdo = m()->method_data();
1967   }
1968   return mdo;
1969 }
1970 
1971 #if COMPILER2_OR_JVMCI
1972 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1973   // In case of an unresolved klass entry, load the class.
1974   // This path is exercised from case _ldc in Parse::do_one_bytecode,
1975   // and probably nowhere else.
1976   // Even that case would benefit from simply re-interpreting the
1977   // bytecode, without paying special attention to the class index.
1978   // So this whole "class index" feature should probably be removed.
1979 
1980   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1981     Klass* tk = constant_pool->klass_at(index, THREAD);
1982     if (HAS_PENDING_EXCEPTION) {
1983       // Exception happened during classloading. We ignore the exception here, since it
1984       // is going to be rethrown since the current activation is going to be deoptimized and
1985       // the interpreter will re-execute the bytecode.
1986       // Do not clear probable Async Exceptions.
1987       CLEAR_PENDING_NONASYNC_EXCEPTION;
1988       // Class loading called java code which may have caused a stack
1989       // overflow. If the exception was thrown right before the return
1990       // to the runtime the stack is no longer guarded. Reguard the
1991       // stack otherwise if we return to the uncommon trap blob and the
1992       // stack bang causes a stack overflow we crash.
1993       JavaThread* jt = THREAD;
1994       bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1995       assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1996     }
1997     return;
1998   }
1999 
2000   assert(!constant_pool->tag_at(index).is_symbol(),
2001          "no symbolic names here, please");
2002 }
2003 
2004 #if INCLUDE_JFR
2005 
2006 class DeoptReasonSerializer : public JfrSerializer {
2007  public:
2008   void serialize(JfrCheckpointWriter& writer) {
2009     writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
2010     for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
2011       writer.write_key((u8)i);
2012       writer.write(Deoptimization::trap_reason_name(i));
2013     }
2014   }
2015 };
2016 
2017 class DeoptActionSerializer : public JfrSerializer {
2018  public:
2019   void serialize(JfrCheckpointWriter& writer) {
2020     static const u4 nof_actions = Deoptimization::Action_LIMIT;
2021     writer.write_count(nof_actions);
2022     for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
2023       writer.write_key(i);
2024       writer.write(Deoptimization::trap_action_name((int)i));
2025     }
2026   }
2027 };
2028 
2029 static void register_serializers() {
2030   static int critical_section = 0;
2031   if (1 == critical_section || Atomic::cmpxchg(&critical_section, 0, 1) == 1) {
2032     return;
2033   }
2034   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
2035   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
2036 }
2037 
2038 static void post_deoptimization_event(CompiledMethod* nm,
2039                                       const Method* method,
2040                                       int trap_bci,
2041                                       int instruction,
2042                                       Deoptimization::DeoptReason reason,
2043                                       Deoptimization::DeoptAction action) {
2044   assert(nm != nullptr, "invariant");
2045   assert(method != nullptr, "invariant");
2046   if (EventDeoptimization::is_enabled()) {
2047     static bool serializers_registered = false;
2048     if (!serializers_registered) {
2049       register_serializers();
2050       serializers_registered = true;
2051     }
2052     EventDeoptimization event;
2053     event.set_compileId(nm->compile_id());
2054     event.set_compiler(nm->compiler_type());
2055     event.set_method(method);
2056     event.set_lineNumber(method->line_number_from_bci(trap_bci));
2057     event.set_bci(trap_bci);
2058     event.set_instruction(instruction);
2059     event.set_reason(reason);
2060     event.set_action(action);
2061     event.commit();
2062   }
2063 }
2064 
2065 #endif // INCLUDE_JFR
2066 
2067 static void log_deopt(CompiledMethod* nm, Method* tm, intptr_t pc, frame& fr, int trap_bci,
2068                               const char* reason_name, const char* reason_action) {
2069   LogTarget(Debug, deoptimization) lt;
2070   if (lt.is_enabled()) {
2071     LogStream ls(lt);
2072     bool is_osr = nm->is_osr_method();
2073     ls.print("cid=%4d %s level=%d",
2074              nm->compile_id(), (is_osr ? "osr" : "   "), nm->comp_level());
2075     ls.print(" %s", tm->name_and_sig_as_C_string());
2076     ls.print(" trap_bci=%d ", trap_bci);
2077     if (is_osr) {
2078       ls.print("osr_bci=%d ", nm->osr_entry_bci());
2079     }
2080     ls.print("%s ", reason_name);
2081     ls.print("%s ", reason_action);
2082     ls.print_cr("pc=" INTPTR_FORMAT " relative_pc=" INTPTR_FORMAT,
2083              pc, fr.pc() - nm->code_begin());
2084   }
2085 }
2086 
2087 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
2088   HandleMark hm(current);
2089 
2090   // uncommon_trap() is called at the beginning of the uncommon trap
2091   // handler. Note this fact before we start generating temporary frames
2092   // that can confuse an asynchronous stack walker. This counter is
2093   // decremented at the end of unpack_frames().
2094 
2095   current->inc_in_deopt_handler();
2096 
2097 #if INCLUDE_JVMCI
2098   // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
2099   RegisterMap reg_map(current,
2100                       RegisterMap::UpdateMap::include,
2101                       RegisterMap::ProcessFrames::include,
2102                       RegisterMap::WalkContinuation::skip);
2103 #else
2104   RegisterMap reg_map(current,
2105                       RegisterMap::UpdateMap::skip,
2106                       RegisterMap::ProcessFrames::include,
2107                       RegisterMap::WalkContinuation::skip);
2108 #endif
2109   frame stub_frame = current->last_frame();
2110   frame fr = stub_frame.sender(&reg_map);
2111 
2112   // Log a message
2113   Events::log_deopt_message(current, "Uncommon trap: trap_request=" INT32_FORMAT_X_0 " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
2114               trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
2115 
2116   {
2117     ResourceMark rm;
2118 
2119     DeoptReason reason = trap_request_reason(trap_request);
2120     DeoptAction action = trap_request_action(trap_request);
2121 #if INCLUDE_JVMCI
2122     int debug_id = trap_request_debug_id(trap_request);
2123 #endif
2124     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
2125 
2126     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, current);
2127     compiledVFrame* cvf = compiledVFrame::cast(vf);
2128 
2129     CompiledMethod* nm = cvf->code();
2130 
2131     ScopeDesc*      trap_scope  = cvf->scope();
2132 
2133     bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
2134 
2135     if (is_receiver_constraint_failure) {
2136       tty->print_cr("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"),
2137                     trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
2138                     JVMCI_ONLY(COMMA debug_id));
2139     }
2140 
2141     methodHandle    trap_method(current, trap_scope->method());
2142     int             trap_bci    = trap_scope->bci();
2143 #if INCLUDE_JVMCI
2144     jlong           speculation = current->pending_failed_speculation();
2145     if (nm->is_compiled_by_jvmci()) {
2146       nm->as_nmethod()->update_speculation(current);
2147     } else {
2148       assert(speculation == 0, "There should not be a speculation for methods compiled by non-JVMCI compilers");
2149     }
2150 
2151     if (trap_bci == SynchronizationEntryBCI) {
2152       trap_bci = 0;
2153       current->set_pending_monitorenter(true);
2154     }
2155 
2156     if (reason == Deoptimization::Reason_transfer_to_interpreter) {
2157       current->set_pending_transfer_to_interpreter(true);
2158     }
2159 #endif
2160 
2161     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
2162     // Record this event in the histogram.
2163     gather_statistics(reason, action, trap_bc);
2164 
2165     // Ensure that we can record deopt. history:
2166     // Need MDO to record RTM code generation state.
2167     bool create_if_missing = ProfileTraps RTM_OPT_ONLY( || UseRTMLocking );
2168 
2169     methodHandle profiled_method;
2170 #if INCLUDE_JVMCI
2171     if (nm->is_compiled_by_jvmci()) {
2172       profiled_method = methodHandle(current, nm->method());
2173     } else {
2174       profiled_method = trap_method;
2175     }
2176 #else
2177     profiled_method = trap_method;
2178 #endif
2179 
2180     MethodData* trap_mdo =
2181       get_method_data(current, profiled_method, create_if_missing);
2182 
2183     { // Log Deoptimization event for JFR, UL and event system
2184       Method* tm = trap_method();
2185       const char* reason_name = trap_reason_name(reason);
2186       const char* reason_action = trap_action_name(action);
2187       intptr_t pc = p2i(fr.pc());
2188 
2189       JFR_ONLY(post_deoptimization_event(nm, tm, trap_bci, trap_bc, reason, action);)
2190       log_deopt(nm, tm, pc, fr, trap_bci, reason_name, reason_action);
2191       Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s",
2192                                 reason_name, reason_action, pc,
2193                                 tm->name_and_sig_as_C_string(), trap_bci, nm->compiler_name());
2194     }
2195 
2196     // Print a bunch of diagnostics, if requested.
2197     if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
2198       ResourceMark rm;
2199       ttyLocker ttyl;
2200       char buf[100];
2201       if (xtty != nullptr) {
2202         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT "' %s",
2203                          os::current_thread_id(),
2204                          format_trap_request(buf, sizeof(buf), trap_request));
2205 #if INCLUDE_JVMCI
2206         if (speculation != 0) {
2207           xtty->print(" speculation='" JLONG_FORMAT "'", speculation);
2208         }
2209 #endif
2210         nm->log_identity(xtty);
2211       }
2212       Symbol* class_name = nullptr;
2213       bool unresolved = false;
2214       if (unloaded_class_index >= 0) {
2215         constantPoolHandle constants (current, trap_method->constants());
2216         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
2217           class_name = constants->klass_name_at(unloaded_class_index);
2218           unresolved = true;
2219           if (xtty != nullptr)
2220             xtty->print(" unresolved='1'");
2221         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
2222           class_name = constants->symbol_at(unloaded_class_index);
2223         }
2224         if (xtty != nullptr)
2225           xtty->name(class_name);
2226       }
2227       if (xtty != nullptr && trap_mdo != nullptr && (int)reason < (int)MethodData::_trap_hist_limit) {
2228         // Dump the relevant MDO state.
2229         // This is the deopt count for the current reason, any previous
2230         // reasons or recompiles seen at this point.
2231         int dcnt = trap_mdo->trap_count(reason);
2232         if (dcnt != 0)
2233           xtty->print(" count='%d'", dcnt);
2234         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
2235         int dos = (pdata == nullptr)? 0: pdata->trap_state();
2236         if (dos != 0) {
2237           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
2238           if (trap_state_is_recompiled(dos)) {
2239             int recnt2 = trap_mdo->overflow_recompile_count();
2240             if (recnt2 != 0)
2241               xtty->print(" recompiles2='%d'", recnt2);
2242           }
2243         }
2244       }
2245       if (xtty != nullptr) {
2246         xtty->stamp();
2247         xtty->end_head();
2248       }
2249       if (TraceDeoptimization) {  // make noise on the tty
2250         stringStream st;
2251         st.print("UNCOMMON TRAP method=%s", trap_scope->method()->name_and_sig_as_C_string());
2252         st.print("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT JVMCI_ONLY(", debug_id=%d"),
2253                  trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin() JVMCI_ONLY(COMMA debug_id));
2254         st.print(" compiler=%s compile_id=%d", nm->compiler_name(), nm->compile_id());
2255 #if INCLUDE_JVMCI
2256         if (nm->is_nmethod()) {
2257           const char* installed_code_name = nm->as_nmethod()->jvmci_name();
2258           if (installed_code_name != nullptr) {
2259             st.print(" (JVMCI: installed code name=%s) ", installed_code_name);
2260           }
2261         }
2262 #endif
2263         st.print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
2264                    p2i(fr.pc()),
2265                    os::current_thread_id(),
2266                    trap_reason_name(reason),
2267                    trap_action_name(action),
2268                    unloaded_class_index
2269 #if INCLUDE_JVMCI
2270                    , debug_id
2271 #endif
2272                    );
2273         if (class_name != nullptr) {
2274           st.print(unresolved ? " unresolved class: " : " symbol: ");
2275           class_name->print_symbol_on(&st);
2276         }
2277         st.cr();
2278         tty->print_raw(st.freeze());
2279       }
2280       if (xtty != nullptr) {
2281         // Log the precise location of the trap.
2282         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2283           xtty->begin_elem("jvms bci='%d'", sd->bci());
2284           xtty->method(sd->method());
2285           xtty->end_elem();
2286           if (sd->is_top())  break;
2287         }
2288         xtty->tail("uncommon_trap");
2289       }
2290     }
2291     // (End diagnostic printout.)
2292 
2293     if (is_receiver_constraint_failure) {
2294       fatal("missing receiver type check");
2295     }
2296 
2297     // Load class if necessary
2298     if (unloaded_class_index >= 0) {
2299       constantPoolHandle constants(current, trap_method->constants());
2300       load_class_by_index(constants, unloaded_class_index, THREAD);
2301     }
2302 
2303     // Flush the nmethod if necessary and desirable.
2304     //
2305     // We need to avoid situations where we are re-flushing the nmethod
2306     // because of a hot deoptimization site.  Repeated flushes at the same
2307     // point need to be detected by the compiler and avoided.  If the compiler
2308     // cannot avoid them (or has a bug and "refuses" to avoid them), this
2309     // module must take measures to avoid an infinite cycle of recompilation
2310     // and deoptimization.  There are several such measures:
2311     //
2312     //   1. If a recompilation is ordered a second time at some site X
2313     //   and for the same reason R, the action is adjusted to 'reinterpret',
2314     //   to give the interpreter time to exercise the method more thoroughly.
2315     //   If this happens, the method's overflow_recompile_count is incremented.
2316     //
2317     //   2. If the compiler fails to reduce the deoptimization rate, then
2318     //   the method's overflow_recompile_count will begin to exceed the set
2319     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
2320     //   is adjusted to 'make_not_compilable', and the method is abandoned
2321     //   to the interpreter.  This is a performance hit for hot methods,
2322     //   but is better than a disastrous infinite cycle of recompilations.
2323     //   (Actually, only the method containing the site X is abandoned.)
2324     //
2325     //   3. In parallel with the previous measures, if the total number of
2326     //   recompilations of a method exceeds the much larger set limit
2327     //   PerMethodRecompilationCutoff, the method is abandoned.
2328     //   This should only happen if the method is very large and has
2329     //   many "lukewarm" deoptimizations.  The code which enforces this
2330     //   limit is elsewhere (class nmethod, class Method).
2331     //
2332     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2333     // to recompile at each bytecode independently of the per-BCI cutoff.
2334     //
2335     // The decision to update code is up to the compiler, and is encoded
2336     // in the Action_xxx code.  If the compiler requests Action_none
2337     // no trap state is changed, no compiled code is changed, and the
2338     // computation suffers along in the interpreter.
2339     //
2340     // The other action codes specify various tactics for decompilation
2341     // and recompilation.  Action_maybe_recompile is the loosest, and
2342     // allows the compiled code to stay around until enough traps are seen,
2343     // and until the compiler gets around to recompiling the trapping method.
2344     //
2345     // The other actions cause immediate removal of the present code.
2346 
2347     // Traps caused by injected profile shouldn't pollute trap counts.
2348     bool injected_profile_trap = trap_method->has_injected_profile() &&
2349                                  (reason == Reason_intrinsic || reason == Reason_unreached);
2350 
2351     bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2352     bool make_not_entrant = false;
2353     bool make_not_compilable = false;
2354     bool reprofile = false;
2355     switch (action) {
2356     case Action_none:
2357       // Keep the old code.
2358       update_trap_state = false;
2359       break;
2360     case Action_maybe_recompile:
2361       // Do not need to invalidate the present code, but we can
2362       // initiate another
2363       // Start compiler without (necessarily) invalidating the nmethod.
2364       // The system will tolerate the old code, but new code should be
2365       // generated when possible.
2366       break;
2367     case Action_reinterpret:
2368       // Go back into the interpreter for a while, and then consider
2369       // recompiling form scratch.
2370       make_not_entrant = true;
2371       // Reset invocation counter for outer most method.
2372       // This will allow the interpreter to exercise the bytecodes
2373       // for a while before recompiling.
2374       // By contrast, Action_make_not_entrant is immediate.
2375       //
2376       // Note that the compiler will track null_check, null_assert,
2377       // range_check, and class_check events and log them as if they
2378       // had been traps taken from compiled code.  This will update
2379       // the MDO trap history so that the next compilation will
2380       // properly detect hot trap sites.
2381       reprofile = true;
2382       break;
2383     case Action_make_not_entrant:
2384       // Request immediate recompilation, and get rid of the old code.
2385       // Make them not entrant, so next time they are called they get
2386       // recompiled.  Unloaded classes are loaded now so recompile before next
2387       // time they are called.  Same for uninitialized.  The interpreter will
2388       // link the missing class, if any.
2389       make_not_entrant = true;
2390       break;
2391     case Action_make_not_compilable:
2392       // Give up on compiling this method at all.
2393       make_not_entrant = true;
2394       make_not_compilable = true;
2395       break;
2396     default:
2397       ShouldNotReachHere();
2398     }
2399 
2400     // Setting +ProfileTraps fixes the following, on all platforms:
2401     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
2402     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2403     // recompile relies on a MethodData* to record heroic opt failures.
2404 
2405     // Whether the interpreter is producing MDO data or not, we also need
2406     // to use the MDO to detect hot deoptimization points and control
2407     // aggressive optimization.
2408     bool inc_recompile_count = false;
2409     ProfileData* pdata = nullptr;
2410     if (ProfileTraps && CompilerConfig::is_c2_or_jvmci_compiler_enabled() && update_trap_state && trap_mdo != nullptr) {
2411       assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2412       uint this_trap_count = 0;
2413       bool maybe_prior_trap = false;
2414       bool maybe_prior_recompile = false;
2415       pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
2416 #if INCLUDE_JVMCI
2417                                    nm->is_compiled_by_jvmci() && nm->is_osr_method(),
2418 #endif
2419                                    nm->method(),
2420                                    //outputs:
2421                                    this_trap_count,
2422                                    maybe_prior_trap,
2423                                    maybe_prior_recompile);
2424       // Because the interpreter also counts null, div0, range, and class
2425       // checks, these traps from compiled code are double-counted.
2426       // This is harmless; it just means that the PerXTrapLimit values
2427       // are in effect a little smaller than they look.
2428 
2429       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2430       if (per_bc_reason != Reason_none) {
2431         // Now take action based on the partially known per-BCI history.
2432         if (maybe_prior_trap
2433             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2434           // If there are too many traps at this BCI, force a recompile.
2435           // This will allow the compiler to see the limit overflow, and
2436           // take corrective action, if possible.  The compiler generally
2437           // does not use the exact PerBytecodeTrapLimit value, but instead
2438           // changes its tactics if it sees any traps at all.  This provides
2439           // a little hysteresis, delaying a recompile until a trap happens
2440           // several times.
2441           //
2442           // Actually, since there is only one bit of counter per BCI,
2443           // the possible per-BCI counts are {0,1,(per-method count)}.
2444           // This produces accurate results if in fact there is only
2445           // one hot trap site, but begins to get fuzzy if there are
2446           // many sites.  For example, if there are ten sites each
2447           // trapping two or more times, they each get the blame for
2448           // all of their traps.
2449           make_not_entrant = true;
2450         }
2451 
2452         // Detect repeated recompilation at the same BCI, and enforce a limit.
2453         if (make_not_entrant && maybe_prior_recompile) {
2454           // More than one recompile at this point.
2455           inc_recompile_count = maybe_prior_trap;
2456         }
2457       } else {
2458         // For reasons which are not recorded per-bytecode, we simply
2459         // force recompiles unconditionally.
2460         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2461         make_not_entrant = true;
2462       }
2463 
2464       // Go back to the compiler if there are too many traps in this method.
2465       if (this_trap_count >= per_method_trap_limit(reason)) {
2466         // If there are too many traps in this method, force a recompile.
2467         // This will allow the compiler to see the limit overflow, and
2468         // take corrective action, if possible.
2469         // (This condition is an unlikely backstop only, because the
2470         // PerBytecodeTrapLimit is more likely to take effect first,
2471         // if it is applicable.)
2472         make_not_entrant = true;
2473       }
2474 
2475       // Here's more hysteresis:  If there has been a recompile at
2476       // this trap point already, run the method in the interpreter
2477       // for a while to exercise it more thoroughly.
2478       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2479         reprofile = true;
2480       }
2481     }
2482 
2483     // Take requested actions on the method:
2484 
2485     // Recompile
2486     if (make_not_entrant) {
2487       if (!nm->make_not_entrant()) {
2488         return; // the call did not change nmethod's state
2489       }
2490 
2491       if (pdata != nullptr) {
2492         // Record the recompilation event, if any.
2493         int tstate0 = pdata->trap_state();
2494         int tstate1 = trap_state_set_recompiled(tstate0, true);
2495         if (tstate1 != tstate0)
2496           pdata->set_trap_state(tstate1);
2497       }
2498 
2499 #if INCLUDE_RTM_OPT
2500       // Restart collecting RTM locking abort statistic if the method
2501       // is recompiled for a reason other than RTM state change.
2502       // Assume that in new recompiled code the statistic could be different,
2503       // for example, due to different inlining.
2504       if ((reason != Reason_rtm_state_change) && (trap_mdo != nullptr) &&
2505           UseRTMDeopt && (nm->as_nmethod()->rtm_state() != ProfileRTM)) {
2506         trap_mdo->atomic_set_rtm_state(ProfileRTM);
2507       }
2508 #endif
2509       // For code aging we count traps separately here, using make_not_entrant()
2510       // as a guard against simultaneous deopts in multiple threads.
2511       if (reason == Reason_tenured && trap_mdo != nullptr) {
2512         trap_mdo->inc_tenure_traps();
2513       }
2514     }
2515 
2516     if (inc_recompile_count) {
2517       trap_mdo->inc_overflow_recompile_count();
2518       if ((uint)trap_mdo->overflow_recompile_count() >
2519           (uint)PerBytecodeRecompilationCutoff) {
2520         // Give up on the method containing the bad BCI.
2521         if (trap_method() == nm->method()) {
2522           make_not_compilable = true;
2523         } else {
2524           trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2525           // But give grace to the enclosing nm->method().
2526         }
2527       }
2528     }
2529 
2530     // Reprofile
2531     if (reprofile) {
2532       CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2533     }
2534 
2535     // Give up compiling
2536     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2537       assert(make_not_entrant, "consistent");
2538       nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2539     }
2540 
2541   } // Free marked resources
2542 
2543 }
2544 JRT_END
2545 
2546 ProfileData*
2547 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2548                                          int trap_bci,
2549                                          Deoptimization::DeoptReason reason,
2550                                          bool update_total_trap_count,
2551 #if INCLUDE_JVMCI
2552                                          bool is_osr,
2553 #endif
2554                                          Method* compiled_method,
2555                                          //outputs:
2556                                          uint& ret_this_trap_count,
2557                                          bool& ret_maybe_prior_trap,
2558                                          bool& ret_maybe_prior_recompile) {
2559   bool maybe_prior_trap = false;
2560   bool maybe_prior_recompile = false;
2561   uint this_trap_count = 0;
2562   if (update_total_trap_count) {
2563     uint idx = reason;
2564 #if INCLUDE_JVMCI
2565     if (is_osr) {
2566       // Upper half of history array used for traps in OSR compilations
2567       idx += Reason_TRAP_HISTORY_LENGTH;
2568     }
2569 #endif
2570     uint prior_trap_count = trap_mdo->trap_count(idx);
2571     this_trap_count  = trap_mdo->inc_trap_count(idx);
2572 
2573     // If the runtime cannot find a place to store trap history,
2574     // it is estimated based on the general condition of the method.
2575     // If the method has ever been recompiled, or has ever incurred
2576     // a trap with the present reason , then this BCI is assumed
2577     // (pessimistically) to be the culprit.
2578     maybe_prior_trap      = (prior_trap_count != 0);
2579     maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2580   }
2581   ProfileData* pdata = nullptr;
2582 
2583 
2584   // For reasons which are recorded per bytecode, we check per-BCI data.
2585   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2586   assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
2587   if (per_bc_reason != Reason_none) {
2588     // Find the profile data for this BCI.  If there isn't one,
2589     // try to allocate one from the MDO's set of spares.
2590     // This will let us detect a repeated trap at this point.
2591     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : nullptr);
2592 
2593     if (pdata != nullptr) {
2594       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2595         if (LogCompilation && xtty != nullptr) {
2596           ttyLocker ttyl;
2597           // no more room for speculative traps in this MDO
2598           xtty->elem("speculative_traps_oom");
2599         }
2600       }
2601       // Query the trap state of this profile datum.
2602       int tstate0 = pdata->trap_state();
2603       if (!trap_state_has_reason(tstate0, per_bc_reason))
2604         maybe_prior_trap = false;
2605       if (!trap_state_is_recompiled(tstate0))
2606         maybe_prior_recompile = false;
2607 
2608       // Update the trap state of this profile datum.
2609       int tstate1 = tstate0;
2610       // Record the reason.
2611       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2612       // Store the updated state on the MDO, for next time.
2613       if (tstate1 != tstate0)
2614         pdata->set_trap_state(tstate1);
2615     } else {
2616       if (LogCompilation && xtty != nullptr) {
2617         ttyLocker ttyl;
2618         // Missing MDP?  Leave a small complaint in the log.
2619         xtty->elem("missing_mdp bci='%d'", trap_bci);
2620       }
2621     }
2622   }
2623 
2624   // Return results:
2625   ret_this_trap_count = this_trap_count;
2626   ret_maybe_prior_trap = maybe_prior_trap;
2627   ret_maybe_prior_recompile = maybe_prior_recompile;
2628   return pdata;
2629 }
2630 
2631 void
2632 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2633   ResourceMark rm;
2634   // Ignored outputs:
2635   uint ignore_this_trap_count;
2636   bool ignore_maybe_prior_trap;
2637   bool ignore_maybe_prior_recompile;
2638   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2639   // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2640   bool update_total_counts = true JVMCI_ONLY( && !UseJVMCICompiler);
2641   query_update_method_data(trap_mdo, trap_bci,
2642                            (DeoptReason)reason,
2643                            update_total_counts,
2644 #if INCLUDE_JVMCI
2645                            false,
2646 #endif
2647                            nullptr,
2648                            ignore_this_trap_count,
2649                            ignore_maybe_prior_trap,
2650                            ignore_maybe_prior_recompile);
2651 }
2652 
2653 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode) {
2654   // Enable WXWrite: current function is called from methods compiled by C2 directly
2655   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2656 
2657   // Still in Java no safepoints
2658   {
2659     // This enters VM and may safepoint
2660     uncommon_trap_inner(current, trap_request);
2661   }
2662   HandleMark hm(current);
2663   return fetch_unroll_info_helper(current, exec_mode);
2664 }
2665 
2666 // Local derived constants.
2667 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2668 const int DS_REASON_MASK   = ((uint)DataLayout::trap_mask) >> 1;
2669 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2670 
2671 //---------------------------trap_state_reason---------------------------------
2672 Deoptimization::DeoptReason
2673 Deoptimization::trap_state_reason(int trap_state) {
2674   // This assert provides the link between the width of DataLayout::trap_bits
2675   // and the encoding of "recorded" reasons.  It ensures there are enough
2676   // bits to store all needed reasons in the per-BCI MDO profile.
2677   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2678   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2679   trap_state -= recompile_bit;
2680   if (trap_state == DS_REASON_MASK) {
2681     return Reason_many;
2682   } else {
2683     assert((int)Reason_none == 0, "state=0 => Reason_none");
2684     return (DeoptReason)trap_state;
2685   }
2686 }
2687 //-------------------------trap_state_has_reason-------------------------------
2688 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2689   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2690   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2691   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2692   trap_state -= recompile_bit;
2693   if (trap_state == DS_REASON_MASK) {
2694     return -1;  // true, unspecifically (bottom of state lattice)
2695   } else if (trap_state == reason) {
2696     return 1;   // true, definitely
2697   } else if (trap_state == 0) {
2698     return 0;   // false, definitely (top of state lattice)
2699   } else {
2700     return 0;   // false, definitely
2701   }
2702 }
2703 //-------------------------trap_state_add_reason-------------------------------
2704 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2705   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2706   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2707   trap_state -= recompile_bit;
2708   if (trap_state == DS_REASON_MASK) {
2709     return trap_state + recompile_bit;     // already at state lattice bottom
2710   } else if (trap_state == reason) {
2711     return trap_state + recompile_bit;     // the condition is already true
2712   } else if (trap_state == 0) {
2713     return reason + recompile_bit;          // no condition has yet been true
2714   } else {
2715     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
2716   }
2717 }
2718 //-----------------------trap_state_is_recompiled------------------------------
2719 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2720   return (trap_state & DS_RECOMPILE_BIT) != 0;
2721 }
2722 //-----------------------trap_state_set_recompiled-----------------------------
2723 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2724   if (z)  return trap_state |  DS_RECOMPILE_BIT;
2725   else    return trap_state & ~DS_RECOMPILE_BIT;
2726 }
2727 //---------------------------format_trap_state---------------------------------
2728 // This is used for debugging and diagnostics, including LogFile output.
2729 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2730                                               int trap_state) {
2731   assert(buflen > 0, "sanity");
2732   DeoptReason reason      = trap_state_reason(trap_state);
2733   bool        recomp_flag = trap_state_is_recompiled(trap_state);
2734   // Re-encode the state from its decoded components.
2735   int decoded_state = 0;
2736   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2737     decoded_state = trap_state_add_reason(decoded_state, reason);
2738   if (recomp_flag)
2739     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2740   // If the state re-encodes properly, format it symbolically.
2741   // Because this routine is used for debugging and diagnostics,
2742   // be robust even if the state is a strange value.
2743   size_t len;
2744   if (decoded_state != trap_state) {
2745     // Random buggy state that doesn't decode??
2746     len = jio_snprintf(buf, buflen, "#%d", trap_state);
2747   } else {
2748     len = jio_snprintf(buf, buflen, "%s%s",
2749                        trap_reason_name(reason),
2750                        recomp_flag ? " recompiled" : "");
2751   }
2752   return buf;
2753 }
2754 
2755 
2756 //--------------------------------statics--------------------------------------
2757 const char* Deoptimization::_trap_reason_name[] = {
2758   // Note:  Keep this in sync. with enum DeoptReason.
2759   "none",
2760   "null_check",
2761   "null_assert" JVMCI_ONLY("_or_unreached0"),
2762   "range_check",
2763   "class_check",
2764   "array_check",
2765   "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2766   "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2767   "profile_predicate",
2768   "unloaded",
2769   "uninitialized",
2770   "initialized",
2771   "unreached",
2772   "unhandled",
2773   "constraint",
2774   "div0_check",
2775   "age",
2776   "predicate",
2777   "loop_limit_check",
2778   "speculate_class_check",
2779   "speculate_null_check",
2780   "speculate_null_assert",
2781   "rtm_state_change",
2782   "unstable_if",
2783   "unstable_fused_if",
2784   "receiver_constraint",
2785 #if INCLUDE_JVMCI
2786   "aliasing",
2787   "transfer_to_interpreter",
2788   "not_compiled_exception_handler",
2789   "unresolved",
2790   "jsr_mismatch",
2791 #endif
2792   "tenured"
2793 };
2794 const char* Deoptimization::_trap_action_name[] = {
2795   // Note:  Keep this in sync. with enum DeoptAction.
2796   "none",
2797   "maybe_recompile",
2798   "reinterpret",
2799   "make_not_entrant",
2800   "make_not_compilable"
2801 };
2802 
2803 const char* Deoptimization::trap_reason_name(int reason) {
2804   // Check that every reason has a name
2805   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2806 
2807   if (reason == Reason_many)  return "many";
2808   if ((uint)reason < Reason_LIMIT)
2809     return _trap_reason_name[reason];
2810   static char buf[20];
2811   os::snprintf_checked(buf, sizeof(buf), "reason%d", reason);
2812   return buf;
2813 }
2814 const char* Deoptimization::trap_action_name(int action) {
2815   // Check that every action has a name
2816   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2817 
2818   if ((uint)action < Action_LIMIT)
2819     return _trap_action_name[action];
2820   static char buf[20];
2821   os::snprintf_checked(buf, sizeof(buf), "action%d", action);
2822   return buf;
2823 }
2824 
2825 // This is used for debugging and diagnostics, including LogFile output.
2826 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2827                                                 int trap_request) {
2828   jint unloaded_class_index = trap_request_index(trap_request);
2829   const char* reason = trap_reason_name(trap_request_reason(trap_request));
2830   const char* action = trap_action_name(trap_request_action(trap_request));
2831 #if INCLUDE_JVMCI
2832   int debug_id = trap_request_debug_id(trap_request);
2833 #endif
2834   size_t len;
2835   if (unloaded_class_index < 0) {
2836     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2837                        reason, action
2838 #if INCLUDE_JVMCI
2839                        ,debug_id
2840 #endif
2841                        );
2842   } else {
2843     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2844                        reason, action, unloaded_class_index
2845 #if INCLUDE_JVMCI
2846                        ,debug_id
2847 #endif
2848                        );
2849   }
2850   return buf;
2851 }
2852 
2853 juint Deoptimization::_deoptimization_hist
2854         [Deoptimization::Reason_LIMIT]
2855     [1 + Deoptimization::Action_LIMIT]
2856         [Deoptimization::BC_CASE_LIMIT]
2857   = {0};
2858 
2859 enum {
2860   LSB_BITS = 8,
2861   LSB_MASK = right_n_bits(LSB_BITS)
2862 };
2863 
2864 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2865                                        Bytecodes::Code bc) {
2866   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2867   assert(action >= 0 && action < Action_LIMIT, "oob");
2868   _deoptimization_hist[Reason_none][0][0] += 1;  // total
2869   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
2870   juint* cases = _deoptimization_hist[reason][1+action];
2871   juint* bc_counter_addr = nullptr;
2872   juint  bc_counter      = 0;
2873   // Look for an unused counter, or an exact match to this BC.
2874   if (bc != Bytecodes::_illegal) {
2875     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2876       juint* counter_addr = &cases[bc_case];
2877       juint  counter = *counter_addr;
2878       if ((counter == 0 && bc_counter_addr == nullptr)
2879           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2880         // this counter is either free or is already devoted to this BC
2881         bc_counter_addr = counter_addr;
2882         bc_counter = counter | bc;
2883       }
2884     }
2885   }
2886   if (bc_counter_addr == nullptr) {
2887     // Overflow, or no given bytecode.
2888     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2889     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
2890   }
2891   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2892 }
2893 
2894 jint Deoptimization::total_deoptimization_count() {
2895   return _deoptimization_hist[Reason_none][0][0];
2896 }
2897 
2898 // Get the deopt count for a specific reason and a specific action. If either
2899 // one of 'reason' or 'action' is null, the method returns the sum of all
2900 // deoptimizations with the specific 'action' or 'reason' respectively.
2901 // If both arguments are null, the method returns the total deopt count.
2902 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2903   if (reason_str == nullptr && action_str == nullptr) {
2904     return total_deoptimization_count();
2905   }
2906   juint counter = 0;
2907   for (int reason = 0; reason < Reason_LIMIT; reason++) {
2908     if (reason_str == nullptr || !strcmp(reason_str, trap_reason_name(reason))) {
2909       for (int action = 0; action < Action_LIMIT; action++) {
2910         if (action_str == nullptr || !strcmp(action_str, trap_action_name(action))) {
2911           juint* cases = _deoptimization_hist[reason][1+action];
2912           for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2913             counter += cases[bc_case] >> LSB_BITS;
2914           }
2915         }
2916       }
2917     }
2918   }
2919   return counter;
2920 }
2921 
2922 void Deoptimization::print_statistics() {
2923   juint total = total_deoptimization_count();
2924   juint account = total;
2925   if (total != 0) {
2926     ttyLocker ttyl;
2927     if (xtty != nullptr)  xtty->head("statistics type='deoptimization'");
2928     tty->print_cr("Deoptimization traps recorded:");
2929     #define PRINT_STAT_LINE(name, r) \
2930       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2931     PRINT_STAT_LINE("total", total);
2932     // For each non-zero entry in the histogram, print the reason,
2933     // the action, and (if specifically known) the type of bytecode.
2934     for (int reason = 0; reason < Reason_LIMIT; reason++) {
2935       for (int action = 0; action < Action_LIMIT; action++) {
2936         juint* cases = _deoptimization_hist[reason][1+action];
2937         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2938           juint counter = cases[bc_case];
2939           if (counter != 0) {
2940             char name[1*K];
2941             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2942             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2943               bc = Bytecodes::_illegal;
2944             os::snprintf_checked(name, sizeof(name), "%s/%s/%s",
2945                     trap_reason_name(reason),
2946                     trap_action_name(action),
2947                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2948             juint r = counter >> LSB_BITS;
2949             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2950             account -= r;
2951           }
2952         }
2953       }
2954     }
2955     if (account != 0) {
2956       PRINT_STAT_LINE("unaccounted", account);
2957     }
2958     #undef PRINT_STAT_LINE
2959     if (xtty != nullptr)  xtty->tail("statistics");
2960   }
2961 }
2962 
2963 #else // COMPILER2_OR_JVMCI
2964 
2965 
2966 // Stubs for C1 only system.
2967 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2968   return false;
2969 }
2970 
2971 const char* Deoptimization::trap_reason_name(int reason) {
2972   return "unknown";
2973 }
2974 
2975 jint Deoptimization::total_deoptimization_count() {
2976   return 0;
2977 }
2978 
2979 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2980   return 0;
2981 }
2982 
2983 void Deoptimization::print_statistics() {
2984   // no output
2985 }
2986 
2987 void
2988 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2989   // no update
2990 }
2991 
2992 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2993   return 0;
2994 }
2995 
2996 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2997                                        Bytecodes::Code bc) {
2998   // no update
2999 }
3000 
3001 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
3002                                               int trap_state) {
3003   jio_snprintf(buf, buflen, "#%d", trap_state);
3004   return buf;
3005 }
3006 
3007 #endif // COMPILER2_OR_JVMCI