1 /*
   2  * Copyright (c) 1997, 2025, 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 "classfile/javaClasses.inline.hpp"
  26 #include "classfile/symbolTable.hpp"
  27 #include "classfile/systemDictionary.hpp"
  28 #include "classfile/vmClasses.hpp"
  29 #include "code/codeCache.hpp"
  30 #include "code/debugInfoRec.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "code/pcDesc.hpp"
  33 #include "code/scopeDesc.hpp"
  34 #include "compiler/compilationPolicy.hpp"
  35 #include "compiler/compilerDefinitions.inline.hpp"
  36 #include "gc/shared/collectedHeap.hpp"
  37 #include "gc/shared/memAllocator.hpp"
  38 #include "interpreter/bytecode.inline.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/fieldStreams.inline.hpp"
  53 #include "oops/method.hpp"
  54 #include "oops/objArrayKlass.hpp"
  55 #include "oops/objArrayOop.inline.hpp"
  56 #include "oops/oop.inline.hpp"
  57 #include "oops/typeArrayOop.inline.hpp"
  58 #include "oops/verifyOopClosure.hpp"
  59 #include "prims/jvmtiDeferredUpdates.hpp"
  60 #include "prims/jvmtiExport.hpp"
  61 #include "prims/jvmtiThreadState.hpp"
  62 #include "prims/methodHandles.hpp"
  63 #include "prims/vectorSupport.hpp"
  64 #include "runtime/atomicAccess.hpp"
  65 #include "runtime/basicLock.inline.hpp"
  66 #include "runtime/continuation.hpp"
  67 #include "runtime/continuationEntry.inline.hpp"
  68 #include "runtime/deoptimization.hpp"
  69 #include "runtime/escapeBarrier.hpp"
  70 #include "runtime/fieldDescriptor.inline.hpp"
  71 #include "runtime/frame.inline.hpp"
  72 #include "runtime/handles.inline.hpp"
  73 #include "runtime/interfaceSupport.inline.hpp"
  74 #include "runtime/javaThread.hpp"
  75 #include "runtime/jniHandles.inline.hpp"
  76 #include "runtime/keepStackGCProcessed.hpp"
  77 #include "runtime/lightweightSynchronizer.hpp"
  78 #include "runtime/lockStack.inline.hpp"
  79 #include "runtime/objectMonitor.inline.hpp"
  80 #include "runtime/osThread.hpp"
  81 #include "runtime/perfData.inline.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.inline.hpp"
  90 #include "runtime/threadSMR.hpp"
  91 #include "runtime/threadWXSetters.inline.hpp"
  92 #include "runtime/vframe.hpp"
  93 #include "runtime/vframe_hp.hpp"
  94 #include "runtime/vframeArray.hpp"
  95 #include "runtime/vmOperations.hpp"
  96 #include "services/management.hpp"
  97 #include "utilities/checkedCast.hpp"
  98 #include "utilities/events.hpp"
  99 #include "utilities/growableArray.hpp"
 100 #include "utilities/macros.hpp"
 101 #include "utilities/preserveException.hpp"
 102 #include "utilities/xmlstream.hpp"
 103 #if INCLUDE_JFR
 104 #include "jfr/jfr.inline.hpp"
 105 #include "jfr/jfrEvents.hpp"
 106 #include "jfr/metadata/jfrSerializer.hpp"
 107 #endif
 108 
 109 uint64_t DeoptimizationScope::_committed_deopt_gen = 0;
 110 uint64_t DeoptimizationScope::_active_deopt_gen    = 1;
 111 bool     DeoptimizationScope::_committing_in_progress = false;
 112 
 113 DeoptimizationScope::DeoptimizationScope() : _required_gen(0) {
 114   DEBUG_ONLY(_deopted = false;)
 115 
 116   MutexLocker ml(NMethodState_lock, Mutex::_no_safepoint_check_flag);
 117   // If there is nothing to deopt _required_gen is the same as comitted.
 118   _required_gen = DeoptimizationScope::_committed_deopt_gen;
 119 }
 120 
 121 DeoptimizationScope::~DeoptimizationScope() {
 122   assert(_deopted, "Deopt not executed");
 123 }
 124 
 125 void DeoptimizationScope::mark(nmethod* nm, bool inc_recompile_counts) {
 126   if (!nm->can_be_deoptimized()) {
 127     return;
 128   }
 129 
 130   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 131 
 132   // If it's already marked but we still need it to be deopted.
 133   if (nm->is_marked_for_deoptimization()) {
 134     dependent(nm);
 135     return;
 136   }
 137 
 138   nmethod::DeoptimizationStatus status =
 139     inc_recompile_counts ? nmethod::deoptimize : nmethod::deoptimize_noupdate;
 140   AtomicAccess::store(&nm->_deoptimization_status, status);
 141 
 142   // Make sure active is not committed
 143   assert(DeoptimizationScope::_committed_deopt_gen < DeoptimizationScope::_active_deopt_gen, "Must be");
 144   assert(nm->_deoptimization_generation == 0, "Is already marked");
 145 
 146   nm->_deoptimization_generation = DeoptimizationScope::_active_deopt_gen;
 147   _required_gen                  = DeoptimizationScope::_active_deopt_gen;
 148 }
 149 
 150 void DeoptimizationScope::dependent(nmethod* nm) {
 151   ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 152 
 153   // A method marked by someone else may have a _required_gen lower than what we marked with.
 154   // Therefore only store it if it's higher than _required_gen.
 155   if (_required_gen < nm->_deoptimization_generation) {
 156     _required_gen = nm->_deoptimization_generation;
 157   }
 158 }
 159 
 160 void DeoptimizationScope::deoptimize_marked() {
 161   assert(!_deopted, "Already deopted");
 162 
 163   // We are not alive yet.
 164   if (!Universe::is_fully_initialized()) {
 165     DEBUG_ONLY(_deopted = true;)
 166     return;
 167   }
 168 
 169   // Safepoints are a special case, handled here.
 170   if (SafepointSynchronize::is_at_safepoint()) {
 171     DeoptimizationScope::_committed_deopt_gen = DeoptimizationScope::_active_deopt_gen;
 172     DeoptimizationScope::_active_deopt_gen++;
 173     Deoptimization::deoptimize_all_marked();
 174     DEBUG_ONLY(_deopted = true;)
 175     return;
 176   }
 177 
 178   uint64_t comitting = 0;
 179   bool wait = false;
 180   while (true) {
 181     {
 182       ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 183 
 184       // First we check if we or someone else already deopted the gen we want.
 185       if (DeoptimizationScope::_committed_deopt_gen >= _required_gen) {
 186         DEBUG_ONLY(_deopted = true;)
 187         return;
 188       }
 189       if (!_committing_in_progress) {
 190         // The version we are about to commit.
 191         comitting = DeoptimizationScope::_active_deopt_gen;
 192         // Make sure new marks use a higher gen.
 193         DeoptimizationScope::_active_deopt_gen++;
 194         _committing_in_progress = true;
 195         wait = false;
 196       } else {
 197         // Another thread is handshaking and committing a gen.
 198         wait = true;
 199       }
 200     }
 201     if (wait) {
 202       // Wait and let the concurrent handshake be performed.
 203       ThreadBlockInVM tbivm(JavaThread::current());
 204       os::naked_yield();
 205     } else {
 206       // Performs the handshake.
 207       Deoptimization::deoptimize_all_marked(); // May safepoint and an additional deopt may have occurred.
 208       DEBUG_ONLY(_deopted = true;)
 209       {
 210         ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
 211 
 212         // Make sure that committed doesn't go backwards.
 213         // Should only happen if we did a deopt during a safepoint above.
 214         if (DeoptimizationScope::_committed_deopt_gen < comitting) {
 215           DeoptimizationScope::_committed_deopt_gen = comitting;
 216         }
 217         _committing_in_progress = false;
 218 
 219         assert(DeoptimizationScope::_committed_deopt_gen >= _required_gen, "Must be");
 220 
 221         return;
 222       }
 223     }
 224   }
 225 }
 226 
 227 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
 228                                          int  caller_adjustment,
 229                                          int  caller_actual_parameters,
 230                                          int  number_of_frames,
 231                                          intptr_t* frame_sizes,
 232                                          address* frame_pcs,
 233                                          BasicType return_type,
 234                                          int exec_mode) {
 235   _size_of_deoptimized_frame = size_of_deoptimized_frame;
 236   _caller_adjustment         = caller_adjustment;
 237   _caller_actual_parameters  = caller_actual_parameters;
 238   _number_of_frames          = number_of_frames;
 239   _frame_sizes               = frame_sizes;
 240   _frame_pcs                 = frame_pcs;
 241   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
 242   _return_type               = return_type;
 243   _initial_info              = 0;
 244   // PD (x86 only)
 245   _counter_temp              = 0;
 246   _unpack_kind               = exec_mode;
 247   _sender_sp_temp            = 0;
 248 
 249   _total_frame_sizes         = size_of_frames();
 250   assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
 251 }
 252 
 253 Deoptimization::UnrollBlock::~UnrollBlock() {
 254   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
 255   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
 256   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
 257 }
 258 
 259 int Deoptimization::UnrollBlock::size_of_frames() const {
 260   // Account first for the adjustment of the initial frame
 261   intptr_t result = _caller_adjustment;
 262   for (int index = 0; index < number_of_frames(); index++) {
 263     result += frame_sizes()[index];
 264   }
 265   return checked_cast<int>(result);
 266 }
 267 
 268 void Deoptimization::UnrollBlock::print() {
 269   ResourceMark rm;
 270   stringStream st;
 271   st.print_cr("UnrollBlock");
 272   st.print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 273   st.print(   "  frame_sizes: ");
 274   for (int index = 0; index < number_of_frames(); index++) {
 275     st.print("%zd ", frame_sizes()[index]);
 276   }
 277   st.cr();
 278   tty->print_raw(st.freeze());
 279 }
 280 
 281 // In order to make fetch_unroll_info work properly with escape
 282 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
 283 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
 284 // which is called from the method fetch_unroll_info_helper below.
 285 JRT_BLOCK_ENTRY_PROF(Deoptimization::UnrollBlock*, Deoptimization, fetch_unroll_info, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
 286   // fetch_unroll_info() is called at the beginning of the deoptimization
 287   // handler. Note this fact before we start generating temporary frames
 288   // that can confuse an asynchronous stack walker. This counter is
 289   // decremented at the end of unpack_frames().
 290   current->inc_in_deopt_handler();
 291 
 292   if (exec_mode == Unpack_exception) {
 293     // When we get here, a callee has thrown an exception into a deoptimized
 294     // frame. That throw might have deferred stack watermark checking until
 295     // after unwinding. So we deal with such deferred requests here.
 296     StackWatermarkSet::after_unwind(current);
 297   }
 298 
 299   return fetch_unroll_info_helper(current, exec_mode);
 300 JRT_END
 301 
 302 #if COMPILER2_OR_JVMCI
 303 // print information about reallocated objects
 304 static void print_objects(JavaThread* deoptee_thread,
 305                           GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
 306   ResourceMark rm;
 307   stringStream st;  // change to logStream with logging
 308   st.print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
 309   fieldDescriptor fd;
 310 
 311   for (int i = 0; i < objects->length(); i++) {
 312     ObjectValue* sv = (ObjectValue*) objects->at(i);
 313     Handle obj = sv->value();
 314 
 315     if (obj.is_null()) {
 316       st.print_cr("     nullptr");
 317       continue;
 318     }
 319 
 320     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
 321 
 322     st.print("     object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
 323     k->print_value_on(&st);
 324     st.print_cr(" allocated (%zu bytes)", obj->size() * HeapWordSize);
 325 
 326     if (Verbose && k != nullptr) {
 327       k->oop_print_on(obj(), &st);
 328     }
 329   }
 330   tty->print_raw(st.freeze());
 331 }
 332 
 333 static bool rematerialize_objects(JavaThread* thread, int exec_mode, nmethod* compiled_method,
 334                                   frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
 335                                   bool& deoptimized_objects) {
 336   bool realloc_failures = false;
 337   assert (chunk->at(0)->scope() != nullptr,"expect only compiled java frames");
 338 
 339   JavaThread* deoptee_thread = chunk->at(0)->thread();
 340   assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
 341          "a frame can only be deoptimized by the owner thread");
 342 
 343   GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects_to_rematerialize(deoptee, map);
 344 
 345   // The flag return_oop() indicates call sites which return oop
 346   // in compiled code. Such sites include java method calls,
 347   // runtime calls (for example, used to allocate new objects/arrays
 348   // on slow code path) and any other calls generated in compiled code.
 349   // It is not guaranteed that we can get such information here only
 350   // by analyzing bytecode in deoptimized frames. This is why this flag
 351   // is set during method compilation (see Compile::Process_OopMap_Node()).
 352   // If the previous frame was popped or if we are dispatching an exception,
 353   // we don't have an oop result.
 354   bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt);
 355   Handle return_value;
 356   if (save_oop_result) {
 357     // Reallocation may trigger GC. If deoptimization happened on return from
 358     // call which returns oop we need to save it since it is not in oopmap.
 359     oop result = deoptee.saved_oop_result(&map);
 360     assert(oopDesc::is_oop_or_null(result), "must be oop");
 361     return_value = Handle(thread, result);
 362     assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 363     if (TraceDeoptimization) {
 364       tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
 365       tty->cr();
 366     }
 367   }
 368   if (objects != nullptr) {
 369     if (exec_mode == Deoptimization::Unpack_none) {
 370       assert(thread->thread_state() == _thread_in_vm, "assumption");
 371       JavaThread* THREAD = thread; // For exception macros.
 372       // Clear pending OOM if reallocation fails and return true indicating allocation failure
 373       realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
 374       deoptimized_objects = true;
 375     } else {
 376       JavaThread* current = thread; // For JRT_BLOCK
 377       JRT_BLOCK
 378       realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
 379       JRT_END
 380     }
 381     guarantee(compiled_method != nullptr, "deopt must be associated with an nmethod");
 382     bool is_jvmci = compiled_method->is_compiled_by_jvmci();
 383     Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, is_jvmci);
 384     if (TraceDeoptimization) {
 385       print_objects(deoptee_thread, objects, realloc_failures);
 386     }
 387   }
 388   if (save_oop_result) {
 389     // Restore result.
 390     deoptee.set_saved_oop_result(&map, return_value());
 391   }
 392   return realloc_failures;
 393 }
 394 
 395 static void restore_eliminated_locks(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures,
 396                                      frame& deoptee, int exec_mode, bool& deoptimized_objects) {
 397   JavaThread* deoptee_thread = chunk->at(0)->thread();
 398   assert(!EscapeBarrier::objs_are_deoptimized(deoptee_thread, deoptee.id()), "must relock just once");
 399   assert(thread == Thread::current(), "should be");
 400   HandleMark hm(thread);
 401 #ifndef PRODUCT
 402   bool first = true;
 403 #endif // !PRODUCT
 404   // Start locking from outermost/oldest frame
 405   for (int i = (chunk->length() - 1); i >= 0; i--) {
 406     compiledVFrame* cvf = chunk->at(i);
 407     assert (cvf->scope() != nullptr,"expect only compiled java frames");
 408     GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 409     if (monitors->is_nonempty()) {
 410       bool relocked = Deoptimization::relock_objects(thread, monitors, deoptee_thread, deoptee,
 411                                                      exec_mode, realloc_failures);
 412       deoptimized_objects = deoptimized_objects || relocked;
 413 #ifndef PRODUCT
 414       if (PrintDeoptimizationDetails) {
 415         ResourceMark rm;
 416         stringStream st;
 417         for (int j = 0; j < monitors->length(); j++) {
 418           MonitorInfo* mi = monitors->at(j);
 419           if (mi->eliminated()) {
 420             if (first) {
 421               first = false;
 422               st.print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 423             }
 424             if (exec_mode == Deoptimization::Unpack_none) {
 425               ObjectMonitor* monitor = deoptee_thread->current_waiting_monitor();
 426               if (monitor != nullptr && monitor->object() == mi->owner()) {
 427                 st.print_cr("     object <" INTPTR_FORMAT "> DEFERRED relocking after wait", p2i(mi->owner()));
 428                 continue;
 429               }
 430             }
 431             if (mi->owner_is_scalar_replaced()) {
 432               Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
 433               st.print_cr("     failed reallocation for klass %s", k->external_name());
 434             } else {
 435               st.print_cr("     object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
 436             }
 437           }
 438         }
 439         tty->print_raw(st.freeze());
 440       }
 441 #endif // !PRODUCT
 442     }
 443   }
 444 }
 445 
 446 // Deoptimize objects, that is reallocate and relock them, just before they escape through JVMTI.
 447 // The given vframes cover one physical frame.
 448 bool Deoptimization::deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
 449                                                  bool& realloc_failures) {
 450   frame deoptee = chunk->at(0)->fr();
 451   JavaThread* deoptee_thread = chunk->at(0)->thread();
 452   nmethod* nm = deoptee.cb()->as_nmethod_or_null();
 453   RegisterMap map(chunk->at(0)->register_map());
 454   bool deoptimized_objects = false;
 455 
 456   bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
 457 
 458   // Reallocate the non-escaping objects and restore their fields.
 459   if (jvmci_enabled COMPILER2_PRESENT(|| (DoEscapeAnalysis && EliminateAllocations)
 460                                       || EliminateAutoBox || EnableVectorAggressiveReboxing)) {
 461     realloc_failures = rematerialize_objects(thread, Unpack_none, nm, deoptee, map, chunk, deoptimized_objects);
 462   }
 463 
 464   // MonitorInfo structures used in eliminate_locks are not GC safe.
 465   NoSafepointVerifier no_safepoint;
 466 
 467   // Now relock objects if synchronization on them was eliminated.
 468   if (jvmci_enabled COMPILER2_PRESENT(|| ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks))) {
 469     restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
 470   }
 471   return deoptimized_objects;
 472 }
 473 #endif // COMPILER2_OR_JVMCI
 474 
 475 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 476 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
 477   JFR_ONLY(Jfr::check_and_process_sample_request(current);)
 478   // When we get here we are about to unwind the deoptee frame. In order to
 479   // catch not yet safe to use frames, the following stack watermark barrier
 480   // poll will make such frames safe to use.
 481   StackWatermarkSet::before_unwind(current);
 482 
 483   // Note: there is a safepoint safety issue here. No matter whether we enter
 484   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 485   // the vframeArray is created.
 486   //
 487 
 488   // Allocate our special deoptimization ResourceMark
 489   DeoptResourceMark* dmark = new DeoptResourceMark(current);
 490   assert(current->deopt_mark() == nullptr, "Pending deopt!");
 491   current->set_deopt_mark(dmark);
 492 
 493   frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
 494   RegisterMap map(current,
 495                   RegisterMap::UpdateMap::include,
 496                   RegisterMap::ProcessFrames::include,
 497                   RegisterMap::WalkContinuation::skip);
 498   RegisterMap dummy_map(current,
 499                         RegisterMap::UpdateMap::skip,
 500                         RegisterMap::ProcessFrames::include,
 501                         RegisterMap::WalkContinuation::skip);
 502   // Now get the deoptee with a valid map
 503   frame deoptee = stub_frame.sender(&map);
 504   // Set the deoptee nmethod
 505   assert(current->deopt_compiled_method() == nullptr, "Pending deopt!");
 506   nmethod* nm = deoptee.cb()->as_nmethod_or_null();
 507   current->set_deopt_compiled_method(nm);
 508 
 509   if (VerifyStack) {
 510     current->validate_frame_layout();
 511   }
 512 
 513   // Create a growable array of VFrames where each VFrame represents an inlined
 514   // Java frame.  This storage is allocated with the usual system arena.
 515   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 516   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 517   vframe* vf = vframe::new_vframe(&deoptee, &map, current);
 518   while (!vf->is_top()) {
 519     assert(vf->is_compiled_frame(), "Wrong frame type");
 520     chunk->push(compiledVFrame::cast(vf));
 521     vf = vf->sender();
 522   }
 523   assert(vf->is_compiled_frame(), "Wrong frame type");
 524   chunk->push(compiledVFrame::cast(vf));
 525 
 526   bool realloc_failures = false;
 527 
 528 #if COMPILER2_OR_JVMCI
 529   bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
 530 
 531   // Reallocate the non-escaping objects and restore their fields. Then
 532   // relock objects if synchronization on them was eliminated.
 533   if (jvmci_enabled COMPILER2_PRESENT( || (DoEscapeAnalysis && EliminateAllocations)
 534                                        || EliminateAutoBox || EnableVectorAggressiveReboxing )) {
 535     bool unused;
 536     realloc_failures = rematerialize_objects(current, exec_mode, nm, deoptee, map, chunk, unused);
 537   }
 538 #endif // COMPILER2_OR_JVMCI
 539 
 540   // Ensure that no safepoint is taken after pointers have been stored
 541   // in fields of rematerialized objects.  If a safepoint occurs from here on
 542   // out the java state residing in the vframeArray will be missed.
 543   // Locks may be rebaised in a safepoint.
 544   NoSafepointVerifier no_safepoint;
 545 
 546 #if COMPILER2_OR_JVMCI
 547   if ((jvmci_enabled COMPILER2_PRESENT( || ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) ))
 548       && !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
 549     bool unused = false;
 550     restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
 551   }
 552 #endif // COMPILER2_OR_JVMCI
 553 
 554   ScopeDesc* trap_scope = chunk->at(0)->scope();
 555   Handle exceptionObject;
 556   if (trap_scope->rethrow_exception()) {
 557 #ifndef PRODUCT
 558     if (PrintDeoptimizationDetails) {
 559       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());
 560     }
 561 #endif // !PRODUCT
 562 
 563     GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
 564     guarantee(expressions != nullptr && expressions->length() == 1, "should have only exception on stack");
 565     guarantee(exec_mode != Unpack_exception, "rethrow_exception set with Unpack_exception");
 566     ScopeValue* topOfStack = expressions->top();
 567     exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
 568     guarantee(exceptionObject() != nullptr, "exception oop can not be null");
 569   }
 570 
 571   vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
 572 #if COMPILER2_OR_JVMCI
 573   if (realloc_failures) {
 574     // This destroys all ScopedValue bindings.
 575     current->clear_scopedValueBindings();
 576     pop_frames_failed_reallocs(current, array);
 577   }
 578 #endif
 579 
 580   assert(current->vframe_array_head() == nullptr, "Pending deopt!");
 581   current->set_vframe_array_head(array);
 582 
 583   // Now that the vframeArray has been created if we have any deferred local writes
 584   // added by jvmti then we can free up that structure as the data is now in the
 585   // vframeArray
 586 
 587   JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
 588 
 589   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 590   CodeBlob* cb = stub_frame.cb();
 591   // Verify we have the right vframeArray
 592   assert(cb->frame_size() >= 0, "Unexpected frame size");
 593   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 594   assert(unpack_sp == deoptee.unextended_sp(), "must be");
 595 
 596 #ifdef ASSERT
 597   assert(cb->is_deoptimization_stub() ||
 598          cb->is_uncommon_trap_stub() ||
 599          strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
 600          strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
 601          "unexpected code blob: %s", cb->name());
 602 #endif
 603 
 604   // This is a guarantee instead of an assert because if vframe doesn't match
 605   // we will unpack the wrong deoptimized frame and wind up in strange places
 606   // where it will be very difficult to figure out what went wrong. Better
 607   // to die an early death here than some very obscure death later when the
 608   // trail is cold.
 609   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 610 
 611   int number_of_frames = array->frames();
 612 
 613   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 614   // virtual activation, which is the reverse of the elements in the vframes array.
 615   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 616   // +1 because we always have an interpreter return address for the final slot.
 617   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 618   int popframe_extra_args = 0;
 619   // Create an interpreter return address for the stub to use as its return
 620   // address so the skeletal frames are perfectly walkable
 621   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 622 
 623   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 624   // activation be put back on the expression stack of the caller for reexecution
 625   if (JvmtiExport::can_pop_frame() && current->popframe_forcing_deopt_reexecution()) {
 626     popframe_extra_args = in_words(current->popframe_preserved_args_size_in_words());
 627   }
 628 
 629   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 630   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 631   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 632   //
 633   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 634   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 635 
 636   // It's possible that the number of parameters at the call site is
 637   // different than number of arguments in the callee when method
 638   // handles are used.  If the caller is interpreted get the real
 639   // value so that the proper amount of space can be added to it's
 640   // frame.
 641   bool caller_was_method_handle = false;
 642   if (deopt_sender.is_interpreted_frame()) {
 643     methodHandle method(current, deopt_sender.interpreter_frame_method());
 644     Bytecode_invoke cur(method, deopt_sender.interpreter_frame_bci());
 645     if (cur.has_member_arg()) {
 646       // This should cover all real-world cases.  One exception is a pathological chain of
 647       // MH.linkToXXX() linker calls, which only trusted code could do anyway.  To handle that case, we
 648       // would need to get the size from the resolved method entry.  Another exception would
 649       // be an invokedynamic with an adapter that is really a MethodHandle linker.
 650       caller_was_method_handle = true;
 651     }
 652   }
 653 
 654   //
 655   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 656   // frame_sizes/frame_pcs[1] next oldest frame (int)
 657   // frame_sizes/frame_pcs[n] youngest frame (int)
 658   //
 659   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 660   // owns the space for the return address to it's caller).  Confusing ain't it.
 661   //
 662   // The vframe array can address vframes with indices running from
 663   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 664   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 665   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 666   // so things look a little strange in this loop.
 667   //
 668   int callee_parameters = 0;
 669   int callee_locals = 0;
 670   for (int index = 0; index < array->frames(); index++ ) {
 671     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 672     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 673     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 674     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 675                                                                                                     callee_locals,
 676                                                                                                     index == 0,
 677                                                                                                     popframe_extra_args);
 678     // This pc doesn't have to be perfect just good enough to identify the frame
 679     // as interpreted so the skeleton frame will be walkable
 680     // The correct pc will be set when the skeleton frame is completely filled out
 681     // The final pc we store in the loop is wrong and will be overwritten below
 682     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 683 
 684     callee_parameters = array->element(index)->method()->size_of_parameters();
 685     callee_locals = array->element(index)->method()->max_locals();
 686     popframe_extra_args = 0;
 687   }
 688 
 689   // Compute whether the root vframe returns a float or double value.
 690   BasicType return_type;
 691   {
 692     methodHandle method(current, array->element(0)->method());
 693     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 694     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 695   }
 696 
 697   // Compute information for handling adapters and adjusting the frame size of the caller.
 698   int caller_adjustment = 0;
 699 
 700   // Compute the amount the oldest interpreter frame will have to adjust
 701   // its caller's stack by. If the caller is a compiled frame then
 702   // we pretend that the callee has no parameters so that the
 703   // extension counts for the full amount of locals and not just
 704   // locals-parms. This is because without a c2i adapter the parm
 705   // area as created by the compiled frame will not be usable by
 706   // the interpreter. (Depending on the calling convention there
 707   // may not even be enough space).
 708 
 709   // QQQ I'd rather see this pushed down into last_frame_adjust
 710   // and have it take the sender (aka caller).
 711 
 712   if (!deopt_sender.is_interpreted_frame() || caller_was_method_handle) {
 713     caller_adjustment = last_frame_adjust(0, callee_locals);
 714   } else if (callee_locals > callee_parameters) {
 715     // The caller frame may need extending to accommodate
 716     // non-parameter locals of the first unpacked interpreted frame.
 717     // Compute that adjustment.
 718     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 719   }
 720 
 721   // If the sender is deoptimized the we must retrieve the address of the handler
 722   // since the frame will "magically" show the original pc before the deopt
 723   // and we'd undo the deopt.
 724 
 725   frame_pcs[0] = Continuation::is_cont_barrier_frame(deoptee) ? StubRoutines::cont_returnBarrier() : deopt_sender.raw_pc();
 726   if (Continuation::is_continuation_enterSpecial(deopt_sender)) {
 727     ContinuationEntry::from_frame(deopt_sender)->set_argsize(0);
 728   }
 729 
 730   assert(CodeCache::find_blob(frame_pcs[0]) != nullptr, "bad pc");
 731 
 732 #if INCLUDE_JVMCI
 733   if (exceptionObject() != nullptr) {
 734     current->set_exception_oop(exceptionObject());
 735     exec_mode = Unpack_exception;
 736     assert(array->element(0)->rethrow_exception(), "must be");
 737   }
 738 #endif
 739 
 740   if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
 741     assert(current->has_pending_exception(), "should have thrown OOME");
 742     current->set_exception_oop(current->pending_exception());
 743     current->clear_pending_exception();
 744     exec_mode = Unpack_exception;
 745   }
 746 
 747 #if INCLUDE_JVMCI
 748   if (current->frames_to_pop_failed_realloc() > 0) {
 749     current->set_pending_monitorenter(false);
 750   }
 751 #endif
 752 
 753   int caller_actual_parameters = -1; // value not used except for interpreted frames, see below
 754   if (deopt_sender.is_interpreted_frame()) {
 755     caller_actual_parameters = callee_parameters + (caller_was_method_handle ? 1 : 0);
 756   }
 757 
 758   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 759                                       caller_adjustment * BytesPerWord,
 760                                       caller_actual_parameters,
 761                                       number_of_frames,
 762                                       frame_sizes,
 763                                       frame_pcs,
 764                                       return_type,
 765                                       exec_mode);
 766   // On some platforms, we need a way to pass some platform dependent
 767   // information to the unpacking code so the skeletal frames come out
 768   // correct (initial fp value, unextended sp, ...)
 769   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 770 
 771   if (array->frames() > 1) {
 772     if (VerifyStack && TraceDeoptimization) {
 773       tty->print_cr("Deoptimizing method containing inlining");
 774     }
 775   }
 776 
 777   array->set_unroll_block(info);
 778   return info;
 779 }
 780 
 781 // Called to cleanup deoptimization data structures in normal case
 782 // after unpacking to stack and when stack overflow error occurs
 783 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 784                                         vframeArray *array) {
 785 
 786   // Get array if coming from exception
 787   if (array == nullptr) {
 788     array = thread->vframe_array_head();
 789   }
 790   thread->set_vframe_array_head(nullptr);
 791 
 792   // Free the previous UnrollBlock
 793   vframeArray* old_array = thread->vframe_array_last();
 794   thread->set_vframe_array_last(array);
 795 
 796   if (old_array != nullptr) {
 797     UnrollBlock* old_info = old_array->unroll_block();
 798     old_array->set_unroll_block(nullptr);
 799     delete old_info;
 800     delete old_array;
 801   }
 802 
 803   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 804   // inside the vframeArray (StackValueCollections)
 805 
 806   delete thread->deopt_mark();
 807   thread->set_deopt_mark(nullptr);
 808   thread->set_deopt_compiled_method(nullptr);
 809 
 810 
 811   if (JvmtiExport::can_pop_frame()) {
 812     // Regardless of whether we entered this routine with the pending
 813     // popframe condition bit set, we should always clear it now
 814     thread->clear_popframe_condition();
 815   }
 816 
 817   // unpack_frames() is called at the end of the deoptimization handler
 818   // and (in C2) at the end of the uncommon trap handler. Note this fact
 819   // so that an asynchronous stack walker can work again. This counter is
 820   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 821   // the beginning of uncommon_trap().
 822   thread->dec_in_deopt_handler();
 823 }
 824 
 825 // Moved from cpu directories because none of the cpus has callee save values.
 826 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
 827 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
 828 
 829   // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
 830   // the days we had adapter frames. When we deoptimize a situation where a
 831   // compiled caller calls a compiled caller will have registers it expects
 832   // to survive the call to the callee. If we deoptimize the callee the only
 833   // way we can restore these registers is to have the oldest interpreter
 834   // frame that we create restore these values. That is what this routine
 835   // will accomplish.
 836 
 837   // At the moment we have modified c2 to not have any callee save registers
 838   // so this problem does not exist and this routine is just a place holder.
 839 
 840   assert(f->is_interpreted_frame(), "must be interpreted");
 841 }
 842 
 843 #ifndef PRODUCT
 844 #ifdef ASSERT
 845 // Return true if the execution after the provided bytecode continues at the
 846 // next bytecode in the code. This is not the case for gotos, returns, and
 847 // throws.
 848 static bool falls_through(Bytecodes::Code bc) {
 849   switch (bc) {
 850     case Bytecodes::_goto:
 851     case Bytecodes::_goto_w:
 852     case Bytecodes::_athrow:
 853     case Bytecodes::_areturn:
 854     case Bytecodes::_dreturn:
 855     case Bytecodes::_freturn:
 856     case Bytecodes::_ireturn:
 857     case Bytecodes::_lreturn:
 858     case Bytecodes::_jsr:
 859     case Bytecodes::_ret:
 860     case Bytecodes::_return:
 861     case Bytecodes::_lookupswitch:
 862     case Bytecodes::_tableswitch:
 863       return false;
 864     default:
 865       return true;
 866   }
 867 }
 868 #endif
 869 #endif
 870 
 871 // Return BasicType of value being returned
 872 JRT_LEAF_PROF_NO_THREAD(BasicType, Deoptimization, unpack_frames, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 873   assert(thread == JavaThread::current(), "pre-condition");
 874 
 875   // We are already active in the special DeoptResourceMark any ResourceObj's we
 876   // allocate will be freed at the end of the routine.
 877 
 878   // JRT_LEAF methods don't normally allocate handles and there is a
 879   // NoHandleMark to enforce that. It is actually safe to use Handles
 880   // in a JRT_LEAF method, and sometimes desirable, but to do so we
 881   // must use ResetNoHandleMark to bypass the NoHandleMark, and
 882   // then use a HandleMark to ensure any Handles we do create are
 883   // cleaned up in this scope.
 884   ResetNoHandleMark rnhm;
 885   HandleMark hm(thread);
 886 
 887   frame stub_frame = thread->last_frame();
 888 
 889   Continuation::notify_deopt(thread, stub_frame.sp());
 890 
 891   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 892   // must point to the vframeArray for the unpack frame.
 893   vframeArray* array = thread->vframe_array_head();
 894   UnrollBlock* info = array->unroll_block();
 895 
 896   // We set the last_Java frame. But the stack isn't really parsable here. So we
 897   // clear it to make sure JFR understands not to try and walk stacks from events
 898   // in here.
 899   intptr_t* sp = thread->frame_anchor()->last_Java_sp();
 900   thread->frame_anchor()->set_last_Java_sp(nullptr);
 901 
 902   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 903   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 904 
 905   thread->frame_anchor()->set_last_Java_sp(sp);
 906 
 907   BasicType bt = info->return_type();
 908 
 909   // If we have an exception pending, claim that the return type is an oop
 910   // so the deopt_blob does not overwrite the exception_oop.
 911 
 912   if (exec_mode == Unpack_exception)
 913     bt = T_OBJECT;
 914 
 915   // Cleanup thread deopt data
 916   cleanup_deopt_info(thread, array);
 917 
 918 #ifndef PRODUCT
 919   if (VerifyStack) {
 920     ResourceMark res_mark;
 921     // Clear pending exception to not break verification code (restored afterwards)
 922     PreserveExceptionMark pm(thread);
 923 
 924     thread->validate_frame_layout();
 925 
 926     // Verify that the just-unpacked frames match the interpreter's
 927     // notions of expression stack and locals
 928     vframeArray* cur_array = thread->vframe_array_last();
 929     RegisterMap rm(thread,
 930                    RegisterMap::UpdateMap::skip,
 931                    RegisterMap::ProcessFrames::include,
 932                    RegisterMap::WalkContinuation::skip);
 933     rm.set_include_argument_oops(false);
 934     int callee_size_of_parameters = 0;
 935     for (int frame_idx = 0; frame_idx < cur_array->frames(); frame_idx++) {
 936       bool is_top_frame = (frame_idx == 0);
 937       vframeArrayElement* el = cur_array->element(frame_idx);
 938       frame* iframe = el->iframe();
 939       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 940       methodHandle mh(thread, iframe->interpreter_frame_method());
 941       bool reexecute = el->should_reexecute();
 942 
 943       int cur_invoke_parameter_size = 0;
 944       int top_frame_expression_stack_adjustment = 0;
 945       int max_bci = mh->code_size();
 946       BytecodeStream str(mh, iframe->interpreter_frame_bci());
 947       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 948       Bytecodes::Code cur_code = str.next();
 949 
 950       if (!reexecute && !Bytecodes::is_invoke(cur_code)) {
 951         // We can only compute OopMaps for the before state, so we need to roll forward
 952         // to the next bytecode.
 953         assert(is_top_frame, "must be");
 954         assert(falls_through(cur_code), "must be");
 955         assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
 956         assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 957 
 958         // Need to subtract off the size of the result type of
 959         // the bytecode because this is not described in the
 960         // debug info but returned to the interpreter in the TOS
 961         // caching register
 962         BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 963         if (bytecode_result_type != T_ILLEGAL) {
 964           top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 965         }
 966         assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
 967 
 968         cur_code = str.next();
 969         // Reflect the fact that we have rolled forward and now need
 970         // top_frame_expression_stack_adjustment
 971         reexecute = true;
 972       }
 973 
 974       assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
 975       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 976 
 977       // Get the oop map for this bci
 978       InterpreterOopMap mask;
 979       OopMapCache::compute_one_oop_map(mh, str.bci(), &mask);
 980       // Check to see if we can grab the number of outgoing arguments
 981       // at an uncommon trap for an invoke (where the compiler
 982       // generates debug info before the invoke has executed)
 983       if (Bytecodes::is_invoke(cur_code)) {
 984         Bytecode_invoke invoke(mh, str.bci());
 985         cur_invoke_parameter_size = invoke.size_of_parameters();
 986         if (!is_top_frame && invoke.has_member_arg()) {
 987           callee_size_of_parameters++;
 988         }
 989       }
 990 
 991       // Verify stack depth and oops in frame
 992       auto match = [&]() {
 993         int iframe_expr_ssize = iframe->interpreter_frame_expression_stack_size();
 994 #if INCLUDE_JVMCI
 995         if (is_top_frame && el->rethrow_exception()) {
 996           return iframe_expr_ssize == 1;
 997         }
 998 #endif
 999         // This should only be needed for C1
1000         if (is_top_frame && exec_mode == Unpack_exception && iframe_expr_ssize == 0) {
1001           return true;
1002         }
1003         if (reexecute) {
1004           int expr_ssize_before = iframe_expr_ssize + top_frame_expression_stack_adjustment;
1005           int oopmap_expr_invoke_ssize = mask.expression_stack_size() + cur_invoke_parameter_size;
1006           return expr_ssize_before == oopmap_expr_invoke_ssize;
1007         } else {
1008           int oopmap_expr_callee_ssize = mask.expression_stack_size() + callee_size_of_parameters;
1009           return iframe_expr_ssize == oopmap_expr_callee_ssize;
1010         }
1011       };
1012       if (!match()) {
1013         // Print out some information that will help us debug the problem
1014         tty->print_cr("Wrong number of expression stack elements during deoptimization");
1015         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", frame_idx, cur_array->frames() - 1);
1016         tty->print_cr("  Current code %s", Bytecodes::name(cur_code));
1017         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
1018                       iframe->interpreter_frame_expression_stack_size());
1019         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
1020         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
1021         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
1022         tty->print_cr("  exec_mode = %d", exec_mode);
1023         tty->print_cr("  original should_reexecute = %s", el->should_reexecute() ? "true" : "false");
1024         tty->print_cr("  reexecute = %s%s", reexecute ? "true" : "false",
1025                       (reexecute != el->should_reexecute()) ? " (changed)" : "");
1026 #if INCLUDE_JVMCI
1027         tty->print_cr("  rethrow_exception = %s", el->rethrow_exception() ? "true" : "false");
1028 #endif
1029         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
1030         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
1031         tty->print_cr("  Interpreted frames:");
1032         for (int k = 0; k < cur_array->frames(); k++) {
1033           vframeArrayElement* el = cur_array->element(k);
1034           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
1035         }
1036         cur_array->print_on_2(tty);
1037         guarantee(false, "wrong number of expression stack elements during deopt");
1038       }
1039       VerifyOopClosure verify;
1040       iframe->oops_interpreted_do(&verify, &rm, false);
1041       callee_size_of_parameters = mh->size_of_parameters();
1042     }
1043   }
1044 #endif // !PRODUCT
1045 
1046   return bt;
1047 JRT_END
1048 
1049 class DeoptimizeMarkedHandshakeClosure : public HandshakeClosure {
1050  public:
1051   DeoptimizeMarkedHandshakeClosure() : HandshakeClosure("Deoptimize") {}
1052   void do_thread(Thread* thread) {
1053     JavaThread* jt = JavaThread::cast(thread);
1054     jt->deoptimize_marked_methods();
1055   }
1056 };
1057 
1058 void Deoptimization::deoptimize_all_marked() {
1059   ResourceMark rm;
1060 
1061   // Make the dependent methods not entrant
1062   CodeCache::make_marked_nmethods_deoptimized();
1063 
1064   DeoptimizeMarkedHandshakeClosure deopt;
1065   if (SafepointSynchronize::is_at_safepoint()) {
1066     Threads::java_threads_do(&deopt);
1067   } else {
1068     Handshake::execute(&deopt);
1069   }
1070 }
1071 
1072 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1073   = Deoptimization::Action_reinterpret;
1074 
1075 #if INCLUDE_JVMCI
1076 template<typename CacheType>
1077 class BoxCacheBase : public CHeapObj<mtCompiler> {
1078 protected:
1079   static InstanceKlass* find_cache_klass(Thread* thread, Symbol* klass_name) {
1080     ResourceMark rm(thread);
1081     char* klass_name_str = klass_name->as_C_string();
1082     InstanceKlass* ik = SystemDictionary::find_instance_klass(thread, klass_name, Handle());
1083     guarantee(ik != nullptr, "%s must be loaded", klass_name_str);
1084     if (!ik->is_in_error_state()) {
1085       guarantee(ik->is_initialized(), "%s must be initialized", klass_name_str);
1086       CacheType::compute_offsets(ik);
1087     }
1088     return ik;
1089   }
1090 };
1091 
1092 template<typename PrimitiveType, typename CacheType, typename BoxType> class BoxCache  : public BoxCacheBase<CacheType> {
1093   PrimitiveType _low;
1094   PrimitiveType _high;
1095   jobject _cache;
1096 protected:
1097   static BoxCache<PrimitiveType, CacheType, BoxType> *_singleton;
1098   BoxCache(Thread* thread) {
1099     InstanceKlass* ik = BoxCacheBase<CacheType>::find_cache_klass(thread, CacheType::symbol());
1100     if (ik->is_in_error_state()) {
1101       _low = 1;
1102       _high = 0;
1103       _cache = nullptr;
1104     } else {
1105       objArrayOop cache = CacheType::cache(ik);
1106       assert(cache->length() > 0, "Empty cache");
1107       _low = BoxType::value(cache->obj_at(0));
1108       _high = checked_cast<PrimitiveType>(_low + cache->length() - 1);
1109       _cache = JNIHandles::make_global(Handle(thread, cache));
1110     }
1111   }
1112   ~BoxCache() {
1113     JNIHandles::destroy_global(_cache);
1114   }
1115 public:
1116   static BoxCache<PrimitiveType, CacheType, BoxType>* singleton(Thread* thread) {
1117     if (_singleton == nullptr) {
1118       BoxCache<PrimitiveType, CacheType, BoxType>* s = new BoxCache<PrimitiveType, CacheType, BoxType>(thread);
1119       if (!AtomicAccess::replace_if_null(&_singleton, s)) {
1120         delete s;
1121       }
1122     }
1123     return _singleton;
1124   }
1125   oop lookup(PrimitiveType value) {
1126     if (_low <= value && value <= _high) {
1127       int offset = checked_cast<int>(value - _low);
1128       return objArrayOop(JNIHandles::resolve_non_null(_cache))->obj_at(offset);
1129     }
1130     return nullptr;
1131   }
1132   oop lookup_raw(intptr_t raw_value, bool& cache_init_error) {
1133     if (_cache == nullptr) {
1134       cache_init_error = true;
1135       return nullptr;
1136     }
1137     // Have to cast to avoid little/big-endian problems.
1138     if (sizeof(PrimitiveType) > sizeof(jint)) {
1139       jlong value = (jlong)raw_value;
1140       return lookup(value);
1141     }
1142     PrimitiveType value = (PrimitiveType)*((jint*)&raw_value);
1143     return lookup(value);
1144   }
1145 };
1146 
1147 typedef BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer> IntegerBoxCache;
1148 typedef BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long> LongBoxCache;
1149 typedef BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character> CharacterBoxCache;
1150 typedef BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short> ShortBoxCache;
1151 typedef BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte> ByteBoxCache;
1152 
1153 template<> BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>* BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>::_singleton = nullptr;
1154 template<> BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>* BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>::_singleton = nullptr;
1155 template<> BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>* BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>::_singleton = nullptr;
1156 template<> BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>* BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>::_singleton = nullptr;
1157 template<> BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>* BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>::_singleton = nullptr;
1158 
1159 class BooleanBoxCache : public BoxCacheBase<java_lang_Boolean> {
1160   jobject _true_cache;
1161   jobject _false_cache;
1162 protected:
1163   static BooleanBoxCache *_singleton;
1164   BooleanBoxCache(Thread *thread) {
1165     InstanceKlass* ik = find_cache_klass(thread, java_lang_Boolean::symbol());
1166     if (ik->is_in_error_state()) {
1167       _true_cache = nullptr;
1168       _false_cache = nullptr;
1169     } else {
1170       _true_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_TRUE(ik)));
1171       _false_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_FALSE(ik)));
1172     }
1173   }
1174   ~BooleanBoxCache() {
1175     JNIHandles::destroy_global(_true_cache);
1176     JNIHandles::destroy_global(_false_cache);
1177   }
1178 public:
1179   static BooleanBoxCache* singleton(Thread* thread) {
1180     if (_singleton == nullptr) {
1181       BooleanBoxCache* s = new BooleanBoxCache(thread);
1182       if (!AtomicAccess::replace_if_null(&_singleton, s)) {
1183         delete s;
1184       }
1185     }
1186     return _singleton;
1187   }
1188   oop lookup_raw(intptr_t raw_value, bool& cache_in_error) {
1189     if (_true_cache == nullptr) {
1190       cache_in_error = true;
1191       return nullptr;
1192     }
1193     // Have to cast to avoid little/big-endian problems.
1194     jboolean value = (jboolean)*((jint*)&raw_value);
1195     return lookup(value);
1196   }
1197   oop lookup(jboolean value) {
1198     if (value != 0) {
1199       return JNIHandles::resolve_non_null(_true_cache);
1200     }
1201     return JNIHandles::resolve_non_null(_false_cache);
1202   }
1203 };
1204 
1205 BooleanBoxCache* BooleanBoxCache::_singleton = nullptr;
1206 
1207 oop Deoptimization::get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, bool& cache_init_error, TRAPS) {
1208    Klass* k = java_lang_Class::as_Klass(bv->klass()->as_ConstantOopReadValue()->value()());
1209    BasicType box_type = vmClasses::box_klass_type(k);
1210    if (box_type != T_OBJECT) {
1211      StackValue* value = StackValue::create_stack_value(fr, reg_map, bv->field_at(box_type == T_LONG ? 1 : 0));
1212      switch(box_type) {
1213        case T_INT:     return IntegerBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1214        case T_CHAR:    return CharacterBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1215        case T_SHORT:   return ShortBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1216        case T_BYTE:    return ByteBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1217        case T_BOOLEAN: return BooleanBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1218        case T_LONG:    return LongBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1219        default:;
1220      }
1221    }
1222    return nullptr;
1223 }
1224 #endif // INCLUDE_JVMCI
1225 
1226 #if COMPILER2_OR_JVMCI
1227 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1228   Handle pending_exception(THREAD, thread->pending_exception());
1229   const char* exception_file = thread->exception_file();
1230   int exception_line = thread->exception_line();
1231   thread->clear_pending_exception();
1232 
1233   bool failures = false;
1234 
1235   for (int i = 0; i < objects->length(); i++) {
1236     assert(objects->at(i)->is_object(), "invalid debug information");
1237     ObjectValue* sv = (ObjectValue*) objects->at(i);
1238 
1239     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1240     oop obj = nullptr;
1241 
1242     bool cache_init_error = false;
1243     if (k->is_instance_klass()) {
1244 #if INCLUDE_JVMCI
1245       nmethod* nm = fr->cb()->as_nmethod_or_null();
1246       if (nm->is_compiled_by_jvmci() && sv->is_auto_box()) {
1247         AutoBoxObjectValue* abv = (AutoBoxObjectValue*) sv;
1248         obj = get_cached_box(abv, fr, reg_map, cache_init_error, THREAD);
1249         if (obj != nullptr) {
1250           // Set the flag to indicate the box came from a cache, so that we can skip the field reassignment for it.
1251           abv->set_cached(true);
1252         } else if (cache_init_error) {
1253           // Results in an OOME which is valid (as opposed to a class initialization error)
1254           // and is fine for the rare case a cache initialization failing.
1255           failures = true;
1256         }
1257       }
1258 #endif // INCLUDE_JVMCI
1259 
1260       InstanceKlass* ik = InstanceKlass::cast(k);
1261       if (obj == nullptr && !cache_init_error) {
1262         InternalOOMEMark iom(THREAD);
1263         if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1264           obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1265         } else {
1266           obj = ik->allocate_instance(THREAD);
1267         }
1268       }
1269     } else if (k->is_typeArray_klass()) {
1270       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1271       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1272       int len = sv->field_size() / type2size[ak->element_type()];
1273       InternalOOMEMark iom(THREAD);
1274       obj = ak->allocate_instance(len, THREAD);
1275     } else if (k->is_objArray_klass()) {
1276       ObjArrayKlass* ak = ObjArrayKlass::cast(k);
1277       InternalOOMEMark iom(THREAD);
1278       obj = ak->allocate_instance(sv->field_size(), THREAD);
1279     }
1280 
1281     if (obj == nullptr) {
1282       failures = true;
1283     }
1284 
1285     assert(sv->value().is_null(), "redundant reallocation");
1286     assert(obj != nullptr || HAS_PENDING_EXCEPTION || cache_init_error, "allocation should succeed or we should get an exception");
1287     CLEAR_PENDING_EXCEPTION;
1288     sv->set_value(obj);
1289   }
1290 
1291   if (failures) {
1292     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1293   } else if (pending_exception.not_null()) {
1294     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1295   }
1296 
1297   return failures;
1298 }
1299 
1300 #if INCLUDE_JVMCI
1301 /**
1302  * For primitive types whose kind gets "erased" at runtime (shorts become stack ints),
1303  * we need to somehow be able to recover the actual kind to be able to write the correct
1304  * amount of bytes.
1305  * For that purpose, this method assumes that, for an entry spanning n bytes at index i,
1306  * the entries at index n + 1 to n + i are 'markers'.
1307  * For example, if we were writing a short at index 4 of a byte array of size 8, the
1308  * expected form of the array would be:
1309  *
1310  * {b0, b1, b2, b3, INT, marker, b6, b7}
1311  *
1312  * Thus, in order to get back the size of the entry, we simply need to count the number
1313  * of marked entries
1314  *
1315  * @param virtualArray the virtualized byte array
1316  * @param i index of the virtual entry we are recovering
1317  * @return The number of bytes the entry spans
1318  */
1319 static int count_number_of_bytes_for_entry(ObjectValue *virtualArray, int i) {
1320   int index = i;
1321   while (++index < virtualArray->field_size() &&
1322            virtualArray->field_at(index)->is_marker()) {}
1323   return index - i;
1324 }
1325 
1326 /**
1327  * If there was a guarantee for byte array to always start aligned to a long, we could
1328  * do a simple check on the parity of the index. Unfortunately, that is not always the
1329  * case. Thus, we check alignment of the actual address we are writing to.
1330  * In the unlikely case index 0 is 5-aligned for example, it would then be possible to
1331  * write a long to index 3.
1332  */
1333 static jbyte* check_alignment_get_addr(typeArrayOop obj, int index, int expected_alignment) {
1334     jbyte* res = obj->byte_at_addr(index);
1335     assert((((intptr_t) res) % expected_alignment) == 0, "Non-aligned write");
1336     return res;
1337 }
1338 
1339 static void byte_array_put(typeArrayOop obj, StackValue* value, int index, int byte_count) {
1340   switch (byte_count) {
1341     case 1:
1342       obj->byte_at_put(index, (jbyte) value->get_jint());
1343       break;
1344     case 2:
1345       *((jshort *) check_alignment_get_addr(obj, index, 2)) = (jshort) value->get_jint();
1346       break;
1347     case 4:
1348       *((jint *) check_alignment_get_addr(obj, index, 4)) = value->get_jint();
1349       break;
1350     case 8:
1351       *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) value->get_intptr();
1352       break;
1353     default:
1354       ShouldNotReachHere();
1355   }
1356 }
1357 #endif // INCLUDE_JVMCI
1358 
1359 
1360 // restore elements of an eliminated type array
1361 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1362   int index = 0;
1363 
1364   for (int i = 0; i < sv->field_size(); i++) {
1365     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1366     switch(type) {
1367     case T_LONG: case T_DOUBLE: {
1368       assert(value->type() == T_INT, "Agreement.");
1369       StackValue* low =
1370         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1371 #ifdef _LP64
1372       jlong res = (jlong)low->get_intptr();
1373 #else
1374       jlong res = jlong_from(value->get_jint(), low->get_jint());
1375 #endif
1376       obj->long_at_put(index, res);
1377       break;
1378     }
1379 
1380     case T_INT: case T_FLOAT: { // 4 bytes.
1381       assert(value->type() == T_INT, "Agreement.");
1382       bool big_value = false;
1383       if (i + 1 < sv->field_size() && type == T_INT) {
1384         if (sv->field_at(i)->is_location()) {
1385           Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
1386           if (type == Location::dbl || type == Location::lng) {
1387             big_value = true;
1388           }
1389         } else if (sv->field_at(i)->is_constant_int()) {
1390           ScopeValue* next_scope_field = sv->field_at(i + 1);
1391           if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1392             big_value = true;
1393           }
1394         }
1395       }
1396 
1397       if (big_value) {
1398         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1399   #ifdef _LP64
1400         jlong res = (jlong)low->get_intptr();
1401   #else
1402         jlong res = jlong_from(value->get_jint(), low->get_jint());
1403   #endif
1404         obj->int_at_put(index, *(jint*)&res);
1405         obj->int_at_put(++index, *((jint*)&res + 1));
1406       } else {
1407         obj->int_at_put(index, value->get_jint());
1408       }
1409       break;
1410     }
1411 
1412     case T_SHORT:
1413       assert(value->type() == T_INT, "Agreement.");
1414       obj->short_at_put(index, (jshort)value->get_jint());
1415       break;
1416 
1417     case T_CHAR:
1418       assert(value->type() == T_INT, "Agreement.");
1419       obj->char_at_put(index, (jchar)value->get_jint());
1420       break;
1421 
1422     case T_BYTE: {
1423       assert(value->type() == T_INT, "Agreement.");
1424 #if INCLUDE_JVMCI
1425       // The value we get is erased as a regular int. We will need to find its actual byte count 'by hand'.
1426       int byte_count = count_number_of_bytes_for_entry(sv, i);
1427       byte_array_put(obj, value, index, byte_count);
1428       // According to byte_count contract, the values from i + 1 to i + byte_count are illegal values. Skip.
1429       i += byte_count - 1; // Balance the loop counter.
1430       index += byte_count;
1431       // index has been updated so continue at top of loop
1432       continue;
1433 #else
1434       obj->byte_at_put(index, (jbyte)value->get_jint());
1435       break;
1436 #endif // INCLUDE_JVMCI
1437     }
1438 
1439     case T_BOOLEAN: {
1440       assert(value->type() == T_INT, "Agreement.");
1441       obj->bool_at_put(index, (jboolean)value->get_jint());
1442       break;
1443     }
1444 
1445       default:
1446         ShouldNotReachHere();
1447     }
1448     index++;
1449   }
1450 }
1451 
1452 // restore fields of an eliminated object array
1453 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1454   for (int i = 0; i < sv->field_size(); i++) {
1455     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1456     assert(value->type() == T_OBJECT, "object element expected");
1457     obj->obj_at_put(i, value->get_obj()());
1458   }
1459 }
1460 
1461 class ReassignedField {
1462 public:
1463   int _offset;
1464   BasicType _type;
1465 public:
1466   ReassignedField() {
1467     _offset = 0;
1468     _type = T_ILLEGAL;
1469   }
1470 };
1471 
1472 // Gets the fields of `klass` that are eliminated by escape analysis and need to be reassigned
1473 static GrowableArray<ReassignedField>* get_reassigned_fields(InstanceKlass* klass, GrowableArray<ReassignedField>* fields, bool is_jvmci) {
1474   InstanceKlass* super = klass->super();
1475   if (super != nullptr) {
1476     get_reassigned_fields(super, fields, is_jvmci);
1477   }
1478   for (AllFieldStream fs(klass); !fs.done(); fs.next()) {
1479     if (!fs.access_flags().is_static() && (is_jvmci || !fs.field_flags().is_injected())) {
1480       ReassignedField field;
1481       field._offset = fs.offset();
1482       field._type = Signature::basic_type(fs.signature());
1483       fields->append(field);
1484     }
1485   }
1486   return fields;
1487 }
1488 
1489 // Restore fields of an eliminated instance object employing the same field order used by the compiler.
1490 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool is_jvmci) {
1491   GrowableArray<ReassignedField>* fields = get_reassigned_fields(klass, new GrowableArray<ReassignedField>(), is_jvmci);
1492   for (int i = 0; i < fields->length(); i++) {
1493     ScopeValue* scope_field = sv->field_at(svIndex);
1494     StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1495     int offset = fields->at(i)._offset;
1496     BasicType type = fields->at(i)._type;
1497     switch (type) {
1498       case T_OBJECT: case T_ARRAY:
1499         assert(value->type() == T_OBJECT, "Agreement.");
1500         obj->obj_field_put(offset, value->get_obj()());
1501         break;
1502 
1503       case T_INT: case T_FLOAT: { // 4 bytes.
1504         assert(value->type() == T_INT, "Agreement.");
1505         bool big_value = false;
1506         if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1507           if (scope_field->is_location()) {
1508             Location::Type type = ((LocationValue*) scope_field)->location().type();
1509             if (type == Location::dbl || type == Location::lng) {
1510               big_value = true;
1511             }
1512           }
1513           if (scope_field->is_constant_int()) {
1514             ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1515             if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1516               big_value = true;
1517             }
1518           }
1519         }
1520 
1521         if (big_value) {
1522           i++;
1523           assert(i < fields->length(), "second T_INT field needed");
1524           assert(fields->at(i)._type == T_INT, "T_INT field needed");
1525         } else {
1526           obj->int_field_put(offset, value->get_jint());
1527           break;
1528         }
1529       }
1530         /* no break */
1531 
1532       case T_LONG: case T_DOUBLE: {
1533         assert(value->type() == T_INT, "Agreement.");
1534         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1535 #ifdef _LP64
1536         jlong res = (jlong)low->get_intptr();
1537 #else
1538         jlong res = jlong_from(value->get_jint(), low->get_jint());
1539 #endif
1540         obj->long_field_put(offset, res);
1541         break;
1542       }
1543 
1544       case T_SHORT:
1545         assert(value->type() == T_INT, "Agreement.");
1546         obj->short_field_put(offset, (jshort)value->get_jint());
1547         break;
1548 
1549       case T_CHAR:
1550         assert(value->type() == T_INT, "Agreement.");
1551         obj->char_field_put(offset, (jchar)value->get_jint());
1552         break;
1553 
1554       case T_BYTE:
1555         assert(value->type() == T_INT, "Agreement.");
1556         obj->byte_field_put(offset, (jbyte)value->get_jint());
1557         break;
1558 
1559       case T_BOOLEAN:
1560         assert(value->type() == T_INT, "Agreement.");
1561         obj->bool_field_put(offset, (jboolean)value->get_jint());
1562         break;
1563 
1564       default:
1565         ShouldNotReachHere();
1566     }
1567     svIndex++;
1568   }
1569   return svIndex;
1570 }
1571 
1572 // restore fields of all eliminated objects and arrays
1573 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool is_jvmci) {
1574   for (int i = 0; i < objects->length(); i++) {
1575     assert(objects->at(i)->is_object(), "invalid debug information");
1576     ObjectValue* sv = (ObjectValue*) objects->at(i);
1577     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1578     Handle obj = sv->value();
1579     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1580 #ifndef PRODUCT
1581     if (PrintDeoptimizationDetails) {
1582       tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1583     }
1584 #endif // !PRODUCT
1585 
1586     if (obj.is_null()) {
1587       continue;
1588     }
1589 
1590 #if INCLUDE_JVMCI
1591     // Don't reassign fields of boxes that came from a cache. Caches may be in CDS.
1592     if (sv->is_auto_box() && ((AutoBoxObjectValue*) sv)->is_cached()) {
1593       continue;
1594     }
1595 #endif // INCLUDE_JVMCI
1596     if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1597       assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1598       ScopeValue* payload = sv->field_at(0);
1599       if (payload->is_location() &&
1600           payload->as_LocationValue()->location().type() == Location::vector) {
1601 #ifndef PRODUCT
1602         if (PrintDeoptimizationDetails) {
1603           tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1604           if (Verbose) {
1605             Handle obj = sv->value();
1606             k->oop_print_on(obj(), tty);
1607           }
1608         }
1609 #endif // !PRODUCT
1610         continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1611       }
1612       // Else fall-through to do assignment for scalar-replaced boxed vector representation
1613       // which could be restored after vector object allocation.
1614     }
1615     if (k->is_instance_klass()) {
1616       InstanceKlass* ik = InstanceKlass::cast(k);
1617       reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), is_jvmci);
1618     } else if (k->is_typeArray_klass()) {
1619       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1620       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1621     } else if (k->is_objArray_klass()) {
1622       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1623     }
1624   }
1625   // These objects may escape when we return to Interpreter after deoptimization.
1626   // We need barrier so that stores that initialize these objects can't be reordered
1627   // with subsequent stores that make these objects accessible by other threads.
1628   OrderAccess::storestore();
1629 }
1630 
1631 
1632 // relock objects for which synchronization was eliminated
1633 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1634                                     JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1635   bool relocked_objects = false;
1636   for (int i = 0; i < monitors->length(); i++) {
1637     MonitorInfo* mon_info = monitors->at(i);
1638     if (mon_info->eliminated()) {
1639       assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1640       relocked_objects = true;
1641       if (!mon_info->owner_is_scalar_replaced()) {
1642         Handle obj(thread, mon_info->owner());
1643         markWord mark = obj->mark();
1644         if (exec_mode == Unpack_none) {
1645           if (mark.has_monitor()) {
1646             // defer relocking if the deoptee thread is currently waiting for obj
1647             ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1648             if (waiting_monitor != nullptr && waiting_monitor->object() == obj()) {
1649               assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1650               if (UseObjectMonitorTable) {
1651                 mon_info->lock()->clear_object_monitor_cache();
1652               }
1653 #ifdef ASSERT
1654               else {
1655                 assert(!UseObjectMonitorTable, "must be");
1656                 mon_info->lock()->set_bad_monitor_deopt();
1657               }
1658 #endif
1659               JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1660               continue;
1661             }
1662           }
1663         }
1664         BasicLock* lock = mon_info->lock();
1665         // We have lost information about the correct state of the lock stack.
1666         // Entering may create an invalid lock stack. Inflate the lock if it
1667         // was fast_locked to restore the valid lock stack.
1668         if (UseObjectMonitorTable) {
1669           // UseObjectMonitorTable expects the BasicLock cache to be either a
1670           // valid ObjectMonitor* or nullptr. Right now it is garbage, set it
1671           // to nullptr.
1672           lock->clear_object_monitor_cache();
1673         }
1674         ObjectSynchronizer::enter_for(obj, lock, deoptee_thread);
1675         if (deoptee_thread->lock_stack().contains(obj())) {
1676             LightweightSynchronizer::inflate_fast_locked_object(obj(), ObjectSynchronizer::InflateCause::inflate_cause_vm_internal,
1677                                                               deoptee_thread, thread);
1678         }
1679         assert(mon_info->owner()->is_locked(), "object must be locked now");
1680         assert(obj->mark().has_monitor(), "must be");
1681         assert(!deoptee_thread->lock_stack().contains(obj()), "must be");
1682         assert(ObjectSynchronizer::read_monitor(thread, obj(), obj->mark())->has_owner(deoptee_thread), "must be");
1683       }
1684     }
1685   }
1686   return relocked_objects;
1687 }
1688 #endif // COMPILER2_OR_JVMCI
1689 
1690 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1691   Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1692 
1693   // Register map for next frame (used for stack crawl).  We capture
1694   // the state of the deopt'ing frame's caller.  Thus if we need to
1695   // stuff a C2I adapter we can properly fill in the callee-save
1696   // register locations.
1697   frame caller = fr.sender(reg_map);
1698   int frame_size = pointer_delta_as_int(caller.sp(), fr.sp());
1699 
1700   frame sender = caller;
1701 
1702   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1703   // the vframeArray containing the unpacking information is allocated in the C heap.
1704   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1705   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1706 
1707   // Compare the vframeArray to the collected vframes
1708   assert(array->structural_compare(thread, chunk), "just checking");
1709 
1710   if (TraceDeoptimization) {
1711     ResourceMark rm;
1712     stringStream st;
1713     st.print_cr("DEOPT PACKING thread=" INTPTR_FORMAT " vframeArray=" INTPTR_FORMAT, p2i(thread), p2i(array));
1714     st.print("   ");
1715     fr.print_on(&st);
1716     st.print_cr("   Virtual frames (innermost/newest first):");
1717     for (int index = 0; index < chunk->length(); index++) {
1718       compiledVFrame* vf = chunk->at(index);
1719       int bci = vf->raw_bci();
1720       const char* code_name;
1721       if (bci == SynchronizationEntryBCI) {
1722         code_name = "sync entry";
1723       } else {
1724         Bytecodes::Code code = vf->method()->code_at(bci);
1725         code_name = Bytecodes::name(code);
1726       }
1727 
1728       st.print("      VFrame %d (" INTPTR_FORMAT ")", index, p2i(vf));
1729       st.print(" - %s", vf->method()->name_and_sig_as_C_string());
1730       st.print(" - %s", code_name);
1731       st.print_cr(" @ bci=%d ", bci);
1732     }
1733     tty->print_raw(st.freeze());
1734     tty->cr();
1735   }
1736 
1737   return array;
1738 }
1739 
1740 #if COMPILER2_OR_JVMCI
1741 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1742   // Reallocation of some scalar replaced objects failed. Record
1743   // that we need to pop all the interpreter frames for the
1744   // deoptimized compiled frame.
1745   assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1746   thread->set_frames_to_pop_failed_realloc(array->frames());
1747   // Unlock all monitors here otherwise the interpreter will see a
1748   // mix of locked and unlocked monitors (because of failed
1749   // reallocations of synchronized objects) and be confused.
1750   for (int i = 0; i < array->frames(); i++) {
1751     MonitorChunk* monitors = array->element(i)->monitors();
1752     if (monitors != nullptr) {
1753       // Unlock in reverse order starting from most nested monitor.
1754       for (int j = (monitors->number_of_monitors() - 1); j >= 0; j--) {
1755         BasicObjectLock* src = monitors->at(j);
1756         if (src->obj() != nullptr) {
1757           ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1758         }
1759       }
1760       array->element(i)->free_monitors();
1761 #ifdef ASSERT
1762       array->element(i)->set_removed_monitors();
1763 #endif
1764     }
1765   }
1766 }
1767 #endif
1768 
1769 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1770   assert(fr.can_be_deoptimized(), "checking frame type");
1771 
1772   nmethod* nm = fr.cb()->as_nmethod_or_null();
1773   assert(nm != nullptr, "only compiled methods can deopt");
1774   DeoptAction action = (nm->is_not_entrant() ? Action_make_not_entrant : Action_none);
1775   ScopeDesc* cur_sd = nm->scope_desc_at(fr.pc());
1776   Bytecodes::Code bc = (cur_sd->bci() == -1 ? Bytecodes::_nop // deopt on method entry
1777                                             : cur_sd->method()->java_code_at(cur_sd->bci()));
1778   gather_statistics(nm, reason, action, bc);
1779 
1780   if (LogCompilation && xtty != nullptr) {
1781     ttyLocker ttyl;
1782     xtty->begin_head("deoptimized thread='%zu' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1783     nm->log_identity(xtty);
1784     xtty->end_head();
1785     for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1786       xtty->begin_elem("jvms bci='%d'", sd->bci());
1787       xtty->method(sd->method());
1788       xtty->end_elem();
1789       if (sd->is_top())  break;
1790     }
1791     xtty->tail("deoptimized");
1792   }
1793 
1794   Continuation::notify_deopt(thread, fr.sp());
1795 
1796   // Patch the compiled method so that when execution returns to it we will
1797   // deopt the execution state and return to the interpreter.
1798   fr.deoptimize(thread);
1799 }
1800 
1801 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1802   // Deoptimize only if the frame comes from compile code.
1803   // Do not deoptimize the frame which is already patched
1804   // during the execution of the loops below.
1805   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1806     return;
1807   }
1808   ResourceMark rm;
1809   deoptimize_single_frame(thread, fr, reason);
1810 }
1811 
1812 #if INCLUDE_JVMCI
1813 address Deoptimization::deoptimize_for_missing_exception_handler(nmethod* nm) {
1814   // there is no exception handler for this pc => deoptimize
1815   nm->make_not_entrant(nmethod::InvalidationReason::MISSING_EXCEPTION_HANDLER);
1816 
1817   // Use Deoptimization::deoptimize for all of its side-effects:
1818   // gathering traps statistics, logging...
1819   // it also patches the return pc but we do not care about that
1820   // since we return a continuation to the deopt_blob below.
1821   JavaThread* thread = JavaThread::current();
1822   RegisterMap reg_map(thread,
1823                       RegisterMap::UpdateMap::skip,
1824                       RegisterMap::ProcessFrames::include,
1825                       RegisterMap::WalkContinuation::skip);
1826   frame runtime_frame = thread->last_frame();
1827   frame caller_frame = runtime_frame.sender(&reg_map);
1828   assert(caller_frame.cb()->as_nmethod_or_null() == nm, "expect top frame compiled method");
1829   vframe* vf = vframe::new_vframe(&caller_frame, &reg_map, thread);
1830   compiledVFrame* cvf = compiledVFrame::cast(vf);
1831   ScopeDesc* imm_scope = cvf->scope();
1832   MethodData* imm_mdo = get_method_data(thread, methodHandle(thread, imm_scope->method()), true);
1833   if (imm_mdo != nullptr) {
1834     // Lock to read ProfileData, and ensure lock is not broken by a safepoint
1835     MutexLocker ml(imm_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
1836 
1837     ProfileData* pdata = imm_mdo->allocate_bci_to_data(imm_scope->bci(), nullptr);
1838     if (pdata != nullptr && pdata->is_BitData()) {
1839       BitData* bit_data = (BitData*) pdata;
1840       bit_data->set_exception_seen();
1841     }
1842   }
1843 
1844   Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1845 
1846   MethodData* trap_mdo = get_method_data(thread, methodHandle(thread, nm->method()), true);
1847   if (trap_mdo != nullptr) {
1848     trap_mdo->inc_trap_count(Deoptimization::Reason_not_compiled_exception_handler);
1849   }
1850 
1851   return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1852 }
1853 #endif
1854 
1855 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1856   assert(thread == Thread::current() ||
1857          thread->is_handshake_safe_for(Thread::current()) ||
1858          SafepointSynchronize::is_at_safepoint(),
1859          "can only deoptimize other thread at a safepoint/handshake");
1860   // Compute frame and register map based on thread and sp.
1861   RegisterMap reg_map(thread,
1862                       RegisterMap::UpdateMap::skip,
1863                       RegisterMap::ProcessFrames::include,
1864                       RegisterMap::WalkContinuation::skip);
1865   frame fr = thread->last_frame();
1866   while (fr.id() != id) {
1867     fr = fr.sender(&reg_map);
1868   }
1869   deoptimize(thread, fr, reason);
1870 }
1871 
1872 
1873 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1874   Thread* current = Thread::current();
1875   if (thread == current || thread->is_handshake_safe_for(current)) {
1876     Deoptimization::deoptimize_frame_internal(thread, id, reason);
1877   } else {
1878     VM_DeoptimizeFrame deopt(thread, id, reason);
1879     VMThread::execute(&deopt);
1880   }
1881 }
1882 
1883 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1884   deoptimize_frame(thread, id, Reason_constraint);
1885 }
1886 
1887 // JVMTI PopFrame support
1888 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1889 {
1890   assert(thread == JavaThread::current(), "pre-condition");
1891   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1892 }
1893 JRT_END
1894 
1895 MethodData*
1896 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1897                                 bool create_if_missing) {
1898   JavaThread* THREAD = thread; // For exception macros.
1899   MethodData* mdo = m()->method_data();
1900   if (mdo == nullptr && create_if_missing && !HAS_PENDING_EXCEPTION) {
1901     // Build an MDO.  Ignore errors like OutOfMemory;
1902     // that simply means we won't have an MDO to update.
1903     Method::build_profiling_method_data(m, THREAD);
1904     if (HAS_PENDING_EXCEPTION) {
1905       // Only metaspace OOM is expected. No Java code executed.
1906       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1907       CLEAR_PENDING_EXCEPTION;
1908     }
1909     mdo = m()->method_data();
1910   }
1911   return mdo;
1912 }
1913 
1914 #if COMPILER2_OR_JVMCI
1915 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1916   // In case of an unresolved klass entry, load the class.
1917   // This path is exercised from case _ldc in Parse::do_one_bytecode,
1918   // and probably nowhere else.
1919   // Even that case would benefit from simply re-interpreting the
1920   // bytecode, without paying special attention to the class index.
1921   // So this whole "class index" feature should probably be removed.
1922 
1923   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1924     Klass* tk = constant_pool->klass_at(index, THREAD);
1925     if (HAS_PENDING_EXCEPTION) {
1926       // Exception happened during classloading. We ignore the exception here, since it
1927       // is going to be rethrown since the current activation is going to be deoptimized and
1928       // the interpreter will re-execute the bytecode.
1929       // Do not clear probable Async Exceptions.
1930       CLEAR_PENDING_NONASYNC_EXCEPTION;
1931       // Class loading called java code which may have caused a stack
1932       // overflow. If the exception was thrown right before the return
1933       // to the runtime the stack is no longer guarded. Reguard the
1934       // stack otherwise if we return to the uncommon trap blob and the
1935       // stack bang causes a stack overflow we crash.
1936       JavaThread* jt = THREAD;
1937       bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1938       assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1939     }
1940     return;
1941   }
1942 
1943   assert(!constant_pool->tag_at(index).is_symbol(),
1944          "no symbolic names here, please");
1945 }
1946 
1947 #if INCLUDE_JFR
1948 
1949 class DeoptReasonSerializer : public JfrSerializer {
1950  public:
1951   void serialize(JfrCheckpointWriter& writer) {
1952     writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
1953     for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
1954       writer.write_key((u8)i);
1955       writer.write(Deoptimization::trap_reason_name(i));
1956     }
1957   }
1958 };
1959 
1960 class DeoptActionSerializer : public JfrSerializer {
1961  public:
1962   void serialize(JfrCheckpointWriter& writer) {
1963     static const u4 nof_actions = Deoptimization::Action_LIMIT;
1964     writer.write_count(nof_actions);
1965     for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
1966       writer.write_key(i);
1967       writer.write(Deoptimization::trap_action_name((int)i));
1968     }
1969   }
1970 };
1971 
1972 static void register_serializers() {
1973   static int critical_section = 0;
1974   if (1 == critical_section || AtomicAccess::cmpxchg(&critical_section, 0, 1) == 1) {
1975     return;
1976   }
1977   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
1978   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
1979 }
1980 
1981 static void post_deoptimization_event(nmethod* nm,
1982                                       const Method* method,
1983                                       int trap_bci,
1984                                       int instruction,
1985                                       Deoptimization::DeoptReason reason,
1986                                       Deoptimization::DeoptAction action) {
1987   assert(nm != nullptr, "invariant");
1988   assert(method != nullptr, "invariant");
1989   if (EventDeoptimization::is_enabled()) {
1990     static bool serializers_registered = false;
1991     if (!serializers_registered) {
1992       register_serializers();
1993       serializers_registered = true;
1994     }
1995     EventDeoptimization event;
1996     event.set_compileId(nm->compile_id());
1997     event.set_compiler(nm->compiler_type());
1998     event.set_method(method);
1999     event.set_lineNumber(method->line_number_from_bci(trap_bci));
2000     event.set_bci(trap_bci);
2001     event.set_instruction(instruction);
2002     event.set_reason(reason);
2003     event.set_action(action);
2004     event.commit();
2005   }
2006 }
2007 
2008 #endif // INCLUDE_JFR
2009 
2010 static void log_deopt(nmethod* nm, Method* tm, intptr_t pc, frame& fr, int trap_bci,
2011                               const char* reason_name, const char* reason_action) {
2012   LogTarget(Debug, deoptimization) lt;
2013   if (lt.is_enabled()) {
2014     LogStream ls(lt);
2015     bool is_osr = nm->is_osr_method();
2016     ls.print("cid=%4d %s%s%s level=%d",
2017              nm->compile_id(), (is_osr ? "osr" : "   "),
2018              (nm->is_aot() ? "aot " : ""),
2019              (nm->preloaded() ? "preload " : ""),
2020              nm->comp_level());
2021     ls.print(" %s", tm->name_and_sig_as_C_string());
2022     ls.print(" trap_bci=%d ", trap_bci);
2023     if (is_osr) {
2024       ls.print("osr_bci=%d ", nm->osr_entry_bci());
2025     }
2026     ls.print("%s ", reason_name);
2027     ls.print("%s ", reason_action);
2028     ls.print_cr("pc=" INTPTR_FORMAT " relative_pc=" INTPTR_FORMAT,
2029              pc, fr.pc() - nm->code_begin());
2030   }
2031 }
2032 
2033 JRT_ENTRY_PROF(void, Deoptimization, uncommon_trap_inner, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
2034   HandleMark hm(current);
2035 
2036   // uncommon_trap() is called at the beginning of the uncommon trap
2037   // handler. Note this fact before we start generating temporary frames
2038   // that can confuse an asynchronous stack walker. This counter is
2039   // decremented at the end of unpack_frames().
2040 
2041   current->inc_in_deopt_handler();
2042 
2043 #if INCLUDE_JVMCI
2044   // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
2045   RegisterMap reg_map(current,
2046                       RegisterMap::UpdateMap::include,
2047                       RegisterMap::ProcessFrames::include,
2048                       RegisterMap::WalkContinuation::skip);
2049 #else
2050   RegisterMap reg_map(current,
2051                       RegisterMap::UpdateMap::skip,
2052                       RegisterMap::ProcessFrames::include,
2053                       RegisterMap::WalkContinuation::skip);
2054 #endif
2055   frame stub_frame = current->last_frame();
2056   frame fr = stub_frame.sender(&reg_map);
2057 
2058   // Log a message
2059   Events::log_deopt_message(current, "Uncommon trap: trap_request=" INT32_FORMAT_X_0 " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
2060               trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
2061 
2062   {
2063     ResourceMark rm;
2064 
2065     DeoptReason reason = trap_request_reason(trap_request);
2066     DeoptAction action = trap_request_action(trap_request);
2067 #if INCLUDE_JVMCI
2068     int debug_id = trap_request_debug_id(trap_request);
2069 #endif
2070     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
2071 
2072     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, current);
2073     compiledVFrame* cvf = compiledVFrame::cast(vf);
2074 
2075     nmethod* nm = cvf->code();
2076 
2077     ScopeDesc*      trap_scope  = cvf->scope();
2078 
2079     bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
2080 
2081     if (is_receiver_constraint_failure) {
2082       tty->print_cr("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"),
2083                     trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
2084                     JVMCI_ONLY(COMMA debug_id));
2085     }
2086 
2087     methodHandle    trap_method(current, trap_scope->method());
2088     int             trap_bci    = trap_scope->bci();
2089 #if INCLUDE_JVMCI
2090     jlong           speculation = current->pending_failed_speculation();
2091     if (nm->is_compiled_by_jvmci()) {
2092       nm->update_speculation(current);
2093     } else {
2094       assert(speculation == 0, "There should not be a speculation for methods compiled by non-JVMCI compilers");
2095     }
2096 
2097     if (trap_bci == SynchronizationEntryBCI) {
2098       trap_bci = 0;
2099       current->set_pending_monitorenter(true);
2100     }
2101 
2102     if (reason == Deoptimization::Reason_transfer_to_interpreter) {
2103       current->set_pending_transfer_to_interpreter(true);
2104     }
2105 #endif
2106 
2107     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
2108     // Record this event in the histogram.
2109     gather_statistics(nm, reason, action, trap_bc);
2110 
2111     // Ensure that we can record deopt. history:
2112     bool create_if_missing = ProfileTraps;
2113 
2114     methodHandle profiled_method;
2115 #if INCLUDE_JVMCI
2116     if (nm->is_compiled_by_jvmci()) {
2117       profiled_method = methodHandle(current, nm->method());
2118     } else {
2119       profiled_method = trap_method;
2120     }
2121 #else
2122     profiled_method = trap_method;
2123 #endif
2124 
2125     const char* nm_kind = nm->compile_kind();
2126     MethodData* trap_mdo =
2127       get_method_data(current, profiled_method, create_if_missing);
2128 
2129     { // Log Deoptimization event for JFR, UL and event system
2130       Method* tm = trap_method();
2131       const char* reason_name = trap_reason_name(reason);
2132       const char* reason_action = trap_action_name(action);
2133       intptr_t pc = p2i(fr.pc());
2134 
2135       JFR_ONLY(post_deoptimization_event(nm, tm, trap_bci, trap_bc, reason, action);)
2136       log_deopt(nm, tm, pc, fr, trap_bci, reason_name, reason_action);
2137       Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s %s",
2138                                 reason_name, reason_action, pc,
2139                                 tm->name_and_sig_as_C_string(), trap_bci, nm->compiler_name(), nm_kind);
2140     }
2141 
2142     // Print a bunch of diagnostics, if requested.
2143     if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
2144       ResourceMark rm;
2145 
2146       // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2147       // We must do this already now, since we cannot acquire this lock while
2148       // holding the tty lock (lock ordering by rank).
2149       MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2150 
2151       ttyLocker ttyl;
2152 
2153       char buf[100];
2154       if (xtty != nullptr) {
2155         xtty->begin_head("uncommon_trap thread='%zu' %s",
2156                          os::current_thread_id(),
2157                          format_trap_request(buf, sizeof(buf), trap_request));
2158 #if INCLUDE_JVMCI
2159         if (speculation != 0) {
2160           xtty->print(" speculation='" JLONG_FORMAT "'", speculation);
2161         }
2162 #endif
2163         nm->log_identity(xtty);
2164       }
2165       Symbol* class_name = nullptr;
2166       bool unresolved = false;
2167       if (unloaded_class_index >= 0) {
2168         constantPoolHandle constants (current, trap_method->constants());
2169         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
2170           class_name = constants->klass_name_at(unloaded_class_index);
2171           unresolved = true;
2172           if (xtty != nullptr)
2173             xtty->print(" unresolved='1'");
2174         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
2175           class_name = constants->symbol_at(unloaded_class_index);
2176         }
2177         if (xtty != nullptr)
2178           xtty->name(class_name);
2179       }
2180       if (xtty != nullptr && trap_mdo != nullptr && (int)reason < (int)MethodData::_trap_hist_limit) {
2181         // Dump the relevant MDO state.
2182         // This is the deopt count for the current reason, any previous
2183         // reasons or recompiles seen at this point.
2184         int dcnt = trap_mdo->trap_count(reason);
2185         if (dcnt != 0)
2186           xtty->print(" count='%d'", dcnt);
2187 
2188         // We need to lock to read the ProfileData. But to keep the locks ordered, we need to
2189         // lock extra_data_lock before the tty lock.
2190         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
2191         int dos = (pdata == nullptr)? 0: pdata->trap_state();
2192         if (dos != 0) {
2193           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
2194           if (trap_state_is_recompiled(dos)) {
2195             int recnt2 = trap_mdo->overflow_recompile_count();
2196             if (recnt2 != 0)
2197               xtty->print(" recompiles2='%d'", recnt2);
2198           }
2199         }
2200       }
2201       if (xtty != nullptr) {
2202         xtty->stamp();
2203         xtty->end_head();
2204       }
2205       if (TraceDeoptimization) {  // make noise on the tty
2206         stringStream st;
2207         st.print("UNCOMMON TRAP method=%s", trap_scope->method()->name_and_sig_as_C_string());
2208         st.print("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT JVMCI_ONLY(", debug_id=%d"),
2209                  trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin() JVMCI_ONLY(COMMA debug_id));
2210         st.print(" compiler=%s compile_id=%d kind=%s", nm->compiler_name(), nm->compile_id(), nm_kind);
2211 #if INCLUDE_JVMCI
2212         if (nm->is_compiled_by_jvmci()) {
2213           const char* installed_code_name = nm->jvmci_name();
2214           if (installed_code_name != nullptr) {
2215             st.print(" (JVMCI: installed code name=%s) ", installed_code_name);
2216           }
2217         }
2218 #endif
2219         st.print(" (@" INTPTR_FORMAT ") thread=%zu reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
2220                    p2i(fr.pc()),
2221                    os::current_thread_id(),
2222                    trap_reason_name(reason),
2223                    trap_action_name(action),
2224                    unloaded_class_index
2225 #if INCLUDE_JVMCI
2226                    , debug_id
2227 #endif
2228                    );
2229         if (class_name != nullptr) {
2230           st.print(unresolved ? " unresolved class: " : " symbol: ");
2231           class_name->print_symbol_on(&st);
2232         }
2233         st.cr();
2234         tty->print_raw(st.freeze());
2235       }
2236       if (xtty != nullptr) {
2237         // Log the precise location of the trap.
2238         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2239           xtty->begin_elem("jvms bci='%d'", sd->bci());
2240           xtty->method(sd->method());
2241           xtty->end_elem();
2242           if (sd->is_top())  break;
2243         }
2244         xtty->tail("uncommon_trap");
2245       }
2246     }
2247     // (End diagnostic printout.)
2248 
2249     if (is_receiver_constraint_failure) {
2250       fatal("missing receiver type check");
2251     }
2252 
2253     // Load class if necessary
2254     if (unloaded_class_index >= 0) {
2255       constantPoolHandle constants(current, trap_method->constants());
2256       load_class_by_index(constants, unloaded_class_index, THREAD);
2257     }
2258 
2259     // Flush the nmethod if necessary and desirable.
2260     //
2261     // We need to avoid situations where we are re-flushing the nmethod
2262     // because of a hot deoptimization site.  Repeated flushes at the same
2263     // point need to be detected by the compiler and avoided.  If the compiler
2264     // cannot avoid them (or has a bug and "refuses" to avoid them), this
2265     // module must take measures to avoid an infinite cycle of recompilation
2266     // and deoptimization.  There are several such measures:
2267     //
2268     //   1. If a recompilation is ordered a second time at some site X
2269     //   and for the same reason R, the action is adjusted to 'reinterpret',
2270     //   to give the interpreter time to exercise the method more thoroughly.
2271     //   If this happens, the method's overflow_recompile_count is incremented.
2272     //
2273     //   2. If the compiler fails to reduce the deoptimization rate, then
2274     //   the method's overflow_recompile_count will begin to exceed the set
2275     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
2276     //   is adjusted to 'make_not_compilable', and the method is abandoned
2277     //   to the interpreter.  This is a performance hit for hot methods,
2278     //   but is better than a disastrous infinite cycle of recompilations.
2279     //   (Actually, only the method containing the site X is abandoned.)
2280     //
2281     //   3. In parallel with the previous measures, if the total number of
2282     //   recompilations of a method exceeds the much larger set limit
2283     //   PerMethodRecompilationCutoff, the method is abandoned.
2284     //   This should only happen if the method is very large and has
2285     //   many "lukewarm" deoptimizations.  The code which enforces this
2286     //   limit is elsewhere (class nmethod, class Method).
2287     //
2288     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2289     // to recompile at each bytecode independently of the per-BCI cutoff.
2290     //
2291     // The decision to update code is up to the compiler, and is encoded
2292     // in the Action_xxx code.  If the compiler requests Action_none
2293     // no trap state is changed, no compiled code is changed, and the
2294     // computation suffers along in the interpreter.
2295     //
2296     // The other action codes specify various tactics for decompilation
2297     // and recompilation.  Action_maybe_recompile is the loosest, and
2298     // allows the compiled code to stay around until enough traps are seen,
2299     // and until the compiler gets around to recompiling the trapping method.
2300     //
2301     // The other actions cause immediate removal of the present code.
2302 
2303     // Traps caused by injected profile shouldn't pollute trap counts.
2304     bool injected_profile_trap = trap_method->has_injected_profile() &&
2305                                  (reason == Reason_intrinsic || reason == Reason_unreached);
2306 
2307     bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2308     bool make_not_entrant = false;
2309     bool make_not_compilable = false;
2310     bool reprofile = false;
2311     switch (action) {
2312     case Action_none:
2313       // Keep the old code.
2314       update_trap_state = false;
2315       break;
2316     case Action_maybe_recompile:
2317       // Do not need to invalidate the present code, but we can
2318       // initiate another
2319       // Start compiler without (necessarily) invalidating the nmethod.
2320       // The system will tolerate the old code, but new code should be
2321       // generated when possible.
2322       break;
2323     case Action_reinterpret:
2324       // Go back into the interpreter for a while, and then consider
2325       // recompiling form scratch.
2326       make_not_entrant = true;
2327       // Reset invocation counter for outer most method.
2328       // This will allow the interpreter to exercise the bytecodes
2329       // for a while before recompiling.
2330       // By contrast, Action_make_not_entrant is immediate.
2331       //
2332       // Note that the compiler will track null_check, null_assert,
2333       // range_check, and class_check events and log them as if they
2334       // had been traps taken from compiled code.  This will update
2335       // the MDO trap history so that the next compilation will
2336       // properly detect hot trap sites.
2337       reprofile = true;
2338       break;
2339     case Action_make_not_entrant:
2340       // Request immediate recompilation, and get rid of the old code.
2341       // Make them not entrant, so next time they are called they get
2342       // recompiled.  Unloaded classes are loaded now so recompile before next
2343       // time they are called.  Same for uninitialized.  The interpreter will
2344       // link the missing class, if any.
2345       make_not_entrant = true;
2346       break;
2347     case Action_make_not_compilable:
2348       // Give up on compiling this method at all.
2349       make_not_entrant = true;
2350       make_not_compilable = true;
2351       break;
2352     default:
2353       ShouldNotReachHere();
2354     }
2355 
2356 #if INCLUDE_JVMCI
2357     // Deoptimization count is used by the CompileBroker to reason about compilations
2358     // it requests so do not pollute the count for deoptimizations in non-default (i.e.
2359     // non-CompilerBroker) compilations.
2360     if (nm->jvmci_skip_profile_deopt()) {
2361       update_trap_state = false;
2362     }
2363 #endif
2364     // Setting +ProfileTraps fixes the following, on all platforms:
2365     // The result is infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2366     // recompile relies on a MethodData* to record heroic opt failures.
2367 
2368     // Whether the interpreter is producing MDO data or not, we also need
2369     // to use the MDO to detect hot deoptimization points and control
2370     // aggressive optimization.
2371     bool inc_recompile_count = false;
2372 
2373     // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2374     ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
2375                               (trap_mdo != nullptr),
2376                               Mutex::_no_safepoint_check_flag);
2377     ProfileData* pdata = nullptr;
2378     if (ProfileTraps && CompilerConfig::is_c2_or_jvmci_compiler_enabled() && update_trap_state && trap_mdo != nullptr) {
2379       assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2380       uint this_trap_count = 0;
2381       bool maybe_prior_trap = false;
2382       bool maybe_prior_recompile = false;
2383 
2384       pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
2385 #if INCLUDE_JVMCI
2386                                    nm->is_compiled_by_jvmci() && nm->is_osr_method(),
2387 #endif
2388                                    nm->method(),
2389                                    //outputs:
2390                                    this_trap_count,
2391                                    maybe_prior_trap,
2392                                    maybe_prior_recompile);
2393       // Because the interpreter also counts null, div0, range, and class
2394       // checks, these traps from compiled code are double-counted.
2395       // This is harmless; it just means that the PerXTrapLimit values
2396       // are in effect a little smaller than they look.
2397 
2398       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2399       if (per_bc_reason != Reason_none) {
2400         // Now take action based on the partially known per-BCI history.
2401         if (maybe_prior_trap
2402             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2403           // If there are too many traps at this BCI, force a recompile.
2404           // This will allow the compiler to see the limit overflow, and
2405           // take corrective action, if possible.  The compiler generally
2406           // does not use the exact PerBytecodeTrapLimit value, but instead
2407           // changes its tactics if it sees any traps at all.  This provides
2408           // a little hysteresis, delaying a recompile until a trap happens
2409           // several times.
2410           //
2411           // Actually, since there is only one bit of counter per BCI,
2412           // the possible per-BCI counts are {0,1,(per-method count)}.
2413           // This produces accurate results if in fact there is only
2414           // one hot trap site, but begins to get fuzzy if there are
2415           // many sites.  For example, if there are ten sites each
2416           // trapping two or more times, they each get the blame for
2417           // all of their traps.
2418           make_not_entrant = true;
2419         }
2420 
2421         // Detect repeated recompilation at the same BCI, and enforce a limit.
2422         if (make_not_entrant && maybe_prior_recompile) {
2423           // More than one recompile at this point.
2424           inc_recompile_count = maybe_prior_trap;
2425         }
2426       } else {
2427         // For reasons which are not recorded per-bytecode, we simply
2428         // force recompiles unconditionally.
2429         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2430         make_not_entrant = true;
2431       }
2432 
2433       // Go back to the compiler if there are too many traps in this method.
2434       if (this_trap_count >= per_method_trap_limit(reason)) {
2435         // If there are too many traps in this method, force a recompile.
2436         // This will allow the compiler to see the limit overflow, and
2437         // take corrective action, if possible.
2438         // (This condition is an unlikely backstop only, because the
2439         // PerBytecodeTrapLimit is more likely to take effect first,
2440         // if it is applicable.)
2441         make_not_entrant = true;
2442       }
2443 
2444       // Here's more hysteresis:  If there has been a recompile at
2445       // this trap point already, run the method in the interpreter
2446       // for a while to exercise it more thoroughly.
2447       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2448         reprofile = true;
2449       }
2450     }
2451 
2452     // Take requested actions on the method:
2453 
2454     // Recompile
2455     if (make_not_entrant) {
2456       if (!nm->make_not_entrant(nmethod::InvalidationReason::UNCOMMON_TRAP)) {
2457         return; // the call did not change nmethod's state
2458       }
2459 
2460       if (pdata != nullptr) {
2461         // Record the recompilation event, if any.
2462         int tstate0 = pdata->trap_state();
2463         int tstate1 = trap_state_set_recompiled(tstate0, true);
2464         if (tstate1 != tstate0)
2465           pdata->set_trap_state(tstate1);
2466       }
2467 
2468       // For code aging we count traps separately here, using make_not_entrant()
2469       // as a guard against simultaneous deopts in multiple threads.
2470       if (reason == Reason_tenured && trap_mdo != nullptr) {
2471         trap_mdo->inc_tenure_traps();
2472       }
2473     }
2474     if (inc_recompile_count) {
2475       trap_mdo->inc_overflow_recompile_count();
2476       if ((uint)trap_mdo->overflow_recompile_count() >
2477           (uint)PerBytecodeRecompilationCutoff) {
2478         // Give up on the method containing the bad BCI.
2479         if (trap_method() == nm->method()) {
2480           make_not_compilable = true;
2481         } else {
2482           trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2483           // But give grace to the enclosing nm->method().
2484         }
2485       }
2486     }
2487 
2488     // Reprofile
2489     if (reprofile) {
2490       CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2491     }
2492 
2493     // Give up compiling
2494     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2495       assert(make_not_entrant, "consistent");
2496       nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2497     }
2498 
2499     if (ProfileExceptionHandlers && trap_mdo != nullptr) {
2500       BitData* exception_handler_data = trap_mdo->exception_handler_bci_to_data_or_null(trap_bci);
2501       if (exception_handler_data != nullptr) {
2502         // uncommon trap at the start of an exception handler.
2503         // C2 generates these for un-entered exception handlers.
2504         // mark the handler as entered to avoid generating
2505         // another uncommon trap the next time the handler is compiled
2506         exception_handler_data->set_exception_handler_entered();
2507       }
2508     }
2509 
2510   } // Free marked resources
2511 
2512 }
2513 JRT_END
2514 
2515 ProfileData*
2516 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2517                                          int trap_bci,
2518                                          Deoptimization::DeoptReason reason,
2519                                          bool update_total_trap_count,
2520 #if INCLUDE_JVMCI
2521                                          bool is_osr,
2522 #endif
2523                                          Method* compiled_method,
2524                                          //outputs:
2525                                          uint& ret_this_trap_count,
2526                                          bool& ret_maybe_prior_trap,
2527                                          bool& ret_maybe_prior_recompile) {
2528   trap_mdo->check_extra_data_locked();
2529 
2530   bool maybe_prior_trap = false;
2531   bool maybe_prior_recompile = false;
2532   uint this_trap_count = 0;
2533   if (update_total_trap_count) {
2534     uint idx = reason;
2535 #if INCLUDE_JVMCI
2536     if (is_osr) {
2537       // Upper half of history array used for traps in OSR compilations
2538       idx += Reason_TRAP_HISTORY_LENGTH;
2539     }
2540 #endif
2541     uint prior_trap_count = trap_mdo->trap_count(idx);
2542     this_trap_count  = trap_mdo->inc_trap_count(idx);
2543 
2544     // If the runtime cannot find a place to store trap history,
2545     // it is estimated based on the general condition of the method.
2546     // If the method has ever been recompiled, or has ever incurred
2547     // a trap with the present reason , then this BCI is assumed
2548     // (pessimistically) to be the culprit.
2549     maybe_prior_trap      = (prior_trap_count != 0);
2550     maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2551   }
2552   ProfileData* pdata = nullptr;
2553 
2554 
2555   // For reasons which are recorded per bytecode, we check per-BCI data.
2556   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2557   assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
2558   if (per_bc_reason != Reason_none) {
2559     // Find the profile data for this BCI.  If there isn't one,
2560     // try to allocate one from the MDO's set of spares.
2561     // This will let us detect a repeated trap at this point.
2562     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : nullptr);
2563 
2564     if (pdata != nullptr) {
2565       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2566         if (LogCompilation && xtty != nullptr) {
2567           ttyLocker ttyl;
2568           // no more room for speculative traps in this MDO
2569           xtty->elem("speculative_traps_oom");
2570         }
2571       }
2572       // Query the trap state of this profile datum.
2573       int tstate0 = pdata->trap_state();
2574       if (!trap_state_has_reason(tstate0, per_bc_reason))
2575         maybe_prior_trap = false;
2576       if (!trap_state_is_recompiled(tstate0))
2577         maybe_prior_recompile = false;
2578 
2579       // Update the trap state of this profile datum.
2580       int tstate1 = tstate0;
2581       // Record the reason.
2582       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2583       // Store the updated state on the MDO, for next time.
2584       if (tstate1 != tstate0)
2585         pdata->set_trap_state(tstate1);
2586     } else {
2587       if (LogCompilation && xtty != nullptr) {
2588         ttyLocker ttyl;
2589         // Missing MDP?  Leave a small complaint in the log.
2590         xtty->elem("missing_mdp bci='%d'", trap_bci);
2591       }
2592     }
2593   }
2594 
2595   // Return results:
2596   ret_this_trap_count = this_trap_count;
2597   ret_maybe_prior_trap = maybe_prior_trap;
2598   ret_maybe_prior_recompile = maybe_prior_recompile;
2599   return pdata;
2600 }
2601 
2602 void
2603 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2604   ResourceMark rm;
2605   // Ignored outputs:
2606   uint ignore_this_trap_count;
2607   bool ignore_maybe_prior_trap;
2608   bool ignore_maybe_prior_recompile;
2609   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2610   // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2611   bool update_total_counts = true JVMCI_ONLY( && !UseJVMCICompiler);
2612 
2613   // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2614   MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2615 
2616   query_update_method_data(trap_mdo, trap_bci,
2617                            (DeoptReason)reason,
2618                            update_total_counts,
2619 #if INCLUDE_JVMCI
2620                            false,
2621 #endif
2622                            nullptr,
2623                            ignore_this_trap_count,
2624                            ignore_maybe_prior_trap,
2625                            ignore_maybe_prior_recompile);
2626 }
2627 
2628 PROF_ENTRY(Deoptimization::UnrollBlock*, Deoptimization, uncommon_trap, Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode))
2629   // Enable WXWrite: current function is called from methods compiled by C2 directly
2630   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2631 
2632   // Still in Java no safepoints
2633   {
2634     // This enters VM and may safepoint
2635     uncommon_trap_inner(current, trap_request);
2636   }
2637   HandleMark hm(current);
2638   return fetch_unroll_info_helper(current, exec_mode);
2639 PROF_END
2640 
2641 // Local derived constants.
2642 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2643 const int DS_REASON_MASK   = ((uint)DataLayout::trap_mask) >> 1;
2644 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2645 
2646 //---------------------------trap_state_reason---------------------------------
2647 Deoptimization::DeoptReason
2648 Deoptimization::trap_state_reason(int trap_state) {
2649   // This assert provides the link between the width of DataLayout::trap_bits
2650   // and the encoding of "recorded" reasons.  It ensures there are enough
2651   // bits to store all needed reasons in the per-BCI MDO profile.
2652   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2653   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2654   trap_state -= recompile_bit;
2655   if (trap_state == DS_REASON_MASK) {
2656     return Reason_many;
2657   } else {
2658     assert((int)Reason_none == 0, "state=0 => Reason_none");
2659     return (DeoptReason)trap_state;
2660   }
2661 }
2662 //-------------------------trap_state_has_reason-------------------------------
2663 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2664   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2665   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2666   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2667   trap_state -= recompile_bit;
2668   if (trap_state == DS_REASON_MASK) {
2669     return -1;  // true, unspecifically (bottom of state lattice)
2670   } else if (trap_state == reason) {
2671     return 1;   // true, definitely
2672   } else if (trap_state == 0) {
2673     return 0;   // false, definitely (top of state lattice)
2674   } else {
2675     return 0;   // false, definitely
2676   }
2677 }
2678 //-------------------------trap_state_add_reason-------------------------------
2679 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2680   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2681   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2682   trap_state -= recompile_bit;
2683   if (trap_state == DS_REASON_MASK) {
2684     return trap_state + recompile_bit;     // already at state lattice bottom
2685   } else if (trap_state == reason) {
2686     return trap_state + recompile_bit;     // the condition is already true
2687   } else if (trap_state == 0) {
2688     return reason + recompile_bit;          // no condition has yet been true
2689   } else {
2690     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
2691   }
2692 }
2693 //-----------------------trap_state_is_recompiled------------------------------
2694 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2695   return (trap_state & DS_RECOMPILE_BIT) != 0;
2696 }
2697 //-----------------------trap_state_set_recompiled-----------------------------
2698 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2699   if (z)  return trap_state |  DS_RECOMPILE_BIT;
2700   else    return trap_state & ~DS_RECOMPILE_BIT;
2701 }
2702 //---------------------------format_trap_state---------------------------------
2703 // This is used for debugging and diagnostics, including LogFile output.
2704 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2705                                               int trap_state) {
2706   assert(buflen > 0, "sanity");
2707   DeoptReason reason      = trap_state_reason(trap_state);
2708   bool        recomp_flag = trap_state_is_recompiled(trap_state);
2709   // Re-encode the state from its decoded components.
2710   int decoded_state = 0;
2711   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2712     decoded_state = trap_state_add_reason(decoded_state, reason);
2713   if (recomp_flag)
2714     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2715   // If the state re-encodes properly, format it symbolically.
2716   // Because this routine is used for debugging and diagnostics,
2717   // be robust even if the state is a strange value.
2718   size_t len;
2719   if (decoded_state != trap_state) {
2720     // Random buggy state that doesn't decode??
2721     len = jio_snprintf(buf, buflen, "#%d", trap_state);
2722   } else {
2723     len = jio_snprintf(buf, buflen, "%s%s",
2724                        trap_reason_name(reason),
2725                        recomp_flag ? " recompiled" : "");
2726   }
2727   return buf;
2728 }
2729 
2730 
2731 //--------------------------------statics--------------------------------------
2732 const char* Deoptimization::_trap_reason_name[] = {
2733   // Note:  Keep this in sync. with enum DeoptReason.
2734   "none",
2735   "null_check",
2736   "null_assert" JVMCI_ONLY("_or_unreached0"),
2737   "range_check",
2738   "class_check",
2739   "array_check",
2740   "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2741   "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2742   "profile_predicate",
2743   "auto_vectorization_check",
2744   "unloaded",
2745   "uninitialized",
2746   "initialized",
2747   "unreached",
2748   "unhandled",
2749   "constraint",
2750   "div0_check",
2751   "age",
2752   "predicate",
2753   "loop_limit_check",
2754   "speculate_class_check",
2755   "speculate_null_check",
2756   "speculate_null_assert",
2757   "unstable_if",
2758   "unstable_fused_if",
2759   "receiver_constraint",
2760   "short_running_loop" JVMCI_ONLY("_or_aliasing"),
2761 #if INCLUDE_JVMCI
2762   "transfer_to_interpreter",
2763   "not_compiled_exception_handler",
2764   "unresolved",
2765   "jsr_mismatch",
2766 #endif
2767   "tenured"
2768 };
2769 const char* Deoptimization::_trap_action_name[] = {
2770   // Note:  Keep this in sync. with enum DeoptAction.
2771   "none",
2772   "maybe_recompile",
2773   "reinterpret",
2774   "make_not_entrant",
2775   "make_not_compilable"
2776 };
2777 
2778 const char* Deoptimization::trap_reason_name(int reason) {
2779   // Check that every reason has a name
2780   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2781 
2782   if (reason == Reason_many)  return "many";
2783   if ((uint)reason < Reason_LIMIT)
2784     return _trap_reason_name[reason];
2785   static char buf[20];
2786   os::snprintf_checked(buf, sizeof(buf), "reason%d", reason);
2787   return buf;
2788 }
2789 const char* Deoptimization::trap_action_name(int action) {
2790   // Check that every action has a name
2791   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2792 
2793   if ((uint)action < Action_LIMIT)
2794     return _trap_action_name[action];
2795   static char buf[20];
2796   os::snprintf_checked(buf, sizeof(buf), "action%d", action);
2797   return buf;
2798 }
2799 
2800 // This is used for debugging and diagnostics, including LogFile output.
2801 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2802                                                 int trap_request) {
2803   jint unloaded_class_index = trap_request_index(trap_request);
2804   const char* reason = trap_reason_name(trap_request_reason(trap_request));
2805   const char* action = trap_action_name(trap_request_action(trap_request));
2806 #if INCLUDE_JVMCI
2807   int debug_id = trap_request_debug_id(trap_request);
2808 #endif
2809   size_t len;
2810   if (unloaded_class_index < 0) {
2811     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2812                        reason, action
2813 #if INCLUDE_JVMCI
2814                        ,debug_id
2815 #endif
2816                        );
2817   } else {
2818     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2819                        reason, action, unloaded_class_index
2820 #if INCLUDE_JVMCI
2821                        ,debug_id
2822 #endif
2823                        );
2824   }
2825   return buf;
2826 }
2827 
2828 juint Deoptimization::_deoptimization_hist
2829         [1 + 4 + 5] // total + online + archived
2830         [Deoptimization::Reason_LIMIT]
2831     [1 + Deoptimization::Action_LIMIT]
2832         [Deoptimization::BC_CASE_LIMIT]
2833   = {0};
2834 
2835 enum {
2836   LSB_BITS = 8,
2837   LSB_MASK = right_n_bits(LSB_BITS)
2838 };
2839 
2840 static void update(juint* cases, Bytecodes::Code bc) {
2841   juint* bc_counter_addr = nullptr;
2842   juint  bc_counter      = 0;
2843   // Look for an unused counter, or an exact match to this BC.
2844   if (bc != Bytecodes::_illegal) {
2845     for (int bc_case = 0; bc_case < Deoptimization::BC_CASE_LIMIT; bc_case++) {
2846       juint* counter_addr = &cases[bc_case];
2847       juint  counter = *counter_addr;
2848       if ((counter == 0 && bc_counter_addr == nullptr)
2849           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2850         // this counter is either free or is already devoted to this BC
2851         bc_counter_addr = counter_addr;
2852         bc_counter = counter | bc;
2853       }
2854     }
2855   }
2856   if (bc_counter_addr == nullptr) {
2857     // Overflow, or no given bytecode.
2858     bc_counter_addr = &cases[Deoptimization::BC_CASE_LIMIT-1];
2859     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
2860   }
2861   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2862 }
2863 
2864 
2865 void Deoptimization::gather_statistics(nmethod* nm, DeoptReason reason, DeoptAction action,
2866                                        Bytecodes::Code bc) {
2867   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2868   assert(action >= 0 && action < Action_LIMIT, "oob");
2869   _deoptimization_hist[0][Reason_none][0][0] += 1;  // total
2870   _deoptimization_hist[0][reason][0][0]      += 1;  // per-reason total
2871 
2872   update(_deoptimization_hist[0][reason][1+action], bc);
2873 
2874   uint lvl = nm->comp_level() + (nm->is_aot() ? 4 : 0) + (nm->preloaded() ? 1 : 0);
2875   _deoptimization_hist[lvl][Reason_none][0][0] += 1;  // total
2876   _deoptimization_hist[lvl][reason][0][0]      += 1;  // per-reason total
2877   update(_deoptimization_hist[lvl][reason][1+action], bc);
2878 }
2879 
2880 jint Deoptimization::total_deoptimization_count() {
2881   return _deoptimization_hist[0][Reason_none][0][0];
2882 }
2883 
2884 // Get the deopt count for a specific reason and a specific action. If either
2885 // one of 'reason' or 'action' is null, the method returns the sum of all
2886 // deoptimizations with the specific 'action' or 'reason' respectively.
2887 // If both arguments are null, the method returns the total deopt count.
2888 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2889   if (reason_str == nullptr && action_str == nullptr) {
2890     return total_deoptimization_count();
2891   }
2892   juint counter = 0;
2893   for (int reason = 0; reason < Reason_LIMIT; reason++) {
2894     if (reason_str == nullptr || !strcmp(reason_str, trap_reason_name(reason))) {
2895       for (int action = 0; action < Action_LIMIT; action++) {
2896         if (action_str == nullptr || !strcmp(action_str, trap_action_name(action))) {
2897           juint* cases = _deoptimization_hist[0][reason][1+action];
2898           for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2899             counter += cases[bc_case] >> LSB_BITS;
2900           }
2901         }
2902       }
2903     }
2904   }
2905   return counter;
2906 }
2907 
2908 void Deoptimization::print_statistics() {
2909   ttyLocker ttyl;
2910   if (xtty != nullptr)  xtty->head("statistics type='deoptimization'");
2911   tty->print_cr("Deoptimization traps recorded:");
2912   print_statistics_on(tty);
2913   if (xtty != nullptr)  xtty->tail("statistics");
2914 }
2915 
2916 void Deoptimization::print_statistics_on(const char* title, int lvl, outputStream* st) {
2917   juint total = _deoptimization_hist[lvl][Reason_none][0][0];
2918   juint account = total;
2919 #define PRINT_STAT_LINE(name, r) \
2920       st->print_cr("    %d (%4.1f%%) %s", (int)(r), ((r) == total ? 100.0 : (((r) * 100.0) / total)), name);
2921   if (total > 0) {
2922     st->print("  %s: ", title);
2923     PRINT_STAT_LINE("total", total);
2924     // For each non-zero entry in the histogram, print the reason,
2925     // the action, and (if specifically known) the type of bytecode.
2926     for (int reason = 0; reason < Reason_LIMIT; reason++) {
2927       for (int action = 0; action < Action_LIMIT; action++) {
2928         juint* cases = Deoptimization::_deoptimization_hist[lvl][reason][1+action];
2929         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2930           juint counter = cases[bc_case];
2931           if (counter != 0) {
2932             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2933             const char* bc_name = "other";
2934             if (bc_case == (BC_CASE_LIMIT-1) && bc == Bytecodes::_nop) {
2935               // overwritten
2936             } else if (Bytecodes::is_defined(bc)) {
2937               bc_name = Bytecodes::name(bc);
2938             }
2939             juint r = counter >> LSB_BITS;
2940             st->print_cr("    %-34s %16s %16s: " UINT32_FORMAT_W(5) " (%4.1f%%)",
2941                          trap_reason_name(reason), trap_action_name(action), bc_name,
2942                          r, (r * 100.0) / total);
2943             account -= r;
2944           }
2945         }
2946       }
2947     }
2948     if (account != 0) {
2949       PRINT_STAT_LINE("unaccounted", account);
2950     }
2951 #undef PRINT_STAT_LINE
2952   }
2953 }
2954 
2955 void Deoptimization::print_statistics_on(outputStream* st) {
2956 //  print_statistics_on("Total", 0, st);
2957   print_statistics_on("Tier1", 1, st);
2958   print_statistics_on("Tier2", 2, st);
2959   print_statistics_on("Tier3", 3, st);
2960   print_statistics_on("Tier4", 4, st);
2961 
2962   print_statistics_on("AOT Code Tier1", 5, st);
2963   print_statistics_on("AOT Code Tier2", 6, st);
2964   print_statistics_on("AOT Code Tier4", 8, st);
2965   print_statistics_on("AOT Code Tier5 (preloaded)", 9, st);
2966 }
2967 
2968 #define DO_COUNTERS(macro) \
2969   macro(Deoptimization, fetch_unroll_info)   \
2970   macro(Deoptimization, unpack_frames) \
2971   macro(Deoptimization, uncommon_trap_inner) \
2972   macro(Deoptimization, uncommon_trap)
2973 
2974 #define INIT_COUNTER(sub, name) \
2975   NEWPERFTICKCOUNTERS(_perf_##sub##_##name##_timer, SUN_RT, #sub "::" #name) \
2976   NEWPERFEVENTCOUNTER(_perf_##sub##_##name##_count, SUN_RT, #sub "::" #name "_count");
2977 
2978 void Deoptimization::init_counters() {
2979   if (ProfileRuntimeCalls && UsePerfData) {
2980     EXCEPTION_MARK;
2981 
2982     DO_COUNTERS(INIT_COUNTER)
2983 
2984     if (HAS_PENDING_EXCEPTION) {
2985       vm_exit_during_initialization("jvm_perf_init failed unexpectedly");
2986     }
2987   }
2988 }
2989 #undef INIT_COUNTER
2990 
2991 #define PRINT_COUNTER(sub, name) { \
2992   jlong count = _perf_##sub##_##name##_count->get_value(); \
2993   if (count > 0) { \
2994     st->print_cr("  %-50s = " JLONG_FORMAT_W(6) "us (elapsed) " JLONG_FORMAT_W(6) "us (thread) (" JLONG_FORMAT_W(5) " events)", #sub "::" #name, \
2995                  _perf_##sub##_##name##_timer->elapsed_counter_value_us(), \
2996                  _perf_##sub##_##name##_timer->thread_counter_value_us(), \
2997                  count); \
2998   }}
2999 
3000 void Deoptimization::print_counters_on(outputStream* st) {
3001   if (ProfileRuntimeCalls && UsePerfData) {
3002     DO_COUNTERS(PRINT_COUNTER)
3003   } else {
3004     st->print_cr("  Deoptimization: no info (%s is disabled)", (UsePerfData ? "ProfileRuntimeCalls" : "UsePerfData"));
3005   }
3006 }
3007 
3008 #undef PRINT_COUNTER
3009 #undef DO_COUNTERS
3010 
3011 #else // COMPILER2_OR_JVMCI
3012 
3013 
3014 // Stubs for C1 only system.
3015 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
3016   return false;
3017 }
3018 
3019 const char* Deoptimization::trap_reason_name(int reason) {
3020   return "unknown";
3021 }
3022 
3023 jint Deoptimization::total_deoptimization_count() {
3024   return 0;
3025 }
3026 
3027 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
3028   return 0;
3029 }
3030 
3031 void Deoptimization::print_statistics() {
3032   // no output
3033 }
3034 
3035 void
3036 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
3037   // no update
3038 }
3039 
3040 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
3041   return 0;
3042 }
3043 
3044 void Deoptimization::gather_statistics(nmethod* nm, DeoptReason reason, DeoptAction action,
3045                                        Bytecodes::Code bc) {
3046   // no update
3047 }
3048 
3049 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
3050                                               int trap_state) {
3051   jio_snprintf(buf, buflen, "#%d", trap_state);
3052   return buf;
3053 }
3054 
3055 void Deoptimization::init_counters() {
3056   // nothing to do
3057 }
3058 
3059 void Deoptimization::print_counters_on(outputStream* st) {
3060   // no output
3061 }
3062 
3063 void Deoptimization::print_statistics_on(outputStream* st) {
3064   // no output
3065 }
3066 
3067 #endif // COMPILER2_OR_JVMCI