1 /*
   2  * Copyright (c) 1997, 2021, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "jvm.h"
  27 #include "classfile/javaClasses.inline.hpp"
  28 #include "classfile/symbolTable.hpp"
  29 #include "classfile/systemDictionary.hpp"
  30 #include "classfile/vmClasses.hpp"
  31 #include "code/codeCache.hpp"
  32 #include "code/debugInfoRec.hpp"
  33 #include "code/nmethod.hpp"
  34 #include "code/pcDesc.hpp"
  35 #include "code/scopeDesc.hpp"
  36 #include "compiler/compilationPolicy.hpp"
  37 #include "gc/shared/collectedHeap.hpp"
  38 #include "interpreter/bytecode.hpp"
  39 #include "interpreter/interpreter.hpp"
  40 #include "interpreter/oopMapCache.hpp"
  41 #include "memory/allocation.inline.hpp"
  42 #include "memory/oopFactory.hpp"
  43 #include "memory/resourceArea.hpp"
  44 #include "memory/universe.hpp"
  45 #include "oops/constantPool.hpp"
  46 #include "oops/method.hpp"
  47 #include "oops/objArrayKlass.hpp"
  48 #include "oops/objArrayOop.inline.hpp"
  49 #include "oops/oop.inline.hpp"
  50 #include "oops/fieldStreams.inline.hpp"
  51 #include "oops/typeArrayOop.inline.hpp"
  52 #include "oops/verifyOopClosure.hpp"
  53 #include "prims/jvmtiDeferredUpdates.hpp"
  54 #include "prims/jvmtiExport.hpp"
  55 #include "prims/jvmtiThreadState.hpp"
  56 #include "prims/vectorSupport.hpp"
  57 #include "prims/methodHandles.hpp"
  58 #include "runtime/atomic.hpp"
  59 #include "runtime/biasedLocking.hpp"
  60 #include "runtime/deoptimization.hpp"
  61 #include "runtime/escapeBarrier.hpp"
  62 #include "runtime/fieldDescriptor.hpp"
  63 #include "runtime/fieldDescriptor.inline.hpp"
  64 #include "runtime/frame.inline.hpp"
  65 #include "runtime/handles.inline.hpp"
  66 #include "runtime/interfaceSupport.inline.hpp"
  67 #include "runtime/jniHandles.inline.hpp"
  68 #include "runtime/keepStackGCProcessed.hpp"
  69 #include "runtime/objectMonitor.inline.hpp"
  70 #include "runtime/osThread.hpp"
  71 #include "runtime/safepointVerifiers.hpp"
  72 #include "runtime/sharedRuntime.hpp"
  73 #include "runtime/signature.hpp"
  74 #include "runtime/stackFrameStream.inline.hpp"
  75 #include "runtime/stackWatermarkSet.hpp"
  76 #include "runtime/stubRoutines.hpp"
  77 #include "runtime/thread.hpp"
  78 #include "runtime/threadSMR.hpp"
  79 #include "runtime/threadWXSetters.inline.hpp"
  80 #include "runtime/vframe.hpp"
  81 #include "runtime/vframeArray.hpp"
  82 #include "runtime/vframe_hp.hpp"
  83 #include "runtime/vmOperations.hpp"
  84 #include "utilities/events.hpp"
  85 #include "utilities/macros.hpp"
  86 #include "utilities/preserveException.hpp"
  87 #include "utilities/xmlstream.hpp"
  88 #if INCLUDE_JFR
  89 #include "jfr/jfrEvents.hpp"
  90 #include "jfr/metadata/jfrSerializer.hpp"
  91 #endif
  92 
  93 bool DeoptimizationMarker::_is_active = false;
  94 
  95 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
  96                                          int  caller_adjustment,
  97                                          int  caller_actual_parameters,
  98                                          int  number_of_frames,
  99                                          intptr_t* frame_sizes,
 100                                          address* frame_pcs,
 101                                          BasicType return_type,
 102                                          int exec_mode) {
 103   _size_of_deoptimized_frame = size_of_deoptimized_frame;
 104   _caller_adjustment         = caller_adjustment;
 105   _caller_actual_parameters  = caller_actual_parameters;
 106   _number_of_frames          = number_of_frames;
 107   _frame_sizes               = frame_sizes;
 108   _frame_pcs                 = frame_pcs;
 109   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
 110   _return_type               = return_type;
 111   _initial_info              = 0;
 112   // PD (x86 only)
 113   _counter_temp              = 0;
 114   _unpack_kind               = exec_mode;
 115   _sender_sp_temp            = 0;
 116 
 117   _total_frame_sizes         = size_of_frames();
 118   assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
 119 }
 120 
 121 
 122 Deoptimization::UnrollBlock::~UnrollBlock() {
 123   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
 124   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
 125   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
 126 }
 127 
 128 
 129 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
 130   assert(register_number < RegisterMap::reg_count, "checking register number");
 131   return &_register_block[register_number * 2];
 132 }
 133 
 134 
 135 
 136 int Deoptimization::UnrollBlock::size_of_frames() const {
 137   // Acount first for the adjustment of the initial frame
 138   int result = _caller_adjustment;
 139   for (int index = 0; index < number_of_frames(); index++) {
 140     result += frame_sizes()[index];
 141   }
 142   return result;
 143 }
 144 
 145 
 146 void Deoptimization::UnrollBlock::print() {
 147   ttyLocker ttyl;
 148   tty->print_cr("UnrollBlock");
 149   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 150   tty->print(   "  frame_sizes: ");
 151   for (int index = 0; index < number_of_frames(); index++) {
 152     tty->print(INTX_FORMAT " ", frame_sizes()[index]);
 153   }
 154   tty->cr();
 155 }
 156 
 157 
 158 // In order to make fetch_unroll_info work properly with escape
 159 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
 160 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
 161 // which is called from the method fetch_unroll_info_helper below.
 162 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
 163   // fetch_unroll_info() is called at the beginning of the deoptimization
 164   // handler. Note this fact before we start generating temporary frames
 165   // that can confuse an asynchronous stack walker. This counter is
 166   // decremented at the end of unpack_frames().
 167   if (TraceDeoptimization) {
 168     tty->print_cr("Deoptimizing thread " INTPTR_FORMAT, p2i(current));
 169   }
 170   current->inc_in_deopt_handler();
 171 
 172   if (exec_mode == Unpack_exception) {
 173     // When we get here, a callee has thrown an exception into a deoptimized
 174     // frame. That throw might have deferred stack watermark checking until
 175     // after unwinding. So we deal with such deferred requests here.
 176     StackWatermarkSet::after_unwind(current);
 177   }
 178 
 179   return fetch_unroll_info_helper(current, exec_mode);
 180 JRT_END
 181 
 182 #if COMPILER2_OR_JVMCI
 183 static bool rematerialize_objects(JavaThread* thread, int exec_mode, CompiledMethod* compiled_method,
 184                                   frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
 185                                   bool& deoptimized_objects) {
 186   bool realloc_failures = false;
 187   assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 188 
 189   JavaThread* deoptee_thread = chunk->at(0)->thread();
 190   assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
 191          "a frame can only be deoptimized by the owner thread");
 192 
 193   GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 194 
 195   // The flag return_oop() indicates call sites which return oop
 196   // in compiled code. Such sites include java method calls,
 197   // runtime calls (for example, used to allocate new objects/arrays
 198   // on slow code path) and any other calls generated in compiled code.
 199   // It is not guaranteed that we can get such information here only
 200   // by analyzing bytecode in deoptimized frames. This is why this flag
 201   // is set during method compilation (see Compile::Process_OopMap_Node()).
 202   // If the previous frame was popped or if we are dispatching an exception,
 203   // we don't have an oop result.
 204   bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt);
 205   Handle return_value;
 206   if (save_oop_result) {
 207     // Reallocation may trigger GC. If deoptimization happened on return from
 208     // call which returns oop we need to save it since it is not in oopmap.
 209     oop result = deoptee.saved_oop_result(&map);
 210     assert(oopDesc::is_oop_or_null(result), "must be oop");
 211     return_value = Handle(thread, result);
 212     assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 213     if (TraceDeoptimization) {
 214       ttyLocker ttyl;
 215       tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
 216     }
 217   }
 218   if (objects != NULL) {
 219     if (exec_mode == Deoptimization::Unpack_none) {
 220       assert(thread->thread_state() == _thread_in_vm, "assumption");
 221       JavaThread* THREAD = thread; // For exception macros.
 222       // Clear pending OOM if reallocation fails and return true indicating allocation failure
 223       realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
 224       deoptimized_objects = true;
 225     } else {
 226       JavaThread* current = thread; // For JRT_BLOCK
 227       JRT_BLOCK
 228       realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
 229       JRT_END
 230     }
 231     bool skip_internal = (compiled_method != NULL) && !compiled_method->is_compiled_by_jvmci();
 232     Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal);
 233 #ifndef PRODUCT
 234     if (TraceDeoptimization) {
 235       ttyLocker ttyl;
 236       tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
 237       Deoptimization::print_objects(objects, realloc_failures);
 238     }
 239 #endif
 240   }
 241   if (save_oop_result) {
 242     // Restore result.
 243     deoptee.set_saved_oop_result(&map, return_value());
 244   }
 245   return realloc_failures;
 246 }
 247 
 248 static void restore_eliminated_locks(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures,
 249                                      frame& deoptee, int exec_mode, bool& deoptimized_objects) {
 250   JavaThread* deoptee_thread = chunk->at(0)->thread();
 251   assert(!EscapeBarrier::objs_are_deoptimized(deoptee_thread, deoptee.id()), "must relock just once");
 252   assert(thread == Thread::current(), "should be");
 253   HandleMark hm(thread);
 254 #ifndef PRODUCT
 255   bool first = true;
 256 #endif
 257   for (int i = 0; i < chunk->length(); i++) {
 258     compiledVFrame* cvf = chunk->at(i);
 259     assert (cvf->scope() != NULL,"expect only compiled java frames");
 260     GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 261     if (monitors->is_nonempty()) {
 262       bool relocked = Deoptimization::relock_objects(thread, monitors, deoptee_thread, deoptee,
 263                                                      exec_mode, realloc_failures);
 264       deoptimized_objects = deoptimized_objects || relocked;
 265 #ifndef PRODUCT
 266       if (PrintDeoptimizationDetails) {
 267         ttyLocker ttyl;
 268         for (int j = 0; j < monitors->length(); j++) {
 269           MonitorInfo* mi = monitors->at(j);
 270           if (mi->eliminated()) {
 271             if (first) {
 272               first = false;
 273               tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 274             }
 275             if (exec_mode == Deoptimization::Unpack_none) {
 276               ObjectMonitor* monitor = deoptee_thread->current_waiting_monitor();
 277               if (monitor != NULL && monitor->object() == mi->owner()) {
 278                 tty->print_cr("     object <" INTPTR_FORMAT "> DEFERRED relocking after wait", p2i(mi->owner()));
 279                 continue;
 280               }
 281             }
 282             if (mi->owner_is_scalar_replaced()) {
 283               Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
 284               tty->print_cr("     failed reallocation for klass %s", k->external_name());
 285             } else {
 286               tty->print_cr("     object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
 287             }
 288           }
 289         }
 290       }
 291 #endif // !PRODUCT
 292     }
 293   }
 294 }
 295 
 296 // Deoptimize objects, that is reallocate and relock them, just before they escape through JVMTI.
 297 // The given vframes cover one physical frame.
 298 bool Deoptimization::deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
 299                                                  bool& realloc_failures) {
 300   frame deoptee = chunk->at(0)->fr();
 301   JavaThread* deoptee_thread = chunk->at(0)->thread();
 302   CompiledMethod* cm = deoptee.cb()->as_compiled_method_or_null();
 303   RegisterMap map(chunk->at(0)->register_map());
 304   bool deoptimized_objects = false;
 305 
 306   bool const jvmci_enabled = JVMCI_ONLY(UseJVMCICompiler) NOT_JVMCI(false);
 307 
 308   // Reallocate the non-escaping objects and restore their fields.
 309   if (jvmci_enabled COMPILER2_PRESENT(|| (DoEscapeAnalysis && EliminateAllocations)
 310                                       || EliminateAutoBox || EnableVectorAggressiveReboxing)) {
 311     realloc_failures = rematerialize_objects(thread, Unpack_none, cm, deoptee, map, chunk, deoptimized_objects);
 312   }
 313 
 314   // Revoke biases of objects with eliminated locks in the given frame.
 315   Deoptimization::revoke_for_object_deoptimization(deoptee_thread, deoptee, &map, thread);
 316 
 317   // MonitorInfo structures used in eliminate_locks are not GC safe.
 318   NoSafepointVerifier no_safepoint;
 319 
 320   // Now relock objects if synchronization on them was eliminated.
 321   if (jvmci_enabled COMPILER2_PRESENT(|| ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks))) {
 322     restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
 323   }
 324   return deoptimized_objects;
 325 }
 326 #endif // COMPILER2_OR_JVMCI
 327 
 328 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 329 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
 330   // When we get here we are about to unwind the deoptee frame. In order to
 331   // catch not yet safe to use frames, the following stack watermark barrier
 332   // poll will make such frames safe to use.
 333   StackWatermarkSet::before_unwind(current);
 334 
 335   // Note: there is a safepoint safety issue here. No matter whether we enter
 336   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 337   // the vframeArray is created.
 338   //
 339 
 340   // Allocate our special deoptimization ResourceMark
 341   DeoptResourceMark* dmark = new DeoptResourceMark(current);
 342   assert(current->deopt_mark() == NULL, "Pending deopt!");
 343   current->set_deopt_mark(dmark);
 344 
 345   frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
 346   RegisterMap map(current, true);
 347   RegisterMap dummy_map(current, false);
 348   // Now get the deoptee with a valid map
 349   frame deoptee = stub_frame.sender(&map);
 350   // Set the deoptee nmethod
 351   assert(current->deopt_compiled_method() == NULL, "Pending deopt!");
 352   CompiledMethod* cm = deoptee.cb()->as_compiled_method_or_null();
 353   current->set_deopt_compiled_method(cm);
 354 
 355   if (VerifyStack) {
 356     current->validate_frame_layout();
 357   }
 358 
 359   // Create a growable array of VFrames where each VFrame represents an inlined
 360   // Java frame.  This storage is allocated with the usual system arena.
 361   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 362   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 363   vframe* vf = vframe::new_vframe(&deoptee, &map, current);
 364   while (!vf->is_top()) {
 365     assert(vf->is_compiled_frame(), "Wrong frame type");
 366     chunk->push(compiledVFrame::cast(vf));
 367     vf = vf->sender();
 368   }
 369   assert(vf->is_compiled_frame(), "Wrong frame type");
 370   chunk->push(compiledVFrame::cast(vf));
 371 
 372   bool realloc_failures = false;
 373 
 374 #if COMPILER2_OR_JVMCI
 375   bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
 376 
 377   // Reallocate the non-escaping objects and restore their fields. Then
 378   // relock objects if synchronization on them was eliminated.
 379   if (jvmci_enabled COMPILER2_PRESENT( || (DoEscapeAnalysis && EliminateAllocations)
 380                                        || EliminateAutoBox || EnableVectorAggressiveReboxing )) {
 381     bool unused;
 382     realloc_failures = rematerialize_objects(current, exec_mode, cm, deoptee, map, chunk, unused);
 383   }
 384 #endif // COMPILER2_OR_JVMCI
 385 
 386   // Revoke biases, done with in java state.
 387   // No safepoints allowed after this
 388   revoke_from_deopt_handler(current, deoptee, &map);
 389 
 390   // Ensure that no safepoint is taken after pointers have been stored
 391   // in fields of rematerialized objects.  If a safepoint occurs from here on
 392   // out the java state residing in the vframeArray will be missed.
 393   // Locks may be rebaised in a safepoint.
 394   NoSafepointVerifier no_safepoint;
 395 
 396 #if COMPILER2_OR_JVMCI
 397   if ((jvmci_enabled COMPILER2_PRESENT( || ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) ))
 398       && !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
 399     bool unused;
 400     restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
 401   }
 402 #endif // COMPILER2_OR_JVMCI
 403 
 404   ScopeDesc* trap_scope = chunk->at(0)->scope();
 405   Handle exceptionObject;
 406   if (trap_scope->rethrow_exception()) {
 407     if (PrintDeoptimizationDetails) {
 408       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());
 409     }
 410     GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
 411     guarantee(expressions != NULL && expressions->length() > 0, "must have exception to throw");
 412     ScopeValue* topOfStack = expressions->top();
 413     exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
 414     guarantee(exceptionObject() != NULL, "exception oop can not be null");
 415   }
 416 
 417   vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
 418 #if COMPILER2_OR_JVMCI
 419   if (realloc_failures) {
 420     pop_frames_failed_reallocs(current, array);
 421   }
 422 #endif
 423 
 424   assert(current->vframe_array_head() == NULL, "Pending deopt!");
 425   current->set_vframe_array_head(array);
 426 
 427   // Now that the vframeArray has been created if we have any deferred local writes
 428   // added by jvmti then we can free up that structure as the data is now in the
 429   // vframeArray
 430 
 431   JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
 432 
 433   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 434   CodeBlob* cb = stub_frame.cb();
 435   // Verify we have the right vframeArray
 436   assert(cb->frame_size() >= 0, "Unexpected frame size");
 437   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 438 
 439   // If the deopt call site is a MethodHandle invoke call site we have
 440   // to adjust the unpack_sp.
 441   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 442   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 443     unpack_sp = deoptee.unextended_sp();
 444 
 445 #ifdef ASSERT
 446   assert(cb->is_deoptimization_stub() ||
 447          cb->is_uncommon_trap_stub() ||
 448          strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
 449          strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
 450          "unexpected code blob: %s", cb->name());
 451 #endif
 452 
 453   // This is a guarantee instead of an assert because if vframe doesn't match
 454   // we will unpack the wrong deoptimized frame and wind up in strange places
 455   // where it will be very difficult to figure out what went wrong. Better
 456   // to die an early death here than some very obscure death later when the
 457   // trail is cold.
 458   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 459   // in that it will fail to detect a problem when there is one. This needs
 460   // more work in tiger timeframe.
 461   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 462 
 463   int number_of_frames = array->frames();
 464 
 465   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 466   // virtual activation, which is the reverse of the elements in the vframes array.
 467   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 468   // +1 because we always have an interpreter return address for the final slot.
 469   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 470   int popframe_extra_args = 0;
 471   // Create an interpreter return address for the stub to use as its return
 472   // address so the skeletal frames are perfectly walkable
 473   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 474 
 475   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 476   // activation be put back on the expression stack of the caller for reexecution
 477   if (JvmtiExport::can_pop_frame() && current->popframe_forcing_deopt_reexecution()) {
 478     popframe_extra_args = in_words(current->popframe_preserved_args_size_in_words());
 479   }
 480 
 481   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 482   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 483   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 484   //
 485   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 486   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 487 
 488   // It's possible that the number of parameters at the call site is
 489   // different than number of arguments in the callee when method
 490   // handles are used.  If the caller is interpreted get the real
 491   // value so that the proper amount of space can be added to it's
 492   // frame.
 493   bool caller_was_method_handle = false;
 494   if (deopt_sender.is_interpreted_frame()) {
 495     methodHandle method(current, deopt_sender.interpreter_frame_method());
 496     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 497     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 498       // Method handle invokes may involve fairly arbitrary chains of
 499       // calls so it's impossible to know how much actual space the
 500       // caller has for locals.
 501       caller_was_method_handle = true;
 502     }
 503   }
 504 
 505   //
 506   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 507   // frame_sizes/frame_pcs[1] next oldest frame (int)
 508   // frame_sizes/frame_pcs[n] youngest frame (int)
 509   //
 510   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 511   // owns the space for the return address to it's caller).  Confusing ain't it.
 512   //
 513   // The vframe array can address vframes with indices running from
 514   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 515   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 516   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 517   // so things look a little strange in this loop.
 518   //
 519   int callee_parameters = 0;
 520   int callee_locals = 0;
 521   for (int index = 0; index < array->frames(); index++ ) {
 522     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 523     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 524     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 525     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 526                                                                                                     callee_locals,
 527                                                                                                     index == 0,
 528                                                                                                     popframe_extra_args);
 529     // This pc doesn't have to be perfect just good enough to identify the frame
 530     // as interpreted so the skeleton frame will be walkable
 531     // The correct pc will be set when the skeleton frame is completely filled out
 532     // The final pc we store in the loop is wrong and will be overwritten below
 533     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 534 
 535     callee_parameters = array->element(index)->method()->size_of_parameters();
 536     callee_locals = array->element(index)->method()->max_locals();
 537     popframe_extra_args = 0;
 538   }
 539 
 540   // Compute whether the root vframe returns a float or double value.
 541   BasicType return_type;
 542   {
 543     methodHandle method(current, array->element(0)->method());
 544     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 545     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 546   }
 547 
 548   // Compute information for handling adapters and adjusting the frame size of the caller.
 549   int caller_adjustment = 0;
 550 
 551   // Compute the amount the oldest interpreter frame will have to adjust
 552   // its caller's stack by. If the caller is a compiled frame then
 553   // we pretend that the callee has no parameters so that the
 554   // extension counts for the full amount of locals and not just
 555   // locals-parms. This is because without a c2i adapter the parm
 556   // area as created by the compiled frame will not be usable by
 557   // the interpreter. (Depending on the calling convention there
 558   // may not even be enough space).
 559 
 560   // QQQ I'd rather see this pushed down into last_frame_adjust
 561   // and have it take the sender (aka caller).
 562 
 563   if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
 564     caller_adjustment = last_frame_adjust(0, callee_locals);
 565   } else if (callee_locals > callee_parameters) {
 566     // The caller frame may need extending to accommodate
 567     // non-parameter locals of the first unpacked interpreted frame.
 568     // Compute that adjustment.
 569     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 570   }
 571 
 572   // If the sender is deoptimized the we must retrieve the address of the handler
 573   // since the frame will "magically" show the original pc before the deopt
 574   // and we'd undo the deopt.
 575 
 576   frame_pcs[0] = deopt_sender.raw_pc();
 577 
 578   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 579 
 580 #if INCLUDE_JVMCI
 581   if (exceptionObject() != NULL) {
 582     current->set_exception_oop(exceptionObject());
 583     exec_mode = Unpack_exception;
 584   }
 585 #endif
 586 
 587   if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
 588     assert(current->has_pending_exception(), "should have thrown OOME");
 589     current->set_exception_oop(current->pending_exception());
 590     current->clear_pending_exception();
 591     exec_mode = Unpack_exception;
 592   }
 593 
 594 #if INCLUDE_JVMCI
 595   if (current->frames_to_pop_failed_realloc() > 0) {
 596     current->set_pending_monitorenter(false);
 597   }
 598 #endif
 599 
 600   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 601                                       caller_adjustment * BytesPerWord,
 602                                       caller_was_method_handle ? 0 : callee_parameters,
 603                                       number_of_frames,
 604                                       frame_sizes,
 605                                       frame_pcs,
 606                                       return_type,
 607                                       exec_mode);
 608   // On some platforms, we need a way to pass some platform dependent
 609   // information to the unpacking code so the skeletal frames come out
 610   // correct (initial fp value, unextended sp, ...)
 611   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 612 
 613   if (array->frames() > 1) {
 614     if (VerifyStack && TraceDeoptimization) {
 615       ttyLocker ttyl;
 616       tty->print_cr("Deoptimizing method containing inlining");
 617     }
 618   }
 619 
 620   array->set_unroll_block(info);
 621   return info;
 622 }
 623 
 624 // Called to cleanup deoptimization data structures in normal case
 625 // after unpacking to stack and when stack overflow error occurs
 626 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 627                                         vframeArray *array) {
 628 
 629   // Get array if coming from exception
 630   if (array == NULL) {
 631     array = thread->vframe_array_head();
 632   }
 633   thread->set_vframe_array_head(NULL);
 634 
 635   // Free the previous UnrollBlock
 636   vframeArray* old_array = thread->vframe_array_last();
 637   thread->set_vframe_array_last(array);
 638 
 639   if (old_array != NULL) {
 640     UnrollBlock* old_info = old_array->unroll_block();
 641     old_array->set_unroll_block(NULL);
 642     delete old_info;
 643     delete old_array;
 644   }
 645 
 646   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 647   // inside the vframeArray (StackValueCollections)
 648 
 649   delete thread->deopt_mark();
 650   thread->set_deopt_mark(NULL);
 651   thread->set_deopt_compiled_method(NULL);
 652 
 653 
 654   if (JvmtiExport::can_pop_frame()) {
 655     // Regardless of whether we entered this routine with the pending
 656     // popframe condition bit set, we should always clear it now
 657     thread->clear_popframe_condition();
 658   }
 659 
 660   // unpack_frames() is called at the end of the deoptimization handler
 661   // and (in C2) at the end of the uncommon trap handler. Note this fact
 662   // so that an asynchronous stack walker can work again. This counter is
 663   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 664   // the beginning of uncommon_trap().
 665   thread->dec_in_deopt_handler();
 666 }
 667 
 668 // Moved from cpu directories because none of the cpus has callee save values.
 669 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
 670 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
 671 
 672   // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
 673   // the days we had adapter frames. When we deoptimize a situation where a
 674   // compiled caller calls a compiled caller will have registers it expects
 675   // to survive the call to the callee. If we deoptimize the callee the only
 676   // way we can restore these registers is to have the oldest interpreter
 677   // frame that we create restore these values. That is what this routine
 678   // will accomplish.
 679 
 680   // At the moment we have modified c2 to not have any callee save registers
 681   // so this problem does not exist and this routine is just a place holder.
 682 
 683   assert(f->is_interpreted_frame(), "must be interpreted");
 684 }
 685 
 686 #ifndef PRODUCT
 687 static bool falls_through(Bytecodes::Code bc) {
 688   switch (bc) {
 689     // List may be incomplete.  Here we really only care about bytecodes where compiled code
 690     // can deoptimize.
 691     case Bytecodes::_goto:
 692     case Bytecodes::_goto_w:
 693     case Bytecodes::_athrow:
 694       return false;
 695     default:
 696       return true;
 697   }
 698 }
 699 #endif
 700 
 701 // Return BasicType of value being returned
 702 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 703 
 704   // We are already active in the special DeoptResourceMark any ResourceObj's we
 705   // allocate will be freed at the end of the routine.
 706 
 707   // JRT_LEAF methods don't normally allocate handles and there is a
 708   // NoHandleMark to enforce that. It is actually safe to use Handles
 709   // in a JRT_LEAF method, and sometimes desirable, but to do so we
 710   // must use ResetNoHandleMark to bypass the NoHandleMark, and
 711   // then use a HandleMark to ensure any Handles we do create are
 712   // cleaned up in this scope.
 713   ResetNoHandleMark rnhm;
 714   HandleMark hm(thread);
 715 
 716   frame stub_frame = thread->last_frame();
 717 
 718   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 719   // must point to the vframeArray for the unpack frame.
 720   vframeArray* array = thread->vframe_array_head();
 721 
 722 #ifndef PRODUCT
 723   if (TraceDeoptimization) {
 724     ttyLocker ttyl;
 725     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d",
 726                   p2i(thread), p2i(array), exec_mode);
 727   }
 728 #endif
 729   Events::log_deopt_message(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
 730               p2i(stub_frame.pc()), p2i(stub_frame.sp()), exec_mode);
 731 
 732   UnrollBlock* info = array->unroll_block();
 733 
 734   // We set the last_Java frame. But the stack isn't really parsable here. So we
 735   // clear it to make sure JFR understands not to try and walk stacks from events
 736   // in here.
 737   intptr_t* sp = thread->frame_anchor()->last_Java_sp();
 738   thread->frame_anchor()->set_last_Java_sp(NULL);
 739 
 740   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 741   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 742 
 743   thread->frame_anchor()->set_last_Java_sp(sp);
 744 
 745   BasicType bt = info->return_type();
 746 
 747   // If we have an exception pending, claim that the return type is an oop
 748   // so the deopt_blob does not overwrite the exception_oop.
 749 
 750   if (exec_mode == Unpack_exception)
 751     bt = T_OBJECT;
 752 
 753   // Cleanup thread deopt data
 754   cleanup_deopt_info(thread, array);
 755 
 756 #ifndef PRODUCT
 757   if (VerifyStack) {
 758     ResourceMark res_mark;
 759     // Clear pending exception to not break verification code (restored afterwards)
 760     PreserveExceptionMark pm(thread);
 761 
 762     thread->validate_frame_layout();
 763 
 764     // Verify that the just-unpacked frames match the interpreter's
 765     // notions of expression stack and locals
 766     vframeArray* cur_array = thread->vframe_array_last();
 767     RegisterMap rm(thread, false);
 768     rm.set_include_argument_oops(false);
 769     bool is_top_frame = true;
 770     int callee_size_of_parameters = 0;
 771     int callee_max_locals = 0;
 772     for (int i = 0; i < cur_array->frames(); i++) {
 773       vframeArrayElement* el = cur_array->element(i);
 774       frame* iframe = el->iframe();
 775       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 776 
 777       // Get the oop map for this bci
 778       InterpreterOopMap mask;
 779       int cur_invoke_parameter_size = 0;
 780       bool try_next_mask = false;
 781       int next_mask_expression_stack_size = -1;
 782       int top_frame_expression_stack_adjustment = 0;
 783       methodHandle mh(thread, iframe->interpreter_frame_method());
 784       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 785       BytecodeStream str(mh, iframe->interpreter_frame_bci());
 786       int max_bci = mh->code_size();
 787       // Get to the next bytecode if possible
 788       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 789       // Check to see if we can grab the number of outgoing arguments
 790       // at an uncommon trap for an invoke (where the compiler
 791       // generates debug info before the invoke has executed)
 792       Bytecodes::Code cur_code = str.next();
 793       Bytecodes::Code next_code = Bytecodes::_shouldnotreachhere;
 794       if (Bytecodes::is_invoke(cur_code)) {
 795         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 796         cur_invoke_parameter_size = invoke.size_of_parameters();
 797         if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
 798           callee_size_of_parameters++;
 799         }
 800       }
 801       if (str.bci() < max_bci) {
 802         next_code = str.next();
 803         if (next_code >= 0) {
 804           // The interpreter oop map generator reports results before
 805           // the current bytecode has executed except in the case of
 806           // calls. It seems to be hard to tell whether the compiler
 807           // has emitted debug information matching the "state before"
 808           // a given bytecode or the state after, so we try both
 809           if (!Bytecodes::is_invoke(cur_code) && falls_through(cur_code)) {
 810             // Get expression stack size for the next bytecode
 811             InterpreterOopMap next_mask;
 812             OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 813             next_mask_expression_stack_size = next_mask.expression_stack_size();
 814             if (Bytecodes::is_invoke(next_code)) {
 815               Bytecode_invoke invoke(mh, str.bci());
 816               next_mask_expression_stack_size += invoke.size_of_parameters();
 817             }
 818             // Need to subtract off the size of the result type of
 819             // the bytecode because this is not described in the
 820             // debug info but returned to the interpreter in the TOS
 821             // caching register
 822             BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 823             if (bytecode_result_type != T_ILLEGAL) {
 824               top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 825             }
 826             assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
 827             try_next_mask = true;
 828           }
 829         }
 830       }
 831 
 832       // Verify stack depth and oops in frame
 833       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 834       if (!(
 835             /* SPARC */
 836             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 837             /* x86 */
 838             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 839             (try_next_mask &&
 840              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 841                                                                     top_frame_expression_stack_adjustment))) ||
 842             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 843             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
 844              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 845             )) {
 846         {
 847           ttyLocker ttyl;
 848 
 849           // Print out some information that will help us debug the problem
 850           tty->print_cr("Wrong number of expression stack elements during deoptimization");
 851           tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 852           tty->print_cr("  Current code %s", Bytecodes::name(cur_code));
 853           if (try_next_mask) {
 854             tty->print_cr("  Next code %s", Bytecodes::name(next_code));
 855           }
 856           tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 857                         iframe->interpreter_frame_expression_stack_size());
 858           tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 859           tty->print_cr("  try_next_mask = %d", try_next_mask);
 860           tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 861           tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 862           tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 863           tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 864           tty->print_cr("  exec_mode = %d", exec_mode);
 865           tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 866           tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
 867           tty->print_cr("  Interpreted frames:");
 868           for (int k = 0; k < cur_array->frames(); k++) {
 869             vframeArrayElement* el = cur_array->element(k);
 870             tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 871           }
 872           cur_array->print_on_2(tty);
 873         } // release tty lock before calling guarantee
 874         guarantee(false, "wrong number of expression stack elements during deopt");
 875       }
 876       VerifyOopClosure verify;
 877       iframe->oops_interpreted_do(&verify, &rm, false);
 878       callee_size_of_parameters = mh->size_of_parameters();
 879       callee_max_locals = mh->max_locals();
 880       is_top_frame = false;
 881     }
 882   }
 883 #endif /* !PRODUCT */
 884 
 885   return bt;
 886 JRT_END
 887 
 888 class DeoptimizeMarkedClosure : public HandshakeClosure {
 889  public:
 890   DeoptimizeMarkedClosure() : HandshakeClosure("Deoptimize") {}
 891   void do_thread(Thread* thread) {
 892     JavaThread* jt = thread->as_Java_thread();
 893     jt->deoptimize_marked_methods();
 894   }
 895 };
 896 
 897 void Deoptimization::deoptimize_all_marked(nmethod* nmethod_only) {
 898   ResourceMark rm;
 899   DeoptimizationMarker dm;
 900 
 901   // Make the dependent methods not entrant
 902   if (nmethod_only != NULL) {
 903     nmethod_only->mark_for_deoptimization();
 904     nmethod_only->make_not_entrant();
 905   } else {
 906     MutexLocker mu(SafepointSynchronize::is_at_safepoint() ? NULL : CodeCache_lock, Mutex::_no_safepoint_check_flag);
 907     CodeCache::make_marked_nmethods_not_entrant();
 908   }
 909 
 910   DeoptimizeMarkedClosure deopt;
 911   if (SafepointSynchronize::is_at_safepoint()) {
 912     Threads::java_threads_do(&deopt);
 913   } else {
 914     Handshake::execute(&deopt);
 915   }
 916 }
 917 
 918 Deoptimization::DeoptAction Deoptimization::_unloaded_action
 919   = Deoptimization::Action_reinterpret;
 920 
 921 #if COMPILER2_OR_JVMCI
 922 template<typename CacheType>
 923 class BoxCacheBase : public CHeapObj<mtCompiler> {
 924 protected:
 925   static InstanceKlass* find_cache_klass(Symbol* klass_name) {
 926     ResourceMark rm;
 927     char* klass_name_str = klass_name->as_C_string();
 928     InstanceKlass* ik = SystemDictionary::find_instance_klass(klass_name, Handle(), Handle());
 929     guarantee(ik != NULL, "%s must be loaded", klass_name_str);
 930     guarantee(ik->is_initialized(), "%s must be initialized", klass_name_str);
 931     CacheType::compute_offsets(ik);
 932     return ik;
 933   }
 934 };
 935 
 936 template<typename PrimitiveType, typename CacheType, typename BoxType> class BoxCache  : public BoxCacheBase<CacheType> {
 937   PrimitiveType _low;
 938   PrimitiveType _high;
 939   jobject _cache;
 940 protected:
 941   static BoxCache<PrimitiveType, CacheType, BoxType> *_singleton;
 942   BoxCache(Thread* thread) {
 943     InstanceKlass* ik = BoxCacheBase<CacheType>::find_cache_klass(CacheType::symbol());
 944     objArrayOop cache = CacheType::cache(ik);
 945     assert(cache->length() > 0, "Empty cache");
 946     _low = BoxType::value(cache->obj_at(0));
 947     _high = _low + cache->length() - 1;
 948     _cache = JNIHandles::make_global(Handle(thread, cache));
 949   }
 950   ~BoxCache() {
 951     JNIHandles::destroy_global(_cache);
 952   }
 953 public:
 954   static BoxCache<PrimitiveType, CacheType, BoxType>* singleton(Thread* thread) {
 955     if (_singleton == NULL) {
 956       BoxCache<PrimitiveType, CacheType, BoxType>* s = new BoxCache<PrimitiveType, CacheType, BoxType>(thread);
 957       if (!Atomic::replace_if_null(&_singleton, s)) {
 958         delete s;
 959       }
 960     }
 961     return _singleton;
 962   }
 963   oop lookup(PrimitiveType value) {
 964     if (_low <= value && value <= _high) {
 965       int offset = value - _low;
 966       return objArrayOop(JNIHandles::resolve_non_null(_cache))->obj_at(offset);
 967     }
 968     return NULL;
 969   }
 970   oop lookup_raw(intptr_t raw_value) {
 971     // Have to cast to avoid little/big-endian problems.
 972     if (sizeof(PrimitiveType) > sizeof(jint)) {
 973       jlong value = (jlong)raw_value;
 974       return lookup(value);
 975     }
 976     PrimitiveType value = (PrimitiveType)*((jint*)&raw_value);
 977     return lookup(value);
 978   }
 979 };
 980 
 981 typedef BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer> IntegerBoxCache;
 982 typedef BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long> LongBoxCache;
 983 typedef BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character> CharacterBoxCache;
 984 typedef BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short> ShortBoxCache;
 985 typedef BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte> ByteBoxCache;
 986 
 987 template<> BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>* BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>::_singleton = NULL;
 988 template<> BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>* BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>::_singleton = NULL;
 989 template<> BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>* BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>::_singleton = NULL;
 990 template<> BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>* BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>::_singleton = NULL;
 991 template<> BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>* BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>::_singleton = NULL;
 992 
 993 class BooleanBoxCache : public BoxCacheBase<java_lang_Boolean> {
 994   jobject _true_cache;
 995   jobject _false_cache;
 996 protected:
 997   static BooleanBoxCache *_singleton;
 998   BooleanBoxCache(Thread *thread) {
 999     InstanceKlass* ik = find_cache_klass(java_lang_Boolean::symbol());
1000     _true_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_TRUE(ik)));
1001     _false_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_FALSE(ik)));
1002   }
1003   ~BooleanBoxCache() {
1004     JNIHandles::destroy_global(_true_cache);
1005     JNIHandles::destroy_global(_false_cache);
1006   }
1007 public:
1008   static BooleanBoxCache* singleton(Thread* thread) {
1009     if (_singleton == NULL) {
1010       BooleanBoxCache* s = new BooleanBoxCache(thread);
1011       if (!Atomic::replace_if_null(&_singleton, s)) {
1012         delete s;
1013       }
1014     }
1015     return _singleton;
1016   }
1017   oop lookup_raw(intptr_t raw_value) {
1018     // Have to cast to avoid little/big-endian problems.
1019     jboolean value = (jboolean)*((jint*)&raw_value);
1020     return lookup(value);
1021   }
1022   oop lookup(jboolean value) {
1023     if (value != 0) {
1024       return JNIHandles::resolve_non_null(_true_cache);
1025     }
1026     return JNIHandles::resolve_non_null(_false_cache);
1027   }
1028 };
1029 
1030 BooleanBoxCache* BooleanBoxCache::_singleton = NULL;
1031 
1032 oop Deoptimization::get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, TRAPS) {
1033    Klass* k = java_lang_Class::as_Klass(bv->klass()->as_ConstantOopReadValue()->value()());
1034    BasicType box_type = vmClasses::box_klass_type(k);
1035    if (box_type != T_OBJECT) {
1036      StackValue* value = StackValue::create_stack_value(fr, reg_map, bv->field_at(box_type == T_LONG ? 1 : 0));
1037      switch(box_type) {
1038        case T_INT:     return IntegerBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1039        case T_CHAR:    return CharacterBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1040        case T_SHORT:   return ShortBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1041        case T_BYTE:    return ByteBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1042        case T_BOOLEAN: return BooleanBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1043        case T_LONG:    return LongBoxCache::singleton(THREAD)->lookup_raw(value->get_int());
1044        default:;
1045      }
1046    }
1047    return NULL;
1048 }
1049 
1050 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1051   Handle pending_exception(THREAD, thread->pending_exception());
1052   const char* exception_file = thread->exception_file();
1053   int exception_line = thread->exception_line();
1054   thread->clear_pending_exception();
1055 
1056   bool failures = false;
1057 
1058   for (int i = 0; i < objects->length(); i++) {
1059     assert(objects->at(i)->is_object(), "invalid debug information");
1060     ObjectValue* sv = (ObjectValue*) objects->at(i);
1061 
1062     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1063     oop obj = NULL;
1064 
1065     if (k->is_instance_klass()) {
1066       if (sv->is_auto_box()) {
1067         AutoBoxObjectValue* abv = (AutoBoxObjectValue*) sv;
1068         obj = get_cached_box(abv, fr, reg_map, THREAD);
1069         if (obj != NULL) {
1070           // Set the flag to indicate the box came from a cache, so that we can skip the field reassignment for it.
1071           abv->set_cached(true);
1072         }
1073       }
1074 
1075       InstanceKlass* ik = InstanceKlass::cast(k);
1076       if (obj == NULL) {
1077 #ifdef COMPILER2
1078         if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1079           obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1080         } else {
1081           obj = ik->allocate_instance(THREAD);
1082         }
1083 #else
1084         obj = ik->allocate_instance(THREAD);
1085 #endif // COMPILER2
1086       }
1087     } else if (k->is_typeArray_klass()) {
1088       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1089       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1090       int len = sv->field_size() / type2size[ak->element_type()];
1091       obj = ak->allocate(len, THREAD);
1092     } else if (k->is_objArray_klass()) {
1093       ObjArrayKlass* ak = ObjArrayKlass::cast(k);
1094       obj = ak->allocate(sv->field_size(), THREAD);
1095     }
1096 
1097     if (obj == NULL) {
1098       failures = true;
1099     }
1100 
1101     assert(sv->value().is_null(), "redundant reallocation");
1102     assert(obj != NULL || HAS_PENDING_EXCEPTION, "allocation should succeed or we should get an exception");
1103     CLEAR_PENDING_EXCEPTION;
1104     sv->set_value(obj);
1105   }
1106 
1107   if (failures) {
1108     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1109   } else if (pending_exception.not_null()) {
1110     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1111   }
1112 
1113   return failures;
1114 }
1115 
1116 #if INCLUDE_JVMCI
1117 /**
1118  * For primitive types whose kind gets "erased" at runtime (shorts become stack ints),
1119  * we need to somehow be able to recover the actual kind to be able to write the correct
1120  * amount of bytes.
1121  * For that purpose, this method assumes that, for an entry spanning n bytes at index i,
1122  * the entries at index n + 1 to n + i are 'markers'.
1123  * For example, if we were writing a short at index 4 of a byte array of size 8, the
1124  * expected form of the array would be:
1125  *
1126  * {b0, b1, b2, b3, INT, marker, b6, b7}
1127  *
1128  * Thus, in order to get back the size of the entry, we simply need to count the number
1129  * of marked entries
1130  *
1131  * @param virtualArray the virtualized byte array
1132  * @param i index of the virtual entry we are recovering
1133  * @return The number of bytes the entry spans
1134  */
1135 static int count_number_of_bytes_for_entry(ObjectValue *virtualArray, int i) {
1136   int index = i;
1137   while (++index < virtualArray->field_size() &&
1138            virtualArray->field_at(index)->is_marker()) {}
1139   return index - i;
1140 }
1141 
1142 /**
1143  * If there was a guarantee for byte array to always start aligned to a long, we could
1144  * do a simple check on the parity of the index. Unfortunately, that is not always the
1145  * case. Thus, we check alignment of the actual address we are writing to.
1146  * In the unlikely case index 0 is 5-aligned for example, it would then be possible to
1147  * write a long to index 3.
1148  */
1149 static jbyte* check_alignment_get_addr(typeArrayOop obj, int index, int expected_alignment) {
1150     jbyte* res = obj->byte_at_addr(index);
1151     assert((((intptr_t) res) % expected_alignment) == 0, "Non-aligned write");
1152     return res;
1153 }
1154 
1155 static void byte_array_put(typeArrayOop obj, intptr_t val, int index, int byte_count) {
1156   switch (byte_count) {
1157     case 1:
1158       obj->byte_at_put(index, (jbyte) *((jint *) &val));
1159       break;
1160     case 2:
1161       *((jshort *) check_alignment_get_addr(obj, index, 2)) = (jshort) *((jint *) &val);
1162       break;
1163     case 4:
1164       *((jint *) check_alignment_get_addr(obj, index, 4)) = (jint) *((jint *) &val);
1165       break;
1166     case 8:
1167       *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) *((jlong *) &val);
1168       break;
1169     default:
1170       ShouldNotReachHere();
1171   }
1172 }
1173 #endif // INCLUDE_JVMCI
1174 
1175 
1176 // restore elements of an eliminated type array
1177 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1178   int index = 0;
1179   intptr_t val;
1180 
1181   for (int i = 0; i < sv->field_size(); i++) {
1182     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1183     switch(type) {
1184     case T_LONG: case T_DOUBLE: {
1185       assert(value->type() == T_INT, "Agreement.");
1186       StackValue* low =
1187         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1188 #ifdef _LP64
1189       jlong res = (jlong)low->get_int();
1190 #else
1191       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
1192 #endif
1193       obj->long_at_put(index, res);
1194       break;
1195     }
1196 
1197     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
1198     case T_INT: case T_FLOAT: { // 4 bytes.
1199       assert(value->type() == T_INT, "Agreement.");
1200       bool big_value = false;
1201       if (i + 1 < sv->field_size() && type == T_INT) {
1202         if (sv->field_at(i)->is_location()) {
1203           Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
1204           if (type == Location::dbl || type == Location::lng) {
1205             big_value = true;
1206           }
1207         } else if (sv->field_at(i)->is_constant_int()) {
1208           ScopeValue* next_scope_field = sv->field_at(i + 1);
1209           if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1210             big_value = true;
1211           }
1212         }
1213       }
1214 
1215       if (big_value) {
1216         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1217   #ifdef _LP64
1218         jlong res = (jlong)low->get_int();
1219   #else
1220         jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
1221   #endif
1222         obj->int_at_put(index, (jint)*((jint*)&res));
1223         obj->int_at_put(++index, (jint)*(((jint*)&res) + 1));
1224       } else {
1225         val = value->get_int();
1226         obj->int_at_put(index, (jint)*((jint*)&val));
1227       }
1228       break;
1229     }
1230 
1231     case T_SHORT:
1232       assert(value->type() == T_INT, "Agreement.");
1233       val = value->get_int();
1234       obj->short_at_put(index, (jshort)*((jint*)&val));
1235       break;
1236 
1237     case T_CHAR:
1238       assert(value->type() == T_INT, "Agreement.");
1239       val = value->get_int();
1240       obj->char_at_put(index, (jchar)*((jint*)&val));
1241       break;
1242 
1243     case T_BYTE: {
1244       assert(value->type() == T_INT, "Agreement.");
1245       // The value we get is erased as a regular int. We will need to find its actual byte count 'by hand'.
1246       val = value->get_int();
1247 #if INCLUDE_JVMCI
1248       int byte_count = count_number_of_bytes_for_entry(sv, i);
1249       byte_array_put(obj, val, index, byte_count);
1250       // According to byte_count contract, the values from i + 1 to i + byte_count are illegal values. Skip.
1251       i += byte_count - 1; // Balance the loop counter.
1252       index += byte_count;
1253       // index has been updated so continue at top of loop
1254       continue;
1255 #else
1256       obj->byte_at_put(index, (jbyte)*((jint*)&val));
1257       break;
1258 #endif // INCLUDE_JVMCI
1259     }
1260 
1261     case T_BOOLEAN: {
1262       assert(value->type() == T_INT, "Agreement.");
1263       val = value->get_int();
1264       obj->bool_at_put(index, (jboolean)*((jint*)&val));
1265       break;
1266     }
1267 
1268       default:
1269         ShouldNotReachHere();
1270     }
1271     index++;
1272   }
1273 }
1274 
1275 // restore fields of an eliminated object array
1276 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1277   for (int i = 0; i < sv->field_size(); i++) {
1278     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1279     assert(value->type() == T_OBJECT, "object element expected");
1280     obj->obj_at_put(i, value->get_obj()());
1281   }
1282 }
1283 
1284 class ReassignedField {
1285 public:
1286   int _offset;
1287   BasicType _type;
1288 public:
1289   ReassignedField() {
1290     _offset = 0;
1291     _type = T_ILLEGAL;
1292   }
1293 };
1294 
1295 int compare(ReassignedField* left, ReassignedField* right) {
1296   return left->_offset - right->_offset;
1297 }
1298 
1299 // Restore fields of an eliminated instance object using the same field order
1300 // returned by HotSpotResolvedObjectTypeImpl.getInstanceFields(true)
1301 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool skip_internal) {
1302   GrowableArray<ReassignedField>* fields = new GrowableArray<ReassignedField>();
1303   InstanceKlass* ik = klass;
1304   while (ik != NULL) {
1305     for (AllFieldStream fs(ik); !fs.done(); fs.next()) {
1306       if (!fs.access_flags().is_static() && (!skip_internal || !fs.access_flags().is_internal())) {
1307         ReassignedField field;
1308         field._offset = fs.offset();
1309         field._type = Signature::basic_type(fs.signature());
1310         fields->append(field);
1311       }
1312     }
1313     ik = ik->superklass();
1314   }
1315   fields->sort(compare);
1316   for (int i = 0; i < fields->length(); i++) {
1317     intptr_t val;
1318     ScopeValue* scope_field = sv->field_at(svIndex);
1319     StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1320     int offset = fields->at(i)._offset;
1321     BasicType type = fields->at(i)._type;
1322     switch (type) {
1323       case T_OBJECT: case T_ARRAY:
1324         assert(value->type() == T_OBJECT, "Agreement.");
1325         obj->obj_field_put(offset, value->get_obj()());
1326         break;
1327 
1328       // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
1329       case T_INT: case T_FLOAT: { // 4 bytes.
1330         assert(value->type() == T_INT, "Agreement.");
1331         bool big_value = false;
1332         if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1333           if (scope_field->is_location()) {
1334             Location::Type type = ((LocationValue*) scope_field)->location().type();
1335             if (type == Location::dbl || type == Location::lng) {
1336               big_value = true;
1337             }
1338           }
1339           if (scope_field->is_constant_int()) {
1340             ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1341             if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1342               big_value = true;
1343             }
1344           }
1345         }
1346 
1347         if (big_value) {
1348           i++;
1349           assert(i < fields->length(), "second T_INT field needed");
1350           assert(fields->at(i)._type == T_INT, "T_INT field needed");
1351         } else {
1352           val = value->get_int();
1353           obj->int_field_put(offset, (jint)*((jint*)&val));
1354           break;
1355         }
1356       }
1357         /* no break */
1358 
1359       case T_LONG: case T_DOUBLE: {
1360         assert(value->type() == T_INT, "Agreement.");
1361         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1362 #ifdef _LP64
1363         jlong res = (jlong)low->get_int();
1364 #else
1365         jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
1366 #endif
1367         obj->long_field_put(offset, res);
1368         break;
1369       }
1370 
1371       case T_SHORT:
1372         assert(value->type() == T_INT, "Agreement.");
1373         val = value->get_int();
1374         obj->short_field_put(offset, (jshort)*((jint*)&val));
1375         break;
1376 
1377       case T_CHAR:
1378         assert(value->type() == T_INT, "Agreement.");
1379         val = value->get_int();
1380         obj->char_field_put(offset, (jchar)*((jint*)&val));
1381         break;
1382 
1383       case T_BYTE:
1384         assert(value->type() == T_INT, "Agreement.");
1385         val = value->get_int();
1386         obj->byte_field_put(offset, (jbyte)*((jint*)&val));
1387         break;
1388 
1389       case T_BOOLEAN:
1390         assert(value->type() == T_INT, "Agreement.");
1391         val = value->get_int();
1392         obj->bool_field_put(offset, (jboolean)*((jint*)&val));
1393         break;
1394 
1395       default:
1396         ShouldNotReachHere();
1397     }
1398     svIndex++;
1399   }
1400   return svIndex;
1401 }
1402 
1403 // restore fields of all eliminated objects and arrays
1404 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal) {
1405   for (int i = 0; i < objects->length(); i++) {
1406     ObjectValue* sv = (ObjectValue*) objects->at(i);
1407     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1408     Handle obj = sv->value();
1409     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1410     if (PrintDeoptimizationDetails) {
1411       tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1412     }
1413     if (obj.is_null()) {
1414       continue;
1415     }
1416 
1417     // Don't reassign fields of boxes that came from a cache. Caches may be in CDS.
1418     if (sv->is_auto_box() && ((AutoBoxObjectValue*) sv)->is_cached()) {
1419       continue;
1420     }
1421 #ifdef COMPILER2
1422     if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1423       assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1424       ScopeValue* payload = sv->field_at(0);
1425       if (payload->is_location() &&
1426           payload->as_LocationValue()->location().type() == Location::vector) {
1427         if (PrintDeoptimizationDetails) {
1428           tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1429           if (Verbose) {
1430             Handle obj = sv->value();
1431             k->oop_print_on(obj(), tty);
1432           }
1433         }
1434         continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1435       }
1436       // Else fall-through to do assignment for scalar-replaced boxed vector representation
1437       // which could be restored after vector object allocation.
1438     }
1439 #endif
1440     if (k->is_instance_klass()) {
1441       InstanceKlass* ik = InstanceKlass::cast(k);
1442       reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), skip_internal);
1443     } else if (k->is_typeArray_klass()) {
1444       TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1445       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1446     } else if (k->is_objArray_klass()) {
1447       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1448     }
1449   }
1450 }
1451 
1452 
1453 // relock objects for which synchronization was eliminated
1454 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1455                                     JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1456   bool relocked_objects = false;
1457   for (int i = 0; i < monitors->length(); i++) {
1458     MonitorInfo* mon_info = monitors->at(i);
1459     if (mon_info->eliminated()) {
1460       assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1461       relocked_objects = true;
1462       if (!mon_info->owner_is_scalar_replaced()) {
1463         Handle obj(thread, mon_info->owner());
1464         markWord mark = obj->mark();
1465         if (UseBiasedLocking && mark.has_bias_pattern()) {
1466           // New allocated objects may have the mark set to anonymously biased.
1467           // Also the deoptimized method may called methods with synchronization
1468           // where the thread-local object is bias locked to the current thread.
1469           assert(mark.is_biased_anonymously() ||
1470                  mark.biased_locker() == deoptee_thread, "should be locked to current thread");
1471           // Reset mark word to unbiased prototype.
1472           markWord unbiased_prototype = markWord::prototype().set_age(mark.age());
1473           obj->set_mark(unbiased_prototype);
1474         } else if (exec_mode == Unpack_none) {
1475           if (mark.has_locker() && fr.sp() > (intptr_t*)mark.locker()) {
1476             // With exec_mode == Unpack_none obj may be thread local and locked in
1477             // a callee frame. In this case the bias was revoked before in revoke_for_object_deoptimization().
1478             // Make the lock in the callee a recursive lock and restore the displaced header.
1479             markWord dmw = mark.displaced_mark_helper();
1480             mark.locker()->set_displaced_header(markWord::encode((BasicLock*) NULL));
1481             obj->set_mark(dmw);
1482           }
1483           if (mark.has_monitor()) {
1484             // defer relocking if the deoptee thread is currently waiting for obj
1485             ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1486             if (waiting_monitor != NULL && waiting_monitor->object() == obj()) {
1487               assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1488               mon_info->lock()->set_displaced_header(markWord::unused_mark());
1489               JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1490               continue;
1491             }
1492           }
1493         }
1494         BasicLock* lock = mon_info->lock();
1495         ObjectSynchronizer::enter(obj, lock, deoptee_thread);
1496         assert(mon_info->owner()->is_locked(), "object must be locked now");
1497       }
1498     }
1499   }
1500   return relocked_objects;
1501 }
1502 
1503 
1504 #ifndef PRODUCT
1505 // print information about reallocated objects
1506 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
1507   fieldDescriptor fd;
1508 
1509   for (int i = 0; i < objects->length(); i++) {
1510     ObjectValue* sv = (ObjectValue*) objects->at(i);
1511     Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1512     Handle obj = sv->value();
1513 
1514     tty->print("     object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
1515     k->print_value();
1516     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1517     if (obj.is_null()) {
1518       tty->print(" allocation failed");
1519     } else {
1520       tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
1521     }
1522     tty->cr();
1523 
1524     if (Verbose && !obj.is_null()) {
1525       k->oop_print_on(obj(), tty);
1526     }
1527   }
1528 }
1529 #endif
1530 #endif // COMPILER2_OR_JVMCI
1531 
1532 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1533   Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1534 
1535 #ifndef PRODUCT
1536   if (PrintDeoptimizationDetails) {
1537     ttyLocker ttyl;
1538     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", p2i(thread));
1539     fr.print_on(tty);
1540     tty->print_cr("     Virtual frames (innermost first):");
1541     for (int index = 0; index < chunk->length(); index++) {
1542       compiledVFrame* vf = chunk->at(index);
1543       tty->print("       %2d - ", index);
1544       vf->print_value();
1545       int bci = chunk->at(index)->raw_bci();
1546       const char* code_name;
1547       if (bci == SynchronizationEntryBCI) {
1548         code_name = "sync entry";
1549       } else {
1550         Bytecodes::Code code = vf->method()->code_at(bci);
1551         code_name = Bytecodes::name(code);
1552       }
1553       tty->print(" - %s", code_name);
1554       tty->print_cr(" @ bci %d ", bci);
1555       if (Verbose) {
1556         vf->print();
1557         tty->cr();
1558       }
1559     }
1560   }
1561 #endif
1562 
1563   // Register map for next frame (used for stack crawl).  We capture
1564   // the state of the deopt'ing frame's caller.  Thus if we need to
1565   // stuff a C2I adapter we can properly fill in the callee-save
1566   // register locations.
1567   frame caller = fr.sender(reg_map);
1568   int frame_size = caller.sp() - fr.sp();
1569 
1570   frame sender = caller;
1571 
1572   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1573   // the vframeArray containing the unpacking information is allocated in the C heap.
1574   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1575   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1576 
1577   // Compare the vframeArray to the collected vframes
1578   assert(array->structural_compare(thread, chunk), "just checking");
1579 
1580 #ifndef PRODUCT
1581   if (PrintDeoptimizationDetails) {
1582     ttyLocker ttyl;
1583     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, p2i(array));
1584   }
1585 #endif // PRODUCT
1586 
1587   return array;
1588 }
1589 
1590 #if COMPILER2_OR_JVMCI
1591 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1592   // Reallocation of some scalar replaced objects failed. Record
1593   // that we need to pop all the interpreter frames for the
1594   // deoptimized compiled frame.
1595   assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1596   thread->set_frames_to_pop_failed_realloc(array->frames());
1597   // Unlock all monitors here otherwise the interpreter will see a
1598   // mix of locked and unlocked monitors (because of failed
1599   // reallocations of synchronized objects) and be confused.
1600   for (int i = 0; i < array->frames(); i++) {
1601     MonitorChunk* monitors = array->element(i)->monitors();
1602     if (monitors != NULL) {
1603       for (int j = 0; j < monitors->number_of_monitors(); j++) {
1604         BasicObjectLock* src = monitors->at(j);
1605         if (src->obj() != NULL) {
1606           ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1607         }
1608       }
1609       array->element(i)->free_monitors(thread);
1610 #ifdef ASSERT
1611       array->element(i)->set_removed_monitors();
1612 #endif
1613     }
1614   }
1615 }
1616 #endif
1617 
1618 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke,
1619                              bool only_eliminated) {
1620   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1621   Thread* thread = Thread::current();
1622   for (int i = 0; i < monitors->length(); i++) {
1623     MonitorInfo* mon_info = monitors->at(i);
1624     if (mon_info->eliminated() == only_eliminated &&
1625         !mon_info->owner_is_scalar_replaced() &&
1626         mon_info->owner() != NULL) {
1627       objects_to_revoke->append(Handle(thread, mon_info->owner()));
1628     }
1629   }
1630 }
1631 
1632 static void get_monitors_from_stack(GrowableArray<Handle>* objects_to_revoke, JavaThread* thread,
1633                                     frame fr, RegisterMap* map, bool only_eliminated) {
1634   // Unfortunately we don't have a RegisterMap available in most of
1635   // the places we want to call this routine so we need to walk the
1636   // stack again to update the register map.
1637   if (map == NULL || !map->update_map()) {
1638     StackFrameStream sfs(thread, true /* update */, true /* process_frames */);
1639     bool found = false;
1640     while (!found && !sfs.is_done()) {
1641       frame* cur = sfs.current();
1642       sfs.next();
1643       found = cur->id() == fr.id();
1644     }
1645     assert(found, "frame to be deoptimized not found on target thread's stack");
1646     map = sfs.register_map();
1647   }
1648 
1649   vframe* vf = vframe::new_vframe(&fr, map, thread);
1650   compiledVFrame* cvf = compiledVFrame::cast(vf);
1651   // Revoke monitors' biases in all scopes
1652   while (!cvf->is_top()) {
1653     collect_monitors(cvf, objects_to_revoke, only_eliminated);
1654     cvf = compiledVFrame::cast(cvf->sender());
1655   }
1656   collect_monitors(cvf, objects_to_revoke, only_eliminated);
1657 }
1658 
1659 void Deoptimization::revoke_from_deopt_handler(JavaThread* thread, frame fr, RegisterMap* map) {
1660   if (!UseBiasedLocking) {
1661     return;
1662   }
1663   assert(thread == Thread::current(), "should be");
1664   ResourceMark rm(thread);
1665   HandleMark hm(thread);
1666   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1667   get_monitors_from_stack(objects_to_revoke, thread, fr, map, false);
1668 
1669   int len = objects_to_revoke->length();
1670   for (int i = 0; i < len; i++) {
1671     oop obj = (objects_to_revoke->at(i))();
1672     BiasedLocking::revoke_own_lock(thread, objects_to_revoke->at(i));
1673     assert(!obj->mark().has_bias_pattern(), "biases should be revoked by now");
1674   }
1675 }
1676 
1677 // Revoke the bias of objects with eliminated locking to prepare subsequent relocking.
1678 void Deoptimization::revoke_for_object_deoptimization(JavaThread* deoptee_thread, frame fr,
1679                                                       RegisterMap* map, JavaThread* thread) {
1680   if (!UseBiasedLocking) {
1681     return;
1682   }
1683   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1684   assert(KeepStackGCProcessedMark::stack_is_kept_gc_processed(deoptee_thread), "must be");
1685   // Collect monitors but only those with eliminated locking.
1686   get_monitors_from_stack(objects_to_revoke, deoptee_thread, fr, map, true);
1687 
1688   int len = objects_to_revoke->length();
1689   for (int i = 0; i < len; i++) {
1690     oop obj = (objects_to_revoke->at(i))();
1691     markWord mark = obj->mark();
1692     if (!mark.has_bias_pattern() ||
1693         mark.is_biased_anonymously() || // eliminated locking does not bias an object if it wasn't before
1694         !obj->klass()->prototype_header().has_bias_pattern() || // bulk revoke ignores eliminated monitors
1695         (obj->klass()->prototype_header().bias_epoch() != mark.bias_epoch())) { // bulk rebias ignores eliminated monitors
1696       // We reach here regularly if there's just eliminated locking on obj.
1697       // We must not call BiasedLocking::revoke_own_lock() in this case, as we
1698       // would hit assertions because it is a prerequisite that there has to be
1699       // non-eliminated locking on obj by deoptee_thread.
1700       // Luckily we don't have to revoke here because obj has to be a
1701       // non-escaping obj and can be relocked without revoking the bias. See
1702       // Deoptimization::relock_objects().
1703       continue;
1704     }
1705     BiasedLocking::revoke(thread, objects_to_revoke->at(i));
1706     assert(!objects_to_revoke->at(i)->mark().has_bias_pattern(), "biases should be revoked by now");
1707   }
1708 }
1709 
1710 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1711   assert(fr.can_be_deoptimized(), "checking frame type");
1712 
1713   gather_statistics(reason, Action_none, Bytecodes::_illegal);
1714 
1715   if (LogCompilation && xtty != NULL) {
1716     CompiledMethod* cm = fr.cb()->as_compiled_method_or_null();
1717     assert(cm != NULL, "only compiled methods can deopt");
1718 
1719     ttyLocker ttyl;
1720     xtty->begin_head("deoptimized thread='" UINTX_FORMAT "' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1721     cm->log_identity(xtty);
1722     xtty->end_head();
1723     for (ScopeDesc* sd = cm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1724       xtty->begin_elem("jvms bci='%d'", sd->bci());
1725       xtty->method(sd->method());
1726       xtty->end_elem();
1727       if (sd->is_top())  break;
1728     }
1729     xtty->tail("deoptimized");
1730   }
1731 
1732   // Patch the compiled method so that when execution returns to it we will
1733   // deopt the execution state and return to the interpreter.
1734   fr.deoptimize(thread);
1735 }
1736 
1737 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1738   // Deoptimize only if the frame comes from compile code.
1739   // Do not deoptimize the frame which is already patched
1740   // during the execution of the loops below.
1741   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1742     return;
1743   }
1744   ResourceMark rm;
1745   DeoptimizationMarker dm;
1746   deoptimize_single_frame(thread, fr, reason);
1747 }
1748 
1749 #if INCLUDE_JVMCI
1750 address Deoptimization::deoptimize_for_missing_exception_handler(CompiledMethod* cm) {
1751   // there is no exception handler for this pc => deoptimize
1752   cm->make_not_entrant();
1753 
1754   // Use Deoptimization::deoptimize for all of its side-effects:
1755   // gathering traps statistics, logging...
1756   // it also patches the return pc but we do not care about that
1757   // since we return a continuation to the deopt_blob below.
1758   JavaThread* thread = JavaThread::current();
1759   RegisterMap reg_map(thread, false);
1760   frame runtime_frame = thread->last_frame();
1761   frame caller_frame = runtime_frame.sender(&reg_map);
1762   assert(caller_frame.cb()->as_compiled_method_or_null() == cm, "expect top frame compiled method");
1763   vframe* vf = vframe::new_vframe(&caller_frame, &reg_map, thread);
1764   compiledVFrame* cvf = compiledVFrame::cast(vf);
1765   ScopeDesc* imm_scope = cvf->scope();
1766   MethodData* imm_mdo = get_method_data(thread, methodHandle(thread, imm_scope->method()), true);
1767   if (imm_mdo != NULL) {
1768     ProfileData* pdata = imm_mdo->allocate_bci_to_data(imm_scope->bci(), NULL);
1769     if (pdata != NULL && pdata->is_BitData()) {
1770       BitData* bit_data = (BitData*) pdata;
1771       bit_data->set_exception_seen();
1772     }
1773   }
1774 
1775   Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1776 
1777   MethodData* trap_mdo = get_method_data(thread, methodHandle(thread, cm->method()), true);
1778   if (trap_mdo != NULL) {
1779     trap_mdo->inc_trap_count(Deoptimization::Reason_not_compiled_exception_handler);
1780   }
1781 
1782   return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1783 }
1784 #endif
1785 
1786 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1787   assert(thread == Thread::current() ||
1788          thread->is_handshake_safe_for(Thread::current()) ||
1789          SafepointSynchronize::is_at_safepoint(),
1790          "can only deoptimize other thread at a safepoint/handshake");
1791   // Compute frame and register map based on thread and sp.
1792   RegisterMap reg_map(thread, false);
1793   frame fr = thread->last_frame();
1794   while (fr.id() != id) {
1795     fr = fr.sender(&reg_map);
1796   }
1797   deoptimize(thread, fr, reason);
1798 }
1799 
1800 
1801 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1802   Thread* current = Thread::current();
1803   if (thread == current || thread->is_handshake_safe_for(current)) {
1804     Deoptimization::deoptimize_frame_internal(thread, id, reason);
1805   } else {
1806     VM_DeoptimizeFrame deopt(thread, id, reason);
1807     VMThread::execute(&deopt);
1808   }
1809 }
1810 
1811 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1812   deoptimize_frame(thread, id, Reason_constraint);
1813 }
1814 
1815 // JVMTI PopFrame support
1816 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1817 {
1818   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1819 }
1820 JRT_END
1821 
1822 MethodData*
1823 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1824                                 bool create_if_missing) {
1825   JavaThread* THREAD = thread; // For exception macros.
1826   MethodData* mdo = m()->method_data();
1827   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1828     // Build an MDO.  Ignore errors like OutOfMemory;
1829     // that simply means we won't have an MDO to update.
1830     Method::build_interpreter_method_data(m, THREAD);
1831     if (HAS_PENDING_EXCEPTION) {
1832       // Only metaspace OOM is expected. No Java code executed.
1833       assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1834       CLEAR_PENDING_EXCEPTION;
1835     }
1836     mdo = m()->method_data();
1837   }
1838   return mdo;
1839 }
1840 
1841 #if COMPILER2_OR_JVMCI
1842 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1843   // In case of an unresolved klass entry, load the class.
1844   // This path is exercised from case _ldc in Parse::do_one_bytecode,
1845   // and probably nowhere else.
1846   // Even that case would benefit from simply re-interpreting the
1847   // bytecode, without paying special attention to the class index.
1848   // So this whole "class index" feature should probably be removed.
1849 
1850   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1851     Klass* tk = constant_pool->klass_at(index, THREAD);
1852     if (HAS_PENDING_EXCEPTION) {
1853       // Exception happened during classloading. We ignore the exception here, since it
1854       // is going to be rethrown since the current activation is going to be deoptimized and
1855       // the interpreter will re-execute the bytecode.
1856       // Do not clear probable Async Exceptions.
1857       CLEAR_PENDING_NONASYNC_EXCEPTION;
1858       // Class loading called java code which may have caused a stack
1859       // overflow. If the exception was thrown right before the return
1860       // to the runtime the stack is no longer guarded. Reguard the
1861       // stack otherwise if we return to the uncommon trap blob and the
1862       // stack bang causes a stack overflow we crash.
1863       JavaThread* jt = THREAD;
1864       bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1865       assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1866     }
1867     return;
1868   }
1869 
1870   assert(!constant_pool->tag_at(index).is_symbol(),
1871          "no symbolic names here, please");
1872 }
1873 
1874 #if INCLUDE_JFR
1875 
1876 class DeoptReasonSerializer : public JfrSerializer {
1877  public:
1878   void serialize(JfrCheckpointWriter& writer) {
1879     writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
1880     for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
1881       writer.write_key((u8)i);
1882       writer.write(Deoptimization::trap_reason_name(i));
1883     }
1884   }
1885 };
1886 
1887 class DeoptActionSerializer : public JfrSerializer {
1888  public:
1889   void serialize(JfrCheckpointWriter& writer) {
1890     static const u4 nof_actions = Deoptimization::Action_LIMIT;
1891     writer.write_count(nof_actions);
1892     for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
1893       writer.write_key(i);
1894       writer.write(Deoptimization::trap_action_name((int)i));
1895     }
1896   }
1897 };
1898 
1899 static void register_serializers() {
1900   static int critical_section = 0;
1901   if (1 == critical_section || Atomic::cmpxchg(&critical_section, 0, 1) == 1) {
1902     return;
1903   }
1904   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
1905   JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
1906 }
1907 
1908 static void post_deoptimization_event(CompiledMethod* nm,
1909                                       const Method* method,
1910                                       int trap_bci,
1911                                       int instruction,
1912                                       Deoptimization::DeoptReason reason,
1913                                       Deoptimization::DeoptAction action) {
1914   assert(nm != NULL, "invariant");
1915   assert(method != NULL, "invariant");
1916   if (EventDeoptimization::is_enabled()) {
1917     static bool serializers_registered = false;
1918     if (!serializers_registered) {
1919       register_serializers();
1920       serializers_registered = true;
1921     }
1922     EventDeoptimization event;
1923     event.set_compileId(nm->compile_id());
1924     event.set_compiler(nm->compiler_type());
1925     event.set_method(method);
1926     event.set_lineNumber(method->line_number_from_bci(trap_bci));
1927     event.set_bci(trap_bci);
1928     event.set_instruction(instruction);
1929     event.set_reason(reason);
1930     event.set_action(action);
1931     event.commit();
1932   }
1933 }
1934 
1935 #endif // INCLUDE_JFR
1936 
1937 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
1938   HandleMark hm(current);
1939 
1940   // uncommon_trap() is called at the beginning of the uncommon trap
1941   // handler. Note this fact before we start generating temporary frames
1942   // that can confuse an asynchronous stack walker. This counter is
1943   // decremented at the end of unpack_frames().
1944   current->inc_in_deopt_handler();
1945 
1946   // We need to update the map if we have biased locking.
1947 #if INCLUDE_JVMCI
1948   // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
1949   RegisterMap reg_map(current, true);
1950 #else
1951   RegisterMap reg_map(current, UseBiasedLocking);
1952 #endif
1953   frame stub_frame = current->last_frame();
1954   frame fr = stub_frame.sender(&reg_map);
1955   // Make sure the calling nmethod is not getting deoptimized and removed
1956   // before we are done with it.
1957   nmethodLocker nl(fr.pc());
1958 
1959   // Log a message
1960   Events::log_deopt_message(current, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
1961               trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
1962 
1963   {
1964     ResourceMark rm;
1965 
1966     DeoptReason reason = trap_request_reason(trap_request);
1967     DeoptAction action = trap_request_action(trap_request);
1968 #if INCLUDE_JVMCI
1969     int debug_id = trap_request_debug_id(trap_request);
1970 #endif
1971     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1972 
1973     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, current);
1974     compiledVFrame* cvf = compiledVFrame::cast(vf);
1975 
1976     CompiledMethod* nm = cvf->code();
1977 
1978     ScopeDesc*      trap_scope  = cvf->scope();
1979 
1980     bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
1981 
1982     if (TraceDeoptimization || is_receiver_constraint_failure) {
1983       ttyLocker ttyl;
1984       tty->print_cr("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"), trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
1985 #if INCLUDE_JVMCI
1986           , debug_id
1987 #endif
1988           );
1989     }
1990 
1991     methodHandle    trap_method(current, trap_scope->method());
1992     int             trap_bci    = trap_scope->bci();
1993 #if INCLUDE_JVMCI
1994     jlong           speculation = current->pending_failed_speculation();
1995     if (nm->is_compiled_by_jvmci()) {
1996       nm->as_nmethod()->update_speculation(current);
1997     } else {
1998       assert(speculation == 0, "There should not be a speculation for methods compiled by non-JVMCI compilers");
1999     }
2000 
2001     if (trap_bci == SynchronizationEntryBCI) {
2002       trap_bci = 0;
2003       current->set_pending_monitorenter(true);
2004     }
2005 
2006     if (reason == Deoptimization::Reason_transfer_to_interpreter) {
2007       current->set_pending_transfer_to_interpreter(true);
2008     }
2009 #endif
2010 
2011     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
2012     // Record this event in the histogram.
2013     gather_statistics(reason, action, trap_bc);
2014 
2015     // Ensure that we can record deopt. history:
2016     // Need MDO to record RTM code generation state.
2017     bool create_if_missing = ProfileTraps || UseCodeAging RTM_OPT_ONLY( || UseRTMLocking );
2018 
2019     methodHandle profiled_method;
2020 #if INCLUDE_JVMCI
2021     if (nm->is_compiled_by_jvmci()) {
2022       profiled_method = methodHandle(current, nm->method());
2023     } else {
2024       profiled_method = trap_method;
2025     }
2026 #else
2027     profiled_method = trap_method;
2028 #endif
2029 
2030     MethodData* trap_mdo =
2031       get_method_data(current, profiled_method, create_if_missing);
2032 
2033     JFR_ONLY(post_deoptimization_event(nm, trap_method(), trap_bci, trap_bc, reason, action);)
2034 
2035     // Log a message
2036     Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s",
2037                               trap_reason_name(reason), trap_action_name(action), p2i(fr.pc()),
2038                               trap_method->name_and_sig_as_C_string(), trap_bci, nm->compiler_name());
2039 
2040     // Print a bunch of diagnostics, if requested.
2041     if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
2042       ResourceMark rm;
2043       ttyLocker ttyl;
2044       char buf[100];
2045       if (xtty != NULL) {
2046         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT "' %s",
2047                          os::current_thread_id(),
2048                          format_trap_request(buf, sizeof(buf), trap_request));
2049 #if INCLUDE_JVMCI
2050         if (speculation != 0) {
2051           xtty->print(" speculation='" JLONG_FORMAT "'", speculation);
2052         }
2053 #endif
2054         nm->log_identity(xtty);
2055       }
2056       Symbol* class_name = NULL;
2057       bool unresolved = false;
2058       if (unloaded_class_index >= 0) {
2059         constantPoolHandle constants (current, trap_method->constants());
2060         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
2061           class_name = constants->klass_name_at(unloaded_class_index);
2062           unresolved = true;
2063           if (xtty != NULL)
2064             xtty->print(" unresolved='1'");
2065         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
2066           class_name = constants->symbol_at(unloaded_class_index);
2067         }
2068         if (xtty != NULL)
2069           xtty->name(class_name);
2070       }
2071       if (xtty != NULL && trap_mdo != NULL && (int)reason < (int)MethodData::_trap_hist_limit) {
2072         // Dump the relevant MDO state.
2073         // This is the deopt count for the current reason, any previous
2074         // reasons or recompiles seen at this point.
2075         int dcnt = trap_mdo->trap_count(reason);
2076         if (dcnt != 0)
2077           xtty->print(" count='%d'", dcnt);
2078         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
2079         int dos = (pdata == NULL)? 0: pdata->trap_state();
2080         if (dos != 0) {
2081           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
2082           if (trap_state_is_recompiled(dos)) {
2083             int recnt2 = trap_mdo->overflow_recompile_count();
2084             if (recnt2 != 0)
2085               xtty->print(" recompiles2='%d'", recnt2);
2086           }
2087         }
2088       }
2089       if (xtty != NULL) {
2090         xtty->stamp();
2091         xtty->end_head();
2092       }
2093       if (TraceDeoptimization) {  // make noise on the tty
2094         tty->print("Uncommon trap occurred in");
2095         nm->method()->print_short_name(tty);
2096         tty->print(" compiler=%s compile_id=%d", nm->compiler_name(), nm->compile_id());
2097 #if INCLUDE_JVMCI
2098         if (nm->is_nmethod()) {
2099           const char* installed_code_name = nm->as_nmethod()->jvmci_name();
2100           if (installed_code_name != NULL) {
2101             tty->print(" (JVMCI: installed code name=%s) ", installed_code_name);
2102           }
2103         }
2104 #endif
2105         tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
2106                    p2i(fr.pc()),
2107                    os::current_thread_id(),
2108                    trap_reason_name(reason),
2109                    trap_action_name(action),
2110                    unloaded_class_index
2111 #if INCLUDE_JVMCI
2112                    , debug_id
2113 #endif
2114                    );
2115         if (class_name != NULL) {
2116           tty->print(unresolved ? " unresolved class: " : " symbol: ");
2117           class_name->print_symbol_on(tty);
2118         }
2119         tty->cr();
2120       }
2121       if (xtty != NULL) {
2122         // Log the precise location of the trap.
2123         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2124           xtty->begin_elem("jvms bci='%d'", sd->bci());
2125           xtty->method(sd->method());
2126           xtty->end_elem();
2127           if (sd->is_top())  break;
2128         }
2129         xtty->tail("uncommon_trap");
2130       }
2131     }
2132     // (End diagnostic printout.)
2133 
2134     if (is_receiver_constraint_failure) {
2135       fatal("missing receiver type check");
2136     }
2137 
2138     // Load class if necessary
2139     if (unloaded_class_index >= 0) {
2140       constantPoolHandle constants(current, trap_method->constants());
2141       load_class_by_index(constants, unloaded_class_index, THREAD);
2142     }
2143 
2144     // Flush the nmethod if necessary and desirable.
2145     //
2146     // We need to avoid situations where we are re-flushing the nmethod
2147     // because of a hot deoptimization site.  Repeated flushes at the same
2148     // point need to be detected by the compiler and avoided.  If the compiler
2149     // cannot avoid them (or has a bug and "refuses" to avoid them), this
2150     // module must take measures to avoid an infinite cycle of recompilation
2151     // and deoptimization.  There are several such measures:
2152     //
2153     //   1. If a recompilation is ordered a second time at some site X
2154     //   and for the same reason R, the action is adjusted to 'reinterpret',
2155     //   to give the interpreter time to exercise the method more thoroughly.
2156     //   If this happens, the method's overflow_recompile_count is incremented.
2157     //
2158     //   2. If the compiler fails to reduce the deoptimization rate, then
2159     //   the method's overflow_recompile_count will begin to exceed the set
2160     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
2161     //   is adjusted to 'make_not_compilable', and the method is abandoned
2162     //   to the interpreter.  This is a performance hit for hot methods,
2163     //   but is better than a disastrous infinite cycle of recompilations.
2164     //   (Actually, only the method containing the site X is abandoned.)
2165     //
2166     //   3. In parallel with the previous measures, if the total number of
2167     //   recompilations of a method exceeds the much larger set limit
2168     //   PerMethodRecompilationCutoff, the method is abandoned.
2169     //   This should only happen if the method is very large and has
2170     //   many "lukewarm" deoptimizations.  The code which enforces this
2171     //   limit is elsewhere (class nmethod, class Method).
2172     //
2173     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2174     // to recompile at each bytecode independently of the per-BCI cutoff.
2175     //
2176     // The decision to update code is up to the compiler, and is encoded
2177     // in the Action_xxx code.  If the compiler requests Action_none
2178     // no trap state is changed, no compiled code is changed, and the
2179     // computation suffers along in the interpreter.
2180     //
2181     // The other action codes specify various tactics for decompilation
2182     // and recompilation.  Action_maybe_recompile is the loosest, and
2183     // allows the compiled code to stay around until enough traps are seen,
2184     // and until the compiler gets around to recompiling the trapping method.
2185     //
2186     // The other actions cause immediate removal of the present code.
2187 
2188     // Traps caused by injected profile shouldn't pollute trap counts.
2189     bool injected_profile_trap = trap_method->has_injected_profile() &&
2190                                  (reason == Reason_intrinsic || reason == Reason_unreached);
2191 
2192     bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2193     bool make_not_entrant = false;
2194     bool make_not_compilable = false;
2195     bool reprofile = false;
2196     switch (action) {
2197     case Action_none:
2198       // Keep the old code.
2199       update_trap_state = false;
2200       break;
2201     case Action_maybe_recompile:
2202       // Do not need to invalidate the present code, but we can
2203       // initiate another
2204       // Start compiler without (necessarily) invalidating the nmethod.
2205       // The system will tolerate the old code, but new code should be
2206       // generated when possible.
2207       break;
2208     case Action_reinterpret:
2209       // Go back into the interpreter for a while, and then consider
2210       // recompiling form scratch.
2211       make_not_entrant = true;
2212       // Reset invocation counter for outer most method.
2213       // This will allow the interpreter to exercise the bytecodes
2214       // for a while before recompiling.
2215       // By contrast, Action_make_not_entrant is immediate.
2216       //
2217       // Note that the compiler will track null_check, null_assert,
2218       // range_check, and class_check events and log them as if they
2219       // had been traps taken from compiled code.  This will update
2220       // the MDO trap history so that the next compilation will
2221       // properly detect hot trap sites.
2222       reprofile = true;
2223       break;
2224     case Action_make_not_entrant:
2225       // Request immediate recompilation, and get rid of the old code.
2226       // Make them not entrant, so next time they are called they get
2227       // recompiled.  Unloaded classes are loaded now so recompile before next
2228       // time they are called.  Same for uninitialized.  The interpreter will
2229       // link the missing class, if any.
2230       make_not_entrant = true;
2231       break;
2232     case Action_make_not_compilable:
2233       // Give up on compiling this method at all.
2234       make_not_entrant = true;
2235       make_not_compilable = true;
2236       break;
2237     default:
2238       ShouldNotReachHere();
2239     }
2240 
2241     // Setting +ProfileTraps fixes the following, on all platforms:
2242     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
2243     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2244     // recompile relies on a MethodData* to record heroic opt failures.
2245 
2246     // Whether the interpreter is producing MDO data or not, we also need
2247     // to use the MDO to detect hot deoptimization points and control
2248     // aggressive optimization.
2249     bool inc_recompile_count = false;
2250     ProfileData* pdata = NULL;
2251     if (ProfileTraps && CompilerConfig::is_c2_or_jvmci_compiler_enabled() && update_trap_state && trap_mdo != NULL) {
2252       assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2253       uint this_trap_count = 0;
2254       bool maybe_prior_trap = false;
2255       bool maybe_prior_recompile = false;
2256       pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
2257 #if INCLUDE_JVMCI
2258                                    nm->is_compiled_by_jvmci() && nm->is_osr_method(),
2259 #endif
2260                                    nm->method(),
2261                                    //outputs:
2262                                    this_trap_count,
2263                                    maybe_prior_trap,
2264                                    maybe_prior_recompile);
2265       // Because the interpreter also counts null, div0, range, and class
2266       // checks, these traps from compiled code are double-counted.
2267       // This is harmless; it just means that the PerXTrapLimit values
2268       // are in effect a little smaller than they look.
2269 
2270       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2271       if (per_bc_reason != Reason_none) {
2272         // Now take action based on the partially known per-BCI history.
2273         if (maybe_prior_trap
2274             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2275           // If there are too many traps at this BCI, force a recompile.
2276           // This will allow the compiler to see the limit overflow, and
2277           // take corrective action, if possible.  The compiler generally
2278           // does not use the exact PerBytecodeTrapLimit value, but instead
2279           // changes its tactics if it sees any traps at all.  This provides
2280           // a little hysteresis, delaying a recompile until a trap happens
2281           // several times.
2282           //
2283           // Actually, since there is only one bit of counter per BCI,
2284           // the possible per-BCI counts are {0,1,(per-method count)}.
2285           // This produces accurate results if in fact there is only
2286           // one hot trap site, but begins to get fuzzy if there are
2287           // many sites.  For example, if there are ten sites each
2288           // trapping two or more times, they each get the blame for
2289           // all of their traps.
2290           make_not_entrant = true;
2291         }
2292 
2293         // Detect repeated recompilation at the same BCI, and enforce a limit.
2294         if (make_not_entrant && maybe_prior_recompile) {
2295           // More than one recompile at this point.
2296           inc_recompile_count = maybe_prior_trap;
2297         }
2298       } else {
2299         // For reasons which are not recorded per-bytecode, we simply
2300         // force recompiles unconditionally.
2301         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2302         make_not_entrant = true;
2303       }
2304 
2305       // Go back to the compiler if there are too many traps in this method.
2306       if (this_trap_count >= per_method_trap_limit(reason)) {
2307         // If there are too many traps in this method, force a recompile.
2308         // This will allow the compiler to see the limit overflow, and
2309         // take corrective action, if possible.
2310         // (This condition is an unlikely backstop only, because the
2311         // PerBytecodeTrapLimit is more likely to take effect first,
2312         // if it is applicable.)
2313         make_not_entrant = true;
2314       }
2315 
2316       // Here's more hysteresis:  If there has been a recompile at
2317       // this trap point already, run the method in the interpreter
2318       // for a while to exercise it more thoroughly.
2319       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2320         reprofile = true;
2321       }
2322     }
2323 
2324     // Take requested actions on the method:
2325 
2326     // Recompile
2327     if (make_not_entrant) {
2328       if (!nm->make_not_entrant()) {
2329         return; // the call did not change nmethod's state
2330       }
2331 
2332       if (pdata != NULL) {
2333         // Record the recompilation event, if any.
2334         int tstate0 = pdata->trap_state();
2335         int tstate1 = trap_state_set_recompiled(tstate0, true);
2336         if (tstate1 != tstate0)
2337           pdata->set_trap_state(tstate1);
2338       }
2339 
2340 #if INCLUDE_RTM_OPT
2341       // Restart collecting RTM locking abort statistic if the method
2342       // is recompiled for a reason other than RTM state change.
2343       // Assume that in new recompiled code the statistic could be different,
2344       // for example, due to different inlining.
2345       if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
2346           UseRTMDeopt && (nm->as_nmethod()->rtm_state() != ProfileRTM)) {
2347         trap_mdo->atomic_set_rtm_state(ProfileRTM);
2348       }
2349 #endif
2350       // For code aging we count traps separately here, using make_not_entrant()
2351       // as a guard against simultaneous deopts in multiple threads.
2352       if (reason == Reason_tenured && trap_mdo != NULL) {
2353         trap_mdo->inc_tenure_traps();
2354       }
2355     }
2356 
2357     if (inc_recompile_count) {
2358       trap_mdo->inc_overflow_recompile_count();
2359       if ((uint)trap_mdo->overflow_recompile_count() >
2360           (uint)PerBytecodeRecompilationCutoff) {
2361         // Give up on the method containing the bad BCI.
2362         if (trap_method() == nm->method()) {
2363           make_not_compilable = true;
2364         } else {
2365           trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2366           // But give grace to the enclosing nm->method().
2367         }
2368       }
2369     }
2370 
2371     // Reprofile
2372     if (reprofile) {
2373       CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2374     }
2375 
2376     // Give up compiling
2377     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2378       assert(make_not_entrant, "consistent");
2379       nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2380     }
2381 
2382   } // Free marked resources
2383 
2384 }
2385 JRT_END
2386 
2387 ProfileData*
2388 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2389                                          int trap_bci,
2390                                          Deoptimization::DeoptReason reason,
2391                                          bool update_total_trap_count,
2392 #if INCLUDE_JVMCI
2393                                          bool is_osr,
2394 #endif
2395                                          Method* compiled_method,
2396                                          //outputs:
2397                                          uint& ret_this_trap_count,
2398                                          bool& ret_maybe_prior_trap,
2399                                          bool& ret_maybe_prior_recompile) {
2400   bool maybe_prior_trap = false;
2401   bool maybe_prior_recompile = false;
2402   uint this_trap_count = 0;
2403   if (update_total_trap_count) {
2404     uint idx = reason;
2405 #if INCLUDE_JVMCI
2406     if (is_osr) {
2407       // Upper half of history array used for traps in OSR compilations
2408       idx += Reason_TRAP_HISTORY_LENGTH;
2409     }
2410 #endif
2411     uint prior_trap_count = trap_mdo->trap_count(idx);
2412     this_trap_count  = trap_mdo->inc_trap_count(idx);
2413 
2414     // If the runtime cannot find a place to store trap history,
2415     // it is estimated based on the general condition of the method.
2416     // If the method has ever been recompiled, or has ever incurred
2417     // a trap with the present reason , then this BCI is assumed
2418     // (pessimistically) to be the culprit.
2419     maybe_prior_trap      = (prior_trap_count != 0);
2420     maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2421   }
2422   ProfileData* pdata = NULL;
2423 
2424 
2425   // For reasons which are recorded per bytecode, we check per-BCI data.
2426   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2427   assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
2428   if (per_bc_reason != Reason_none) {
2429     // Find the profile data for this BCI.  If there isn't one,
2430     // try to allocate one from the MDO's set of spares.
2431     // This will let us detect a repeated trap at this point.
2432     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
2433 
2434     if (pdata != NULL) {
2435       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2436         if (LogCompilation && xtty != NULL) {
2437           ttyLocker ttyl;
2438           // no more room for speculative traps in this MDO
2439           xtty->elem("speculative_traps_oom");
2440         }
2441       }
2442       // Query the trap state of this profile datum.
2443       int tstate0 = pdata->trap_state();
2444       if (!trap_state_has_reason(tstate0, per_bc_reason))
2445         maybe_prior_trap = false;
2446       if (!trap_state_is_recompiled(tstate0))
2447         maybe_prior_recompile = false;
2448 
2449       // Update the trap state of this profile datum.
2450       int tstate1 = tstate0;
2451       // Record the reason.
2452       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2453       // Store the updated state on the MDO, for next time.
2454       if (tstate1 != tstate0)
2455         pdata->set_trap_state(tstate1);
2456     } else {
2457       if (LogCompilation && xtty != NULL) {
2458         ttyLocker ttyl;
2459         // Missing MDP?  Leave a small complaint in the log.
2460         xtty->elem("missing_mdp bci='%d'", trap_bci);
2461       }
2462     }
2463   }
2464 
2465   // Return results:
2466   ret_this_trap_count = this_trap_count;
2467   ret_maybe_prior_trap = maybe_prior_trap;
2468   ret_maybe_prior_recompile = maybe_prior_recompile;
2469   return pdata;
2470 }
2471 
2472 void
2473 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2474   ResourceMark rm;
2475   // Ignored outputs:
2476   uint ignore_this_trap_count;
2477   bool ignore_maybe_prior_trap;
2478   bool ignore_maybe_prior_recompile;
2479   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2480   // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2481   bool update_total_counts = true JVMCI_ONLY( && !UseJVMCICompiler);
2482   query_update_method_data(trap_mdo, trap_bci,
2483                            (DeoptReason)reason,
2484                            update_total_counts,
2485 #if INCLUDE_JVMCI
2486                            false,
2487 #endif
2488                            NULL,
2489                            ignore_this_trap_count,
2490                            ignore_maybe_prior_trap,
2491                            ignore_maybe_prior_recompile);
2492 }
2493 
2494 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode) {
2495   // Enable WXWrite: current function is called from methods compiled by C2 directly
2496   MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2497 
2498   if (TraceDeoptimization) {
2499     tty->print("Uncommon trap ");
2500   }
2501   // Still in Java no safepoints
2502   {
2503     // This enters VM and may safepoint
2504     uncommon_trap_inner(current, trap_request);
2505   }
2506   HandleMark hm(current);
2507   return fetch_unroll_info_helper(current, exec_mode);
2508 }
2509 
2510 // Local derived constants.
2511 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2512 const int DS_REASON_MASK   = ((uint)DataLayout::trap_mask) >> 1;
2513 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2514 
2515 //---------------------------trap_state_reason---------------------------------
2516 Deoptimization::DeoptReason
2517 Deoptimization::trap_state_reason(int trap_state) {
2518   // This assert provides the link between the width of DataLayout::trap_bits
2519   // and the encoding of "recorded" reasons.  It ensures there are enough
2520   // bits to store all needed reasons in the per-BCI MDO profile.
2521   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2522   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2523   trap_state -= recompile_bit;
2524   if (trap_state == DS_REASON_MASK) {
2525     return Reason_many;
2526   } else {
2527     assert((int)Reason_none == 0, "state=0 => Reason_none");
2528     return (DeoptReason)trap_state;
2529   }
2530 }
2531 //-------------------------trap_state_has_reason-------------------------------
2532 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2533   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2534   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2535   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2536   trap_state -= recompile_bit;
2537   if (trap_state == DS_REASON_MASK) {
2538     return -1;  // true, unspecifically (bottom of state lattice)
2539   } else if (trap_state == reason) {
2540     return 1;   // true, definitely
2541   } else if (trap_state == 0) {
2542     return 0;   // false, definitely (top of state lattice)
2543   } else {
2544     return 0;   // false, definitely
2545   }
2546 }
2547 //-------------------------trap_state_add_reason-------------------------------
2548 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2549   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2550   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2551   trap_state -= recompile_bit;
2552   if (trap_state == DS_REASON_MASK) {
2553     return trap_state + recompile_bit;     // already at state lattice bottom
2554   } else if (trap_state == reason) {
2555     return trap_state + recompile_bit;     // the condition is already true
2556   } else if (trap_state == 0) {
2557     return reason + recompile_bit;          // no condition has yet been true
2558   } else {
2559     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
2560   }
2561 }
2562 //-----------------------trap_state_is_recompiled------------------------------
2563 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2564   return (trap_state & DS_RECOMPILE_BIT) != 0;
2565 }
2566 //-----------------------trap_state_set_recompiled-----------------------------
2567 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2568   if (z)  return trap_state |  DS_RECOMPILE_BIT;
2569   else    return trap_state & ~DS_RECOMPILE_BIT;
2570 }
2571 //---------------------------format_trap_state---------------------------------
2572 // This is used for debugging and diagnostics, including LogFile output.
2573 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2574                                               int trap_state) {
2575   assert(buflen > 0, "sanity");
2576   DeoptReason reason      = trap_state_reason(trap_state);
2577   bool        recomp_flag = trap_state_is_recompiled(trap_state);
2578   // Re-encode the state from its decoded components.
2579   int decoded_state = 0;
2580   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2581     decoded_state = trap_state_add_reason(decoded_state, reason);
2582   if (recomp_flag)
2583     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2584   // If the state re-encodes properly, format it symbolically.
2585   // Because this routine is used for debugging and diagnostics,
2586   // be robust even if the state is a strange value.
2587   size_t len;
2588   if (decoded_state != trap_state) {
2589     // Random buggy state that doesn't decode??
2590     len = jio_snprintf(buf, buflen, "#%d", trap_state);
2591   } else {
2592     len = jio_snprintf(buf, buflen, "%s%s",
2593                        trap_reason_name(reason),
2594                        recomp_flag ? " recompiled" : "");
2595   }
2596   return buf;
2597 }
2598 
2599 
2600 //--------------------------------statics--------------------------------------
2601 const char* Deoptimization::_trap_reason_name[] = {
2602   // Note:  Keep this in sync. with enum DeoptReason.
2603   "none",
2604   "null_check",
2605   "null_assert" JVMCI_ONLY("_or_unreached0"),
2606   "range_check",
2607   "class_check",
2608   "array_check",
2609   "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2610   "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2611   "profile_predicate",
2612   "unloaded",
2613   "uninitialized",
2614   "initialized",
2615   "unreached",
2616   "unhandled",
2617   "constraint",
2618   "div0_check",
2619   "age",
2620   "predicate",
2621   "loop_limit_check",
2622   "speculate_class_check",
2623   "speculate_null_check",
2624   "speculate_null_assert",
2625   "rtm_state_change",
2626   "unstable_if",
2627   "unstable_fused_if",
2628   "receiver_constraint",
2629 #if INCLUDE_JVMCI
2630   "aliasing",
2631   "transfer_to_interpreter",
2632   "not_compiled_exception_handler",
2633   "unresolved",
2634   "jsr_mismatch",
2635 #endif
2636   "tenured"
2637 };
2638 const char* Deoptimization::_trap_action_name[] = {
2639   // Note:  Keep this in sync. with enum DeoptAction.
2640   "none",
2641   "maybe_recompile",
2642   "reinterpret",
2643   "make_not_entrant",
2644   "make_not_compilable"
2645 };
2646 
2647 const char* Deoptimization::trap_reason_name(int reason) {
2648   // Check that every reason has a name
2649   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2650 
2651   if (reason == Reason_many)  return "many";
2652   if ((uint)reason < Reason_LIMIT)
2653     return _trap_reason_name[reason];
2654   static char buf[20];
2655   sprintf(buf, "reason%d", reason);
2656   return buf;
2657 }
2658 const char* Deoptimization::trap_action_name(int action) {
2659   // Check that every action has a name
2660   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2661 
2662   if ((uint)action < Action_LIMIT)
2663     return _trap_action_name[action];
2664   static char buf[20];
2665   sprintf(buf, "action%d", action);
2666   return buf;
2667 }
2668 
2669 // This is used for debugging and diagnostics, including LogFile output.
2670 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2671                                                 int trap_request) {
2672   jint unloaded_class_index = trap_request_index(trap_request);
2673   const char* reason = trap_reason_name(trap_request_reason(trap_request));
2674   const char* action = trap_action_name(trap_request_action(trap_request));
2675 #if INCLUDE_JVMCI
2676   int debug_id = trap_request_debug_id(trap_request);
2677 #endif
2678   size_t len;
2679   if (unloaded_class_index < 0) {
2680     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2681                        reason, action
2682 #if INCLUDE_JVMCI
2683                        ,debug_id
2684 #endif
2685                        );
2686   } else {
2687     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2688                        reason, action, unloaded_class_index
2689 #if INCLUDE_JVMCI
2690                        ,debug_id
2691 #endif
2692                        );
2693   }
2694   return buf;
2695 }
2696 
2697 juint Deoptimization::_deoptimization_hist
2698         [Deoptimization::Reason_LIMIT]
2699     [1 + Deoptimization::Action_LIMIT]
2700         [Deoptimization::BC_CASE_LIMIT]
2701   = {0};
2702 
2703 enum {
2704   LSB_BITS = 8,
2705   LSB_MASK = right_n_bits(LSB_BITS)
2706 };
2707 
2708 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2709                                        Bytecodes::Code bc) {
2710   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2711   assert(action >= 0 && action < Action_LIMIT, "oob");
2712   _deoptimization_hist[Reason_none][0][0] += 1;  // total
2713   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
2714   juint* cases = _deoptimization_hist[reason][1+action];
2715   juint* bc_counter_addr = NULL;
2716   juint  bc_counter      = 0;
2717   // Look for an unused counter, or an exact match to this BC.
2718   if (bc != Bytecodes::_illegal) {
2719     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2720       juint* counter_addr = &cases[bc_case];
2721       juint  counter = *counter_addr;
2722       if ((counter == 0 && bc_counter_addr == NULL)
2723           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2724         // this counter is either free or is already devoted to this BC
2725         bc_counter_addr = counter_addr;
2726         bc_counter = counter | bc;
2727       }
2728     }
2729   }
2730   if (bc_counter_addr == NULL) {
2731     // Overflow, or no given bytecode.
2732     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2733     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
2734   }
2735   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2736 }
2737 
2738 jint Deoptimization::total_deoptimization_count() {
2739   return _deoptimization_hist[Reason_none][0][0];
2740 }
2741 
2742 void Deoptimization::print_statistics() {
2743   juint total = total_deoptimization_count();
2744   juint account = total;
2745   if (total != 0) {
2746     ttyLocker ttyl;
2747     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
2748     tty->print_cr("Deoptimization traps recorded:");
2749     #define PRINT_STAT_LINE(name, r) \
2750       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2751     PRINT_STAT_LINE("total", total);
2752     // For each non-zero entry in the histogram, print the reason,
2753     // the action, and (if specifically known) the type of bytecode.
2754     for (int reason = 0; reason < Reason_LIMIT; reason++) {
2755       for (int action = 0; action < Action_LIMIT; action++) {
2756         juint* cases = _deoptimization_hist[reason][1+action];
2757         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2758           juint counter = cases[bc_case];
2759           if (counter != 0) {
2760             char name[1*K];
2761             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2762             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2763               bc = Bytecodes::_illegal;
2764             sprintf(name, "%s/%s/%s",
2765                     trap_reason_name(reason),
2766                     trap_action_name(action),
2767                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2768             juint r = counter >> LSB_BITS;
2769             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2770             account -= r;
2771           }
2772         }
2773       }
2774     }
2775     if (account != 0) {
2776       PRINT_STAT_LINE("unaccounted", account);
2777     }
2778     #undef PRINT_STAT_LINE
2779     if (xtty != NULL)  xtty->tail("statistics");
2780   }
2781 }
2782 
2783 #else // COMPILER2_OR_JVMCI
2784 
2785 
2786 // Stubs for C1 only system.
2787 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2788   return false;
2789 }
2790 
2791 const char* Deoptimization::trap_reason_name(int reason) {
2792   return "unknown";
2793 }
2794 
2795 void Deoptimization::print_statistics() {
2796   // no output
2797 }
2798 
2799 void
2800 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2801   // no udpate
2802 }
2803 
2804 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2805   return 0;
2806 }
2807 
2808 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2809                                        Bytecodes::Code bc) {
2810   // no update
2811 }
2812 
2813 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2814                                               int trap_state) {
2815   jio_snprintf(buf, buflen, "#%d", trap_state);
2816   return buf;
2817 }
2818 
2819 #endif // COMPILER2_OR_JVMCI