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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 
      5 #include "src/v8.h"
      6 
      7 #include "src/accessors.h"
      8 #include "src/api.h"
      9 #include "src/arguments.h"
     10 #include "src/base/bits.h"
     11 #include "src/codegen.h"
     12 #include "src/conversions.h"
     13 #include "src/execution.h"
     14 #include "src/ic/call-optimization.h"
     15 #include "src/ic/handler-compiler.h"
     16 #include "src/ic/ic-inl.h"
     17 #include "src/ic/ic-compiler.h"
     18 #include "src/ic/stub-cache.h"
     19 #include "src/prototype.h"
     20 #include "src/runtime.h"
     21 
     22 namespace v8 {
     23 namespace internal {
     24 
     25 char IC::TransitionMarkFromState(IC::State state) {
     26   switch (state) {
     27     case UNINITIALIZED:
     28       return '0';
     29     case PREMONOMORPHIC:
     30       return '.';
     31     case MONOMORPHIC:
     32       return '1';
     33     case PROTOTYPE_FAILURE:
     34       return '^';
     35     case POLYMORPHIC:
     36       return 'P';
     37     case MEGAMORPHIC:
     38       return 'N';
     39     case GENERIC:
     40       return 'G';
     41 
     42     // We never see the debugger states here, because the state is
     43     // computed from the original code - not the patched code. Let
     44     // these cases fall through to the unreachable code below.
     45     case DEBUG_STUB:
     46       break;
     47     // Type-vector-based ICs resolve state to one of the above.
     48     case DEFAULT:
     49       break;
     50   }
     51   UNREACHABLE();
     52   return 0;
     53 }
     54 
     55 
     56 const char* GetTransitionMarkModifier(KeyedAccessStoreMode mode) {
     57   if (mode == STORE_NO_TRANSITION_HANDLE_COW) return ".COW";
     58   if (mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
     59     return ".IGNORE_OOB";
     60   }
     61   if (IsGrowStoreMode(mode)) return ".GROW";
     62   return "";
     63 }
     64 
     65 
     66 #ifdef DEBUG
     67 
     68 #define TRACE_GENERIC_IC(isolate, type, reason)                \
     69   do {                                                         \
     70     if (FLAG_trace_ic) {                                       \
     71       PrintF("[%s patching generic stub in ", type);           \
     72       JavaScriptFrame::PrintTop(isolate, stdout, false, true); \
     73       PrintF(" (%s)]\n", reason);                              \
     74     }                                                          \
     75   } while (false)
     76 
     77 #else
     78 
     79 #define TRACE_GENERIC_IC(isolate, type, reason)      \
     80   do {                                               \
     81     if (FLAG_trace_ic) {                             \
     82       PrintF("[%s patching generic stub in ", type); \
     83       PrintF("(see below) (%s)]\n", reason);         \
     84     }                                                \
     85   } while (false)
     86 
     87 #endif  // DEBUG
     88 
     89 
     90 void IC::TraceIC(const char* type, Handle<Object> name) {
     91   if (FLAG_trace_ic) {
     92     Code* new_target = raw_target();
     93     State new_state = new_target->ic_state();
     94     TraceIC(type, name, state(), new_state);
     95   }
     96 }
     97 
     98 
     99 void IC::TraceIC(const char* type, Handle<Object> name, State old_state,
    100                  State new_state) {
    101   if (FLAG_trace_ic) {
    102     Code* new_target = raw_target();
    103     PrintF("[%s%s in ", new_target->is_keyed_stub() ? "Keyed" : "", type);
    104 
    105     // TODO(jkummerow): Add support for "apply". The logic is roughly:
    106     // marker = [fp_ + kMarkerOffset];
    107     // if marker is smi and marker.value == INTERNAL and
    108     //     the frame's code == builtin(Builtins::kFunctionApply):
    109     // then print "apply from" and advance one frame
    110 
    111     Object* maybe_function =
    112         Memory::Object_at(fp_ + JavaScriptFrameConstants::kFunctionOffset);
    113     if (maybe_function->IsJSFunction()) {
    114       JSFunction* function = JSFunction::cast(maybe_function);
    115       JavaScriptFrame::PrintFunctionAndOffset(function, function->code(), pc(),
    116                                               stdout, true);
    117     }
    118 
    119     ExtraICState extra_state = new_target->extra_ic_state();
    120     const char* modifier = "";
    121     if (new_target->kind() == Code::KEYED_STORE_IC) {
    122       modifier = GetTransitionMarkModifier(
    123           KeyedStoreIC::GetKeyedAccessStoreMode(extra_state));
    124     }
    125     PrintF(" (%c->%c%s)", TransitionMarkFromState(old_state),
    126            TransitionMarkFromState(new_state), modifier);
    127 #ifdef OBJECT_PRINT
    128     OFStream os(stdout);
    129     name->Print(os);
    130 #else
    131     name->ShortPrint(stdout);
    132 #endif
    133     PrintF("]\n");
    134   }
    135 }
    136 
    137 #define TRACE_IC(type, name) TraceIC(type, name)
    138 #define TRACE_VECTOR_IC(type, name, old_state, new_state) \
    139   TraceIC(type, name, old_state, new_state)
    140 
    141 IC::IC(FrameDepth depth, Isolate* isolate)
    142     : isolate_(isolate), target_set_(false), target_maps_set_(false) {
    143   // To improve the performance of the (much used) IC code, we unfold a few
    144   // levels of the stack frame iteration code. This yields a ~35% speedup when
    145   // running DeltaBlue and a ~25% speedup of gbemu with the '--nouse-ic' flag.
    146   const Address entry = Isolate::c_entry_fp(isolate->thread_local_top());
    147   Address constant_pool = NULL;
    148   if (FLAG_enable_ool_constant_pool) {
    149     constant_pool =
    150         Memory::Address_at(entry + ExitFrameConstants::kConstantPoolOffset);
    151   }
    152   Address* pc_address =
    153       reinterpret_cast<Address*>(entry + ExitFrameConstants::kCallerPCOffset);
    154   Address fp = Memory::Address_at(entry + ExitFrameConstants::kCallerFPOffset);
    155   // If there's another JavaScript frame on the stack or a
    156   // StubFailureTrampoline, we need to look one frame further down the stack to
    157   // find the frame pointer and the return address stack slot.
    158   if (depth == EXTRA_CALL_FRAME) {
    159     if (FLAG_enable_ool_constant_pool) {
    160       constant_pool =
    161           Memory::Address_at(fp + StandardFrameConstants::kConstantPoolOffset);
    162     }
    163     const int kCallerPCOffset = StandardFrameConstants::kCallerPCOffset;
    164     pc_address = reinterpret_cast<Address*>(fp + kCallerPCOffset);
    165     fp = Memory::Address_at(fp + StandardFrameConstants::kCallerFPOffset);
    166   }
    167 #ifdef DEBUG
    168   StackFrameIterator it(isolate);
    169   for (int i = 0; i < depth + 1; i++) it.Advance();
    170   StackFrame* frame = it.frame();
    171   DCHECK(fp == frame->fp() && pc_address == frame->pc_address());
    172 #endif
    173   fp_ = fp;
    174   if (FLAG_enable_ool_constant_pool) {
    175     raw_constant_pool_ = handle(
    176         ConstantPoolArray::cast(reinterpret_cast<Object*>(constant_pool)),
    177         isolate);
    178   }
    179   pc_address_ = StackFrame::ResolveReturnAddressLocation(pc_address);
    180   target_ = handle(raw_target(), isolate);
    181   state_ = target_->ic_state();
    182   kind_ = target_->kind();
    183   extra_ic_state_ = target_->extra_ic_state();
    184 }
    185 
    186 
    187 SharedFunctionInfo* IC::GetSharedFunctionInfo() const {
    188   // Compute the JavaScript frame for the frame pointer of this IC
    189   // structure. We need this to be able to find the function
    190   // corresponding to the frame.
    191   StackFrameIterator it(isolate());
    192   while (it.frame()->fp() != this->fp()) it.Advance();
    193   JavaScriptFrame* frame = JavaScriptFrame::cast(it.frame());
    194   // Find the function on the stack and both the active code for the
    195   // function and the original code.
    196   JSFunction* function = frame->function();
    197   return function->shared();
    198 }
    199 
    200 
    201 Code* IC::GetCode() const {
    202   HandleScope scope(isolate());
    203   Handle<SharedFunctionInfo> shared(GetSharedFunctionInfo(), isolate());
    204   Code* code = shared->code();
    205   return code;
    206 }
    207 
    208 
    209 Code* IC::GetOriginalCode() const {
    210   HandleScope scope(isolate());
    211   Handle<SharedFunctionInfo> shared(GetSharedFunctionInfo(), isolate());
    212   DCHECK(Debug::HasDebugInfo(shared));
    213   Code* original_code = Debug::GetDebugInfo(shared)->original_code();
    214   DCHECK(original_code->IsCode());
    215   return original_code;
    216 }
    217 
    218 
    219 static void LookupForRead(LookupIterator* it) {
    220   for (; it->IsFound(); it->Next()) {
    221     switch (it->state()) {
    222       case LookupIterator::NOT_FOUND:
    223       case LookupIterator::TRANSITION:
    224         UNREACHABLE();
    225       case LookupIterator::JSPROXY:
    226         return;
    227       case LookupIterator::INTERCEPTOR: {
    228         // If there is a getter, return; otherwise loop to perform the lookup.
    229         Handle<JSObject> holder = it->GetHolder<JSObject>();
    230         if (!holder->GetNamedInterceptor()->getter()->IsUndefined()) {
    231           return;
    232         }
    233         break;
    234       }
    235       case LookupIterator::ACCESS_CHECK:
    236         // PropertyHandlerCompiler::CheckPrototypes() knows how to emit
    237         // access checks for global proxies.
    238         if (it->GetHolder<JSObject>()->IsJSGlobalProxy() &&
    239             it->HasAccess(v8::ACCESS_GET)) {
    240           break;
    241         }
    242         return;
    243       case LookupIterator::ACCESSOR:
    244       case LookupIterator::DATA:
    245         return;
    246     }
    247   }
    248 }
    249 
    250 
    251 bool IC::TryRemoveInvalidPrototypeDependentStub(Handle<Object> receiver,
    252                                                 Handle<String> name) {
    253   if (!IsNameCompatibleWithPrototypeFailure(name)) return false;
    254   Handle<Map> receiver_map = TypeToMap(*receiver_type(), isolate());
    255   maybe_handler_ = target()->FindHandlerForMap(*receiver_map);
    256 
    257   // The current map wasn't handled yet. There's no reason to stay monomorphic,
    258   // *unless* we're moving from a deprecated map to its replacement, or
    259   // to a more general elements kind.
    260   // TODO(verwaest): Check if the current map is actually what the old map
    261   // would transition to.
    262   if (maybe_handler_.is_null()) {
    263     if (!receiver_map->IsJSObjectMap()) return false;
    264     Map* first_map = FirstTargetMap();
    265     if (first_map == NULL) return false;
    266     Handle<Map> old_map(first_map);
    267     if (old_map->is_deprecated()) return true;
    268     if (IsMoreGeneralElementsKindTransition(old_map->elements_kind(),
    269                                             receiver_map->elements_kind())) {
    270       return true;
    271     }
    272     return false;
    273   }
    274 
    275   CacheHolderFlag flag;
    276   Handle<Map> ic_holder_map(
    277       GetICCacheHolder(*receiver_type(), isolate(), &flag));
    278 
    279   DCHECK(flag != kCacheOnReceiver || receiver->IsJSObject());
    280   DCHECK(flag != kCacheOnPrototype || !receiver->IsJSReceiver());
    281   DCHECK(flag != kCacheOnPrototypeReceiverIsDictionary);
    282 
    283   if (state() == MONOMORPHIC) {
    284     int index = ic_holder_map->IndexInCodeCache(*name, *target());
    285     if (index >= 0) {
    286       ic_holder_map->RemoveFromCodeCache(*name, *target(), index);
    287     }
    288   }
    289 
    290   if (receiver->IsGlobalObject()) {
    291     Handle<GlobalObject> global = Handle<GlobalObject>::cast(receiver);
    292     LookupIterator it(global, name, LookupIterator::OWN_SKIP_INTERCEPTOR);
    293     if (it.state() == LookupIterator::ACCESS_CHECK) return false;
    294     if (!it.IsFound()) return false;
    295     Handle<PropertyCell> cell = it.GetPropertyCell();
    296     return cell->type()->IsConstant();
    297   }
    298 
    299   return true;
    300 }
    301 
    302 
    303 bool IC::IsNameCompatibleWithPrototypeFailure(Handle<Object> name) {
    304   if (target()->is_keyed_stub()) {
    305     // Determine whether the failure is due to a name failure.
    306     if (!name->IsName()) return false;
    307     Name* stub_name = target()->FindFirstName();
    308     if (*name != stub_name) return false;
    309   }
    310 
    311   return true;
    312 }
    313 
    314 
    315 void IC::UpdateState(Handle<Object> receiver, Handle<Object> name) {
    316   update_receiver_type(receiver);
    317   if (!name->IsString()) return;
    318   if (state() != MONOMORPHIC && state() != POLYMORPHIC) return;
    319   if (receiver->IsUndefined() || receiver->IsNull()) return;
    320 
    321   // Remove the target from the code cache if it became invalid
    322   // because of changes in the prototype chain to avoid hitting it
    323   // again.
    324   if (TryRemoveInvalidPrototypeDependentStub(receiver,
    325                                              Handle<String>::cast(name))) {
    326     MarkPrototypeFailure(name);
    327     return;
    328   }
    329 
    330   // The builtins object is special.  It only changes when JavaScript
    331   // builtins are loaded lazily.  It is important to keep inline
    332   // caches for the builtins object monomorphic.  Therefore, if we get
    333   // an inline cache miss for the builtins object after lazily loading
    334   // JavaScript builtins, we return uninitialized as the state to
    335   // force the inline cache back to monomorphic state.
    336   if (receiver->IsJSBuiltinsObject()) state_ = UNINITIALIZED;
    337 }
    338 
    339 
    340 MaybeHandle<Object> IC::TypeError(const char* type, Handle<Object> object,
    341                                   Handle<Object> key) {
    342   HandleScope scope(isolate());
    343   Handle<Object> args[2] = {key, object};
    344   THROW_NEW_ERROR(isolate(), NewTypeError(type, HandleVector(args, 2)), Object);
    345 }
    346 
    347 
    348 MaybeHandle<Object> IC::ReferenceError(const char* type, Handle<Name> name) {
    349   HandleScope scope(isolate());
    350   THROW_NEW_ERROR(isolate(), NewReferenceError(type, HandleVector(&name, 1)),
    351                   Object);
    352 }
    353 
    354 
    355 static void ComputeTypeInfoCountDelta(IC::State old_state, IC::State new_state,
    356                                       int* polymorphic_delta,
    357                                       int* generic_delta) {
    358   switch (old_state) {
    359     case UNINITIALIZED:
    360     case PREMONOMORPHIC:
    361       if (new_state == UNINITIALIZED || new_state == PREMONOMORPHIC) break;
    362       if (new_state == MONOMORPHIC || new_state == POLYMORPHIC) {
    363         *polymorphic_delta = 1;
    364       } else if (new_state == MEGAMORPHIC || new_state == GENERIC) {
    365         *generic_delta = 1;
    366       }
    367       break;
    368     case MONOMORPHIC:
    369     case POLYMORPHIC:
    370       if (new_state == MONOMORPHIC || new_state == POLYMORPHIC) break;
    371       *polymorphic_delta = -1;
    372       if (new_state == MEGAMORPHIC || new_state == GENERIC) {
    373         *generic_delta = 1;
    374       }
    375       break;
    376     case MEGAMORPHIC:
    377     case GENERIC:
    378       if (new_state == MEGAMORPHIC || new_state == GENERIC) break;
    379       *generic_delta = -1;
    380       if (new_state == MONOMORPHIC || new_state == POLYMORPHIC) {
    381         *polymorphic_delta = 1;
    382       }
    383       break;
    384     case PROTOTYPE_FAILURE:
    385     case DEBUG_STUB:
    386     case DEFAULT:
    387       UNREACHABLE();
    388   }
    389 }
    390 
    391 
    392 void IC::OnTypeFeedbackChanged(Isolate* isolate, Address address,
    393                                State old_state, State new_state,
    394                                bool target_remains_ic_stub) {
    395   Code* host =
    396       isolate->inner_pointer_to_code_cache()->GetCacheEntry(address)->code;
    397   if (host->kind() != Code::FUNCTION) return;
    398 
    399   if (FLAG_type_info_threshold > 0 && target_remains_ic_stub &&
    400       // Not all Code objects have TypeFeedbackInfo.
    401       host->type_feedback_info()->IsTypeFeedbackInfo()) {
    402     int polymorphic_delta = 0;  // "Polymorphic" here includes monomorphic.
    403     int generic_delta = 0;      // "Generic" here includes megamorphic.
    404     ComputeTypeInfoCountDelta(old_state, new_state, &polymorphic_delta,
    405                               &generic_delta);
    406     TypeFeedbackInfo* info = TypeFeedbackInfo::cast(host->type_feedback_info());
    407     info->change_ic_with_type_info_count(polymorphic_delta);
    408     info->change_ic_generic_count(generic_delta);
    409   }
    410   if (host->type_feedback_info()->IsTypeFeedbackInfo()) {
    411     TypeFeedbackInfo* info = TypeFeedbackInfo::cast(host->type_feedback_info());
    412     info->change_own_type_change_checksum();
    413   }
    414   host->set_profiler_ticks(0);
    415   isolate->runtime_profiler()->NotifyICChanged();
    416   // TODO(2029): When an optimized function is patched, it would
    417   // be nice to propagate the corresponding type information to its
    418   // unoptimized version for the benefit of later inlining.
    419 }
    420 
    421 
    422 void IC::PostPatching(Address address, Code* target, Code* old_target) {
    423   // Type vector based ICs update these statistics at a different time because
    424   // they don't always patch on state change.
    425   if (target->kind() == Code::CALL_IC) return;
    426 
    427   Isolate* isolate = target->GetHeap()->isolate();
    428   State old_state = UNINITIALIZED;
    429   State new_state = UNINITIALIZED;
    430   bool target_remains_ic_stub = false;
    431   if (old_target->is_inline_cache_stub() && target->is_inline_cache_stub()) {
    432     old_state = old_target->ic_state();
    433     new_state = target->ic_state();
    434     target_remains_ic_stub = true;
    435   }
    436 
    437   OnTypeFeedbackChanged(isolate, address, old_state, new_state,
    438                         target_remains_ic_stub);
    439 }
    440 
    441 
    442 void IC::RegisterWeakMapDependency(Handle<Code> stub) {
    443   if (FLAG_collect_maps && FLAG_weak_embedded_maps_in_ic &&
    444       stub->CanBeWeakStub()) {
    445     DCHECK(!stub->is_weak_stub());
    446     MapHandleList maps;
    447     stub->FindAllMaps(&maps);
    448     if (maps.length() == 1 && stub->IsWeakObjectInIC(*maps.at(0))) {
    449       Map::AddDependentIC(maps.at(0), stub);
    450       stub->mark_as_weak_stub();
    451       if (FLAG_enable_ool_constant_pool) {
    452         stub->constant_pool()->set_weak_object_state(
    453             ConstantPoolArray::WEAK_OBJECTS_IN_IC);
    454       }
    455     }
    456   }
    457 }
    458 
    459 
    460 void IC::InvalidateMaps(Code* stub) {
    461   DCHECK(stub->is_weak_stub());
    462   stub->mark_as_invalidated_weak_stub();
    463   Isolate* isolate = stub->GetIsolate();
    464   Heap* heap = isolate->heap();
    465   Object* undefined = heap->undefined_value();
    466   int mode_mask = RelocInfo::ModeMask(RelocInfo::EMBEDDED_OBJECT);
    467   for (RelocIterator it(stub, mode_mask); !it.done(); it.next()) {
    468     RelocInfo::Mode mode = it.rinfo()->rmode();
    469     if (mode == RelocInfo::EMBEDDED_OBJECT &&
    470         it.rinfo()->target_object()->IsMap()) {
    471       it.rinfo()->set_target_object(undefined, SKIP_WRITE_BARRIER);
    472     }
    473   }
    474   CpuFeatures::FlushICache(stub->instruction_start(), stub->instruction_size());
    475 }
    476 
    477 
    478 void IC::Clear(Isolate* isolate, Address address,
    479                ConstantPoolArray* constant_pool) {
    480   Code* target = GetTargetAtAddress(address, constant_pool);
    481 
    482   // Don't clear debug break inline cache as it will remove the break point.
    483   if (target->is_debug_stub()) return;
    484 
    485   switch (target->kind()) {
    486     case Code::LOAD_IC:
    487       return LoadIC::Clear(isolate, address, target, constant_pool);
    488     case Code::KEYED_LOAD_IC:
    489       return KeyedLoadIC::Clear(isolate, address, target, constant_pool);
    490     case Code::STORE_IC:
    491       return StoreIC::Clear(isolate, address, target, constant_pool);
    492     case Code::KEYED_STORE_IC:
    493       return KeyedStoreIC::Clear(isolate, address, target, constant_pool);
    494     case Code::CALL_IC:
    495       return CallIC::Clear(isolate, address, target, constant_pool);
    496     case Code::COMPARE_IC:
    497       return CompareIC::Clear(isolate, address, target, constant_pool);
    498     case Code::COMPARE_NIL_IC:
    499       return CompareNilIC::Clear(address, target, constant_pool);
    500     case Code::BINARY_OP_IC:
    501     case Code::TO_BOOLEAN_IC:
    502       // Clearing these is tricky and does not
    503       // make any performance difference.
    504       return;
    505     default:
    506       UNREACHABLE();
    507   }
    508 }
    509 
    510 
    511 void KeyedLoadIC::Clear(Isolate* isolate, Address address, Code* target,
    512                         ConstantPoolArray* constant_pool) {
    513   if (IsCleared(target)) return;
    514   // Make sure to also clear the map used in inline fast cases.  If we
    515   // do not clear these maps, cached code can keep objects alive
    516   // through the embedded maps.
    517   SetTargetAtAddress(address, *pre_monomorphic_stub(isolate), constant_pool);
    518 }
    519 
    520 
    521 void CallIC::Clear(Isolate* isolate, Address address, Code* target,
    522                    ConstantPoolArray* constant_pool) {
    523   // Currently, CallIC doesn't have state changes.
    524 }
    525 
    526 
    527 void LoadIC::Clear(Isolate* isolate, Address address, Code* target,
    528                    ConstantPoolArray* constant_pool) {
    529   if (IsCleared(target)) return;
    530   Code* code = PropertyICCompiler::FindPreMonomorphic(isolate, Code::LOAD_IC,
    531                                                       target->extra_ic_state());
    532   SetTargetAtAddress(address, code, constant_pool);
    533 }
    534 
    535 
    536 void StoreIC::Clear(Isolate* isolate, Address address, Code* target,
    537                     ConstantPoolArray* constant_pool) {
    538   if (IsCleared(target)) return;
    539   Code* code = PropertyICCompiler::FindPreMonomorphic(isolate, Code::STORE_IC,
    540                                                       target->extra_ic_state());
    541   SetTargetAtAddress(address, code, constant_pool);
    542 }
    543 
    544 
    545 void KeyedStoreIC::Clear(Isolate* isolate, Address address, Code* target,
    546                          ConstantPoolArray* constant_pool) {
    547   if (IsCleared(target)) return;
    548   SetTargetAtAddress(
    549       address, *pre_monomorphic_stub(
    550                    isolate, StoreIC::GetStrictMode(target->extra_ic_state())),
    551       constant_pool);
    552 }
    553 
    554 
    555 void CompareIC::Clear(Isolate* isolate, Address address, Code* target,
    556                       ConstantPoolArray* constant_pool) {
    557   DCHECK(CodeStub::GetMajorKey(target) == CodeStub::CompareIC);
    558   CompareICStub stub(target->stub_key(), isolate);
    559   // Only clear CompareICs that can retain objects.
    560   if (stub.state() != CompareICState::KNOWN_OBJECT) return;
    561   SetTargetAtAddress(address, GetRawUninitialized(isolate, stub.op()),
    562                      constant_pool);
    563   PatchInlinedSmiCode(address, DISABLE_INLINED_SMI_CHECK);
    564 }
    565 
    566 
    567 // static
    568 Handle<Code> KeyedLoadIC::generic_stub(Isolate* isolate) {
    569   if (FLAG_compiled_keyed_generic_loads) {
    570     return KeyedLoadGenericStub(isolate).GetCode();
    571   } else {
    572     return isolate->builtins()->KeyedLoadIC_Generic();
    573   }
    574 }
    575 
    576 
    577 static bool MigrateDeprecated(Handle<Object> object) {
    578   if (!object->IsJSObject()) return false;
    579   Handle<JSObject> receiver = Handle<JSObject>::cast(object);
    580   if (!receiver->map()->is_deprecated()) return false;
    581   JSObject::MigrateInstance(Handle<JSObject>::cast(object));
    582   return true;
    583 }
    584 
    585 
    586 MaybeHandle<Object> LoadIC::Load(Handle<Object> object, Handle<Name> name) {
    587   // If the object is undefined or null it's illegal to try to get any
    588   // of its properties; throw a TypeError in that case.
    589   if (object->IsUndefined() || object->IsNull()) {
    590     return TypeError("non_object_property_load", object, name);
    591   }
    592 
    593   // Check if the name is trivially convertible to an index and get
    594   // the element or char if so.
    595   uint32_t index;
    596   if (kind() == Code::KEYED_LOAD_IC && name->AsArrayIndex(&index)) {
    597     // Rewrite to the generic keyed load stub.
    598     if (FLAG_use_ic) {
    599       set_target(*KeyedLoadIC::generic_stub(isolate()));
    600       TRACE_IC("LoadIC", name);
    601       TRACE_GENERIC_IC(isolate(), "LoadIC", "name as array index");
    602     }
    603     Handle<Object> result;
    604     ASSIGN_RETURN_ON_EXCEPTION(
    605         isolate(), result,
    606         Runtime::GetElementOrCharAt(isolate(), object, index), Object);
    607     return result;
    608   }
    609 
    610   bool use_ic = MigrateDeprecated(object) ? false : FLAG_use_ic;
    611 
    612   // Named lookup in the object.
    613   LookupIterator it(object, name);
    614   LookupForRead(&it);
    615 
    616   if (it.IsFound() || !IsUndeclaredGlobal(object)) {
    617     // Update inline cache and stub cache.
    618     if (use_ic) UpdateCaches(&it);
    619 
    620     // Get the property.
    621     Handle<Object> result;
    622     ASSIGN_RETURN_ON_EXCEPTION(isolate(), result, Object::GetProperty(&it),
    623                                Object);
    624     if (it.IsFound()) {
    625       return result;
    626     } else if (!IsUndeclaredGlobal(object)) {
    627       LOG(isolate(), SuspectReadEvent(*name, *object));
    628       return result;
    629     }
    630   }
    631   return ReferenceError("not_defined", name);
    632 }
    633 
    634 
    635 static bool AddOneReceiverMapIfMissing(MapHandleList* receiver_maps,
    636                                        Handle<Map> new_receiver_map) {
    637   DCHECK(!new_receiver_map.is_null());
    638   for (int current = 0; current < receiver_maps->length(); ++current) {
    639     if (!receiver_maps->at(current).is_null() &&
    640         receiver_maps->at(current).is_identical_to(new_receiver_map)) {
    641       return false;
    642     }
    643   }
    644   receiver_maps->Add(new_receiver_map);
    645   return true;
    646 }
    647 
    648 
    649 bool IC::UpdatePolymorphicIC(Handle<Name> name, Handle<Code> code) {
    650   if (!code->is_handler()) return false;
    651   if (target()->is_keyed_stub() && state() != PROTOTYPE_FAILURE) return false;
    652   Handle<HeapType> type = receiver_type();
    653   TypeHandleList types;
    654   CodeHandleList handlers;
    655 
    656   TargetTypes(&types);
    657   int number_of_types = types.length();
    658   int deprecated_types = 0;
    659   int handler_to_overwrite = -1;
    660 
    661   for (int i = 0; i < number_of_types; i++) {
    662     Handle<HeapType> current_type = types.at(i);
    663     if (current_type->IsClass() &&
    664         current_type->AsClass()->Map()->is_deprecated()) {
    665       // Filter out deprecated maps to ensure their instances get migrated.
    666       ++deprecated_types;
    667     } else if (type->NowIs(current_type)) {
    668       // If the receiver type is already in the polymorphic IC, this indicates
    669       // there was a prototoype chain failure. In that case, just overwrite the
    670       // handler.
    671       handler_to_overwrite = i;
    672     } else if (handler_to_overwrite == -1 && current_type->IsClass() &&
    673                type->IsClass() &&
    674                IsTransitionOfMonomorphicTarget(*current_type->AsClass()->Map(),
    675                                                *type->AsClass()->Map())) {
    676       handler_to_overwrite = i;
    677     }
    678   }
    679 
    680   int number_of_valid_types =
    681       number_of_types - deprecated_types - (handler_to_overwrite != -1);
    682 
    683   if (number_of_valid_types >= 4) return false;
    684   if (number_of_types == 0) return false;
    685   if (!target()->FindHandlers(&handlers, types.length())) return false;
    686 
    687   number_of_valid_types++;
    688   if (number_of_valid_types > 1 && target()->is_keyed_stub()) return false;
    689   Handle<Code> ic;
    690   if (number_of_valid_types == 1) {
    691     ic = PropertyICCompiler::ComputeMonomorphic(kind(), name, type, code,
    692                                                 extra_ic_state());
    693   } else {
    694     if (handler_to_overwrite >= 0) {
    695       handlers.Set(handler_to_overwrite, code);
    696       if (!type->NowIs(types.at(handler_to_overwrite))) {
    697         types.Set(handler_to_overwrite, type);
    698       }
    699     } else {
    700       types.Add(type);
    701       handlers.Add(code);
    702     }
    703     ic = PropertyICCompiler::ComputePolymorphic(kind(), &types, &handlers,
    704                                                 number_of_valid_types, name,
    705                                                 extra_ic_state());
    706   }
    707   set_target(*ic);
    708   return true;
    709 }
    710 
    711 
    712 Handle<HeapType> IC::CurrentTypeOf(Handle<Object> object, Isolate* isolate) {
    713   return object->IsJSGlobalObject()
    714              ? HeapType::Constant(Handle<JSGlobalObject>::cast(object), isolate)
    715              : HeapType::NowOf(object, isolate);
    716 }
    717 
    718 
    719 Handle<Map> IC::TypeToMap(HeapType* type, Isolate* isolate) {
    720   if (type->Is(HeapType::Number()))
    721     return isolate->factory()->heap_number_map();
    722   if (type->Is(HeapType::Boolean())) return isolate->factory()->boolean_map();
    723   if (type->IsConstant()) {
    724     return handle(
    725         Handle<JSGlobalObject>::cast(type->AsConstant()->Value())->map());
    726   }
    727   DCHECK(type->IsClass());
    728   return type->AsClass()->Map();
    729 }
    730 
    731 
    732 template <class T>
    733 typename T::TypeHandle IC::MapToType(Handle<Map> map,
    734                                      typename T::Region* region) {
    735   if (map->instance_type() == HEAP_NUMBER_TYPE) {
    736     return T::Number(region);
    737   } else if (map->instance_type() == ODDBALL_TYPE) {
    738     // The only oddballs that can be recorded in ICs are booleans.
    739     return T::Boolean(region);
    740   } else {
    741     return T::Class(map, region);
    742   }
    743 }
    744 
    745 
    746 template Type* IC::MapToType<Type>(Handle<Map> map, Zone* zone);
    747 
    748 
    749 template Handle<HeapType> IC::MapToType<HeapType>(Handle<Map> map,
    750                                                   Isolate* region);
    751 
    752 
    753 void IC::UpdateMonomorphicIC(Handle<Code> handler, Handle<Name> name) {
    754   DCHECK(handler->is_handler());
    755   Handle<Code> ic = PropertyICCompiler::ComputeMonomorphic(
    756       kind(), name, receiver_type(), handler, extra_ic_state());
    757   set_target(*ic);
    758 }
    759 
    760 
    761 void IC::CopyICToMegamorphicCache(Handle<Name> name) {
    762   TypeHandleList types;
    763   CodeHandleList handlers;
    764   TargetTypes(&types);
    765   if (!target()->FindHandlers(&handlers, types.length())) return;
    766   for (int i = 0; i < types.length(); i++) {
    767     UpdateMegamorphicCache(*types.at(i), *name, *handlers.at(i));
    768   }
    769 }
    770 
    771 
    772 bool IC::IsTransitionOfMonomorphicTarget(Map* source_map, Map* target_map) {
    773   if (source_map == NULL) return true;
    774   if (target_map == NULL) return false;
    775   ElementsKind target_elements_kind = target_map->elements_kind();
    776   bool more_general_transition = IsMoreGeneralElementsKindTransition(
    777       source_map->elements_kind(), target_elements_kind);
    778   Map* transitioned_map =
    779       more_general_transition
    780           ? source_map->LookupElementsTransitionMap(target_elements_kind)
    781           : NULL;
    782 
    783   return transitioned_map == target_map;
    784 }
    785 
    786 
    787 void IC::PatchCache(Handle<Name> name, Handle<Code> code) {
    788   switch (state()) {
    789     case UNINITIALIZED:
    790     case PREMONOMORPHIC:
    791       UpdateMonomorphicIC(code, name);
    792       break;
    793     case PROTOTYPE_FAILURE:
    794     case MONOMORPHIC:
    795     case POLYMORPHIC:
    796       if (!target()->is_keyed_stub() || state() == PROTOTYPE_FAILURE) {
    797         if (UpdatePolymorphicIC(name, code)) break;
    798         CopyICToMegamorphicCache(name);
    799       }
    800       set_target(*megamorphic_stub());
    801     // Fall through.
    802     case MEGAMORPHIC:
    803       UpdateMegamorphicCache(*receiver_type(), *name, *code);
    804       break;
    805     case DEBUG_STUB:
    806       break;
    807     case DEFAULT:
    808     case GENERIC:
    809       UNREACHABLE();
    810       break;
    811   }
    812 }
    813 
    814 
    815 Handle<Code> LoadIC::initialize_stub(Isolate* isolate,
    816                                      ExtraICState extra_state) {
    817   return PropertyICCompiler::ComputeLoad(isolate, UNINITIALIZED, extra_state);
    818 }
    819 
    820 
    821 Handle<Code> LoadIC::megamorphic_stub() {
    822   if (kind() == Code::LOAD_IC) {
    823     MegamorphicLoadStub stub(isolate(), LoadICState(extra_ic_state()));
    824     return stub.GetCode();
    825   } else {
    826     DCHECK_EQ(Code::KEYED_LOAD_IC, kind());
    827     return KeyedLoadIC::generic_stub(isolate());
    828   }
    829 }
    830 
    831 
    832 Handle<Code> LoadIC::pre_monomorphic_stub(Isolate* isolate,
    833                                           ExtraICState extra_state) {
    834   return PropertyICCompiler::ComputeLoad(isolate, PREMONOMORPHIC, extra_state);
    835 }
    836 
    837 
    838 Handle<Code> KeyedLoadIC::pre_monomorphic_stub(Isolate* isolate) {
    839   return isolate->builtins()->KeyedLoadIC_PreMonomorphic();
    840 }
    841 
    842 
    843 Handle<Code> LoadIC::pre_monomorphic_stub() const {
    844   if (kind() == Code::LOAD_IC) {
    845     return LoadIC::pre_monomorphic_stub(isolate(), extra_ic_state());
    846   } else {
    847     DCHECK_EQ(Code::KEYED_LOAD_IC, kind());
    848     return KeyedLoadIC::pre_monomorphic_stub(isolate());
    849   }
    850 }
    851 
    852 
    853 Handle<Code> LoadIC::SimpleFieldLoad(FieldIndex index) {
    854   LoadFieldStub stub(isolate(), index);
    855   return stub.GetCode();
    856 }
    857 
    858 
    859 void LoadIC::UpdateCaches(LookupIterator* lookup) {
    860   if (state() == UNINITIALIZED) {
    861     // This is the first time we execute this inline cache. Set the target to
    862     // the pre monomorphic stub to delay setting the monomorphic state.
    863     set_target(*pre_monomorphic_stub());
    864     TRACE_IC("LoadIC", lookup->name());
    865     return;
    866   }
    867 
    868   Handle<Code> code;
    869   if (lookup->state() == LookupIterator::JSPROXY ||
    870       lookup->state() == LookupIterator::ACCESS_CHECK) {
    871     code = slow_stub();
    872   } else if (!lookup->IsFound()) {
    873     if (kind() == Code::LOAD_IC) {
    874       code = NamedLoadHandlerCompiler::ComputeLoadNonexistent(lookup->name(),
    875                                                               receiver_type());
    876       // TODO(jkummerow/verwaest): Introduce a builtin that handles this case.
    877       if (code.is_null()) code = slow_stub();
    878     } else {
    879       code = slow_stub();
    880     }
    881   } else {
    882     code = ComputeHandler(lookup);
    883   }
    884 
    885   PatchCache(lookup->name(), code);
    886   TRACE_IC("LoadIC", lookup->name());
    887 }
    888 
    889 
    890 void IC::UpdateMegamorphicCache(HeapType* type, Name* name, Code* code) {
    891   if (kind() == Code::KEYED_LOAD_IC || kind() == Code::KEYED_STORE_IC) return;
    892   Map* map = *TypeToMap(type, isolate());
    893   isolate()->stub_cache()->Set(name, map, code);
    894 }
    895 
    896 
    897 Handle<Code> IC::ComputeHandler(LookupIterator* lookup, Handle<Object> value) {
    898   bool receiver_is_holder =
    899       lookup->GetReceiver().is_identical_to(lookup->GetHolder<JSObject>());
    900   CacheHolderFlag flag;
    901   Handle<Map> stub_holder_map = IC::GetHandlerCacheHolder(
    902       *receiver_type(), receiver_is_holder, isolate(), &flag);
    903 
    904   Handle<Code> code = PropertyHandlerCompiler::Find(
    905       lookup->name(), stub_holder_map, kind(), flag,
    906       lookup->is_dictionary_holder() ? Code::NORMAL : Code::FAST);
    907   // Use the cached value if it exists, and if it is different from the
    908   // handler that just missed.
    909   if (!code.is_null()) {
    910     if (!maybe_handler_.is_null() &&
    911         !maybe_handler_.ToHandleChecked().is_identical_to(code)) {
    912       return code;
    913     }
    914     if (maybe_handler_.is_null()) {
    915       // maybe_handler_ is only populated for MONOMORPHIC and POLYMORPHIC ICs.
    916       // In MEGAMORPHIC case, check if the handler in the megamorphic stub
    917       // cache (which just missed) is different from the cached handler.
    918       if (state() == MEGAMORPHIC && lookup->GetReceiver()->IsHeapObject()) {
    919         Map* map = Handle<HeapObject>::cast(lookup->GetReceiver())->map();
    920         Code* megamorphic_cached_code =
    921             isolate()->stub_cache()->Get(*lookup->name(), map, code->flags());
    922         if (megamorphic_cached_code != *code) return code;
    923       } else {
    924         return code;
    925       }
    926     }
    927   }
    928 
    929   code = CompileHandler(lookup, value, flag);
    930   DCHECK(code->is_handler());
    931 
    932   // TODO(mvstanton): we'd only like to cache code on the map when it's custom
    933   // code compiled for this map, otherwise it's already cached in the global
    934   // code
    935   // cache. We are also guarding against installing code with flags that don't
    936   // match the desired CacheHolderFlag computed above, which would lead to
    937   // invalid lookups later.
    938   if (code->type() != Code::NORMAL &&
    939       Code::ExtractCacheHolderFromFlags(code->flags()) == flag) {
    940     Map::UpdateCodeCache(stub_holder_map, lookup->name(), code);
    941   }
    942 
    943   return code;
    944 }
    945 
    946 
    947 Handle<Code> LoadIC::CompileHandler(LookupIterator* lookup,
    948                                     Handle<Object> unused,
    949                                     CacheHolderFlag cache_holder) {
    950   Handle<Object> receiver = lookup->GetReceiver();
    951   if (receiver->IsString() &&
    952       Name::Equals(isolate()->factory()->length_string(), lookup->name())) {
    953     FieldIndex index = FieldIndex::ForInObjectOffset(String::kLengthOffset);
    954     return SimpleFieldLoad(index);
    955   }
    956 
    957   if (receiver->IsStringWrapper() &&
    958       Name::Equals(isolate()->factory()->length_string(), lookup->name())) {
    959     StringLengthStub string_length_stub(isolate());
    960     return string_length_stub.GetCode();
    961   }
    962 
    963   // Use specialized code for getting prototype of functions.
    964   if (receiver->IsJSFunction() &&
    965       Name::Equals(isolate()->factory()->prototype_string(), lookup->name()) &&
    966       Handle<JSFunction>::cast(receiver)->should_have_prototype() &&
    967       !Handle<JSFunction>::cast(receiver)
    968            ->map()
    969            ->has_non_instance_prototype()) {
    970     Handle<Code> stub;
    971     FunctionPrototypeStub function_prototype_stub(isolate());
    972     return function_prototype_stub.GetCode();
    973   }
    974 
    975   Handle<HeapType> type = receiver_type();
    976   Handle<JSObject> holder = lookup->GetHolder<JSObject>();
    977   bool receiver_is_holder = receiver.is_identical_to(holder);
    978   switch (lookup->state()) {
    979     case LookupIterator::INTERCEPTOR: {
    980       DCHECK(!holder->GetNamedInterceptor()->getter()->IsUndefined());
    981       NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
    982                                         cache_holder);
    983       // Perform a lookup behind the interceptor. Copy the LookupIterator since
    984       // the original iterator will be used to fetch the value.
    985       LookupIterator it = *lookup;
    986       it.Next();
    987       LookupForRead(&it);
    988       return compiler.CompileLoadInterceptor(&it);
    989     }
    990 
    991     case LookupIterator::ACCESSOR: {
    992       // Use simple field loads for some well-known callback properties.
    993       if (receiver_is_holder) {
    994         DCHECK(receiver->IsJSObject());
    995         Handle<JSObject> js_receiver = Handle<JSObject>::cast(receiver);
    996         int object_offset;
    997         if (Accessors::IsJSObjectFieldAccessor<HeapType>(type, lookup->name(),
    998                                                          &object_offset)) {
    999           FieldIndex index =
   1000               FieldIndex::ForInObjectOffset(object_offset, js_receiver->map());
   1001           return SimpleFieldLoad(index);
   1002         }
   1003       }
   1004 
   1005       Handle<Object> accessors = lookup->GetAccessors();
   1006       if (accessors->IsExecutableAccessorInfo()) {
   1007         Handle<ExecutableAccessorInfo> info =
   1008             Handle<ExecutableAccessorInfo>::cast(accessors);
   1009         if (v8::ToCData<Address>(info->getter()) == 0) break;
   1010         if (!ExecutableAccessorInfo::IsCompatibleReceiverType(isolate(), info,
   1011                                                               type)) {
   1012           break;
   1013         }
   1014         if (!holder->HasFastProperties()) break;
   1015         NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
   1016                                           cache_holder);
   1017         return compiler.CompileLoadCallback(lookup->name(), info);
   1018       }
   1019       if (accessors->IsAccessorPair()) {
   1020         Handle<Object> getter(Handle<AccessorPair>::cast(accessors)->getter(),
   1021                               isolate());
   1022         if (!getter->IsJSFunction()) break;
   1023         if (!holder->HasFastProperties()) break;
   1024         Handle<JSFunction> function = Handle<JSFunction>::cast(getter);
   1025         if (!receiver->IsJSObject() && !function->IsBuiltin() &&
   1026             function->shared()->strict_mode() == SLOPPY) {
   1027           // Calling sloppy non-builtins with a value as the receiver
   1028           // requires boxing.
   1029           break;
   1030         }
   1031         CallOptimization call_optimization(function);
   1032         NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
   1033                                           cache_holder);
   1034         if (call_optimization.is_simple_api_call() &&
   1035             call_optimization.IsCompatibleReceiver(receiver, holder)) {
   1036           return compiler.CompileLoadCallback(lookup->name(),
   1037                                               call_optimization);
   1038         }
   1039         return compiler.CompileLoadViaGetter(lookup->name(), function);
   1040       }
   1041       // TODO(dcarney): Handle correctly.
   1042       DCHECK(accessors->IsDeclaredAccessorInfo());
   1043       break;
   1044     }
   1045 
   1046     case LookupIterator::DATA: {
   1047       if (lookup->is_dictionary_holder()) {
   1048         if (kind() != Code::LOAD_IC) break;
   1049         if (holder->IsGlobalObject()) {
   1050           NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
   1051                                             cache_holder);
   1052           Handle<PropertyCell> cell = lookup->GetPropertyCell();
   1053           Handle<Code> code = compiler.CompileLoadGlobal(
   1054               cell, lookup->name(), lookup->IsConfigurable());
   1055           // TODO(verwaest): Move caching of these NORMAL stubs outside as well.
   1056           CacheHolderFlag flag;
   1057           Handle<Map> stub_holder_map = GetHandlerCacheHolder(
   1058               *type, receiver_is_holder, isolate(), &flag);
   1059           Map::UpdateCodeCache(stub_holder_map, lookup->name(), code);
   1060           return code;
   1061         }
   1062         // There is only one shared stub for loading normalized
   1063         // properties. It does not traverse the prototype chain, so the
   1064         // property must be found in the object for the stub to be
   1065         // applicable.
   1066         if (!receiver_is_holder) break;
   1067         return isolate()->builtins()->LoadIC_Normal();
   1068       }
   1069 
   1070       // -------------- Fields --------------
   1071       if (lookup->property_details().type() == FIELD) {
   1072         FieldIndex field = lookup->GetFieldIndex();
   1073         if (receiver_is_holder) {
   1074           return SimpleFieldLoad(field);
   1075         }
   1076         NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
   1077                                           cache_holder);
   1078         return compiler.CompileLoadField(lookup->name(), field);
   1079       }
   1080 
   1081       // -------------- Constant properties --------------
   1082       DCHECK(lookup->property_details().type() == CONSTANT);
   1083       if (receiver_is_holder) {
   1084         LoadConstantStub stub(isolate(), lookup->GetConstantIndex());
   1085         return stub.GetCode();
   1086       }
   1087       NamedLoadHandlerCompiler compiler(isolate(), receiver_type(), holder,
   1088                                         cache_holder);
   1089       return compiler.CompileLoadConstant(lookup->name(),
   1090                                           lookup->GetConstantIndex());
   1091     }
   1092 
   1093     case LookupIterator::ACCESS_CHECK:
   1094     case LookupIterator::JSPROXY:
   1095     case LookupIterator::NOT_FOUND:
   1096     case LookupIterator::TRANSITION:
   1097       UNREACHABLE();
   1098   }
   1099 
   1100   return slow_stub();
   1101 }
   1102 
   1103 
   1104 static Handle<Object> TryConvertKey(Handle<Object> key, Isolate* isolate) {
   1105   // This helper implements a few common fast cases for converting
   1106   // non-smi keys of keyed loads/stores to a smi or a string.
   1107   if (key->IsHeapNumber()) {
   1108     double value = Handle<HeapNumber>::cast(key)->value();
   1109     if (std::isnan(value)) {
   1110       key = isolate->factory()->nan_string();
   1111     } else {
   1112       int int_value = FastD2I(value);
   1113       if (value == int_value && Smi::IsValid(int_value)) {
   1114         key = Handle<Smi>(Smi::FromInt(int_value), isolate);
   1115       }
   1116     }
   1117   } else if (key->IsUndefined()) {
   1118     key = isolate->factory()->undefined_string();
   1119   }
   1120   return key;
   1121 }
   1122 
   1123 
   1124 Handle<Code> KeyedLoadIC::LoadElementStub(Handle<JSObject> receiver) {
   1125   Handle<Map> receiver_map(receiver->map(), isolate());
   1126   MapHandleList target_receiver_maps;
   1127   if (target().is_identical_to(string_stub())) {
   1128     target_receiver_maps.Add(isolate()->factory()->string_map());
   1129   } else {
   1130     TargetMaps(&target_receiver_maps);
   1131   }
   1132   if (target_receiver_maps.length() == 0) {
   1133     return PropertyICCompiler::ComputeKeyedLoadMonomorphic(receiver_map);
   1134   }
   1135 
   1136   // The first time a receiver is seen that is a transitioned version of the
   1137   // previous monomorphic receiver type, assume the new ElementsKind is the
   1138   // monomorphic type. This benefits global arrays that only transition
   1139   // once, and all call sites accessing them are faster if they remain
   1140   // monomorphic. If this optimistic assumption is not true, the IC will
   1141   // miss again and it will become polymorphic and support both the
   1142   // untransitioned and transitioned maps.
   1143   if (state() == MONOMORPHIC && IsMoreGeneralElementsKindTransition(
   1144                                     target_receiver_maps.at(0)->elements_kind(),
   1145                                     receiver->GetElementsKind())) {
   1146     return PropertyICCompiler::ComputeKeyedLoadMonomorphic(receiver_map);
   1147   }
   1148 
   1149   DCHECK(state() != GENERIC);
   1150 
   1151   // Determine the list of receiver maps that this call site has seen,
   1152   // adding the map that was just encountered.
   1153   if (!AddOneReceiverMapIfMissing(&target_receiver_maps, receiver_map)) {
   1154     // If the miss wasn't due to an unseen map, a polymorphic stub
   1155     // won't help, use the generic stub.
   1156     TRACE_GENERIC_IC(isolate(), "KeyedLoadIC", "same map added twice");
   1157     return generic_stub();
   1158   }
   1159 
   1160   // If the maximum number of receiver maps has been exceeded, use the generic
   1161   // version of the IC.
   1162   if (target_receiver_maps.length() > kMaxKeyedPolymorphism) {
   1163     TRACE_GENERIC_IC(isolate(), "KeyedLoadIC", "max polymorph exceeded");
   1164     return generic_stub();
   1165   }
   1166 
   1167   return PropertyICCompiler::ComputeKeyedLoadPolymorphic(&target_receiver_maps);
   1168 }
   1169 
   1170 
   1171 MaybeHandle<Object> KeyedLoadIC::Load(Handle<Object> object,
   1172                                       Handle<Object> key) {
   1173   if (MigrateDeprecated(object)) {
   1174     Handle<Object> result;
   1175     ASSIGN_RETURN_ON_EXCEPTION(
   1176         isolate(), result, Runtime::GetObjectProperty(isolate(), object, key),
   1177         Object);
   1178     return result;
   1179   }
   1180 
   1181   Handle<Object> load_handle;
   1182   Handle<Code> stub = generic_stub();
   1183 
   1184   // Check for non-string values that can be converted into an
   1185   // internalized string directly or is representable as a smi.
   1186   key = TryConvertKey(key, isolate());
   1187 
   1188   if (key->IsInternalizedString() || key->IsSymbol()) {
   1189     ASSIGN_RETURN_ON_EXCEPTION(isolate(), load_handle,
   1190                                LoadIC::Load(object, Handle<Name>::cast(key)),
   1191                                Object);
   1192   } else if (FLAG_use_ic && !object->IsAccessCheckNeeded()) {
   1193     if (object->IsString() && key->IsNumber()) {
   1194       if (state() == UNINITIALIZED) stub = string_stub();
   1195     } else if (object->IsJSObject()) {
   1196       Handle<JSObject> receiver = Handle<JSObject>::cast(object);
   1197       if (!Object::ToSmi(isolate(), key).is_null()) {
   1198         stub = LoadElementStub(receiver);
   1199       }
   1200     }
   1201   }
   1202 
   1203   if (!is_target_set()) {
   1204     Code* generic = *generic_stub();
   1205     if (*stub == generic) {
   1206       TRACE_GENERIC_IC(isolate(), "KeyedLoadIC", "set generic");
   1207     }
   1208     set_target(*stub);
   1209     TRACE_IC("LoadIC", key);
   1210   }
   1211 
   1212   if (!load_handle.is_null()) return load_handle;
   1213   Handle<Object> result;
   1214   ASSIGN_RETURN_ON_EXCEPTION(isolate(), result,
   1215                              Runtime::GetObjectProperty(isolate(), object, key),
   1216                              Object);
   1217   return result;
   1218 }
   1219 
   1220 
   1221 bool StoreIC::LookupForWrite(LookupIterator* it, Handle<Object> value,
   1222                              JSReceiver::StoreFromKeyed store_mode) {
   1223   // Disable ICs for non-JSObjects for now.
   1224   Handle<Object> receiver = it->GetReceiver();
   1225   if (!receiver->IsJSObject()) return false;
   1226   DCHECK(!Handle<JSObject>::cast(receiver)->map()->is_deprecated());
   1227 
   1228   for (; it->IsFound(); it->Next()) {
   1229     switch (it->state()) {
   1230       case LookupIterator::NOT_FOUND:
   1231       case LookupIterator::TRANSITION:
   1232         UNREACHABLE();
   1233       case LookupIterator::JSPROXY:
   1234         return false;
   1235       case LookupIterator::INTERCEPTOR: {
   1236         Handle<JSObject> holder = it->GetHolder<JSObject>();
   1237         InterceptorInfo* info = holder->GetNamedInterceptor();
   1238         if (it->HolderIsReceiverOrHiddenPrototype()) {
   1239           if (!info->setter()->IsUndefined()) return true;
   1240         } else if (!info->getter()->IsUndefined() ||
   1241                    !info->query()->IsUndefined()) {
   1242           return false;
   1243         }
   1244         break;
   1245       }
   1246       case LookupIterator::ACCESS_CHECK:
   1247         if (it->GetHolder<JSObject>()->IsAccessCheckNeeded()) return false;
   1248         break;
   1249       case LookupIterator::ACCESSOR:
   1250         return !it->IsReadOnly();
   1251       case LookupIterator::DATA: {
   1252         if (it->IsReadOnly()) return false;
   1253         Handle<JSObject> holder = it->GetHolder<JSObject>();
   1254         if (receiver.is_identical_to(holder)) {
   1255           it->PrepareForDataProperty(value);
   1256           // The previous receiver map might just have been deprecated,
   1257           // so reload it.
   1258           update_receiver_type(receiver);
   1259           return true;
   1260         }
   1261 
   1262         // Receiver != holder.
   1263         PrototypeIterator iter(it->isolate(), receiver);
   1264         if (receiver->IsJSGlobalProxy()) {
   1265           return it->GetHolder<Object>().is_identical_to(
   1266               PrototypeIterator::GetCurrent(iter));
   1267         }
   1268 
   1269         it->PrepareTransitionToDataProperty(value, NONE, store_mode);
   1270         return it->IsCacheableTransition();
   1271       }
   1272     }
   1273   }
   1274 
   1275   it->PrepareTransitionToDataProperty(value, NONE, store_mode);
   1276   return it->IsCacheableTransition();
   1277 }
   1278 
   1279 
   1280 MaybeHandle<Object> StoreIC::Store(Handle<Object> object, Handle<Name> name,
   1281                                    Handle<Object> value,
   1282                                    JSReceiver::StoreFromKeyed store_mode) {
   1283   // TODO(verwaest): Let SetProperty do the migration, since storing a property
   1284   // might deprecate the current map again, if value does not fit.
   1285   if (MigrateDeprecated(object) || object->IsJSProxy()) {
   1286     Handle<Object> result;
   1287     ASSIGN_RETURN_ON_EXCEPTION(
   1288         isolate(), result,
   1289         Object::SetProperty(object, name, value, strict_mode()), Object);
   1290     return result;
   1291   }
   1292 
   1293   // If the object is undefined or null it's illegal to try to set any
   1294   // properties on it; throw a TypeError in that case.
   1295   if (object->IsUndefined() || object->IsNull()) {
   1296     return TypeError("non_object_property_store", object, name);
   1297   }
   1298 
   1299   // Check if the given name is an array index.
   1300   uint32_t index;
   1301   if (name->AsArrayIndex(&index)) {
   1302     // Ignore other stores where the receiver is not a JSObject.
   1303     // TODO(1475): Must check prototype chains of object wrappers.
   1304     if (!object->IsJSObject()) return value;
   1305     Handle<JSObject> receiver = Handle<JSObject>::cast(object);
   1306 
   1307     Handle<Object> result;
   1308     ASSIGN_RETURN_ON_EXCEPTION(
   1309         isolate(), result,
   1310         JSObject::SetElement(receiver, index, value, NONE, strict_mode()),
   1311         Object);
   1312     return value;
   1313   }
   1314 
   1315   // Observed objects are always modified through the runtime.
   1316   if (object->IsHeapObject() &&
   1317       Handle<HeapObject>::cast(object)->map()->is_observed()) {
   1318     Handle<Object> result;
   1319     ASSIGN_RETURN_ON_EXCEPTION(
   1320         isolate(), result,
   1321         Object::SetProperty(object, name, value, strict_mode(), store_mode),
   1322         Object);
   1323     return result;
   1324   }
   1325 
   1326   LookupIterator it(object, name);
   1327   if (FLAG_use_ic) UpdateCaches(&it, value, store_mode);
   1328 
   1329   // Set the property.
   1330   Handle<Object> result;
   1331   ASSIGN_RETURN_ON_EXCEPTION(
   1332       isolate(), result,
   1333       Object::SetProperty(&it, value, strict_mode(), store_mode), Object);
   1334   return result;
   1335 }
   1336 
   1337 
   1338 Handle<Code> CallIC::initialize_stub(Isolate* isolate, int argc,
   1339                                      CallICState::CallType call_type) {
   1340   CallICStub stub(isolate, CallICState(argc, call_type));
   1341   Handle<Code> code = stub.GetCode();
   1342   return code;
   1343 }
   1344 
   1345 
   1346 Handle<Code> StoreIC::initialize_stub(Isolate* isolate,
   1347                                       StrictMode strict_mode) {
   1348   ExtraICState extra_state = ComputeExtraICState(strict_mode);
   1349   Handle<Code> ic =
   1350       PropertyICCompiler::ComputeStore(isolate, UNINITIALIZED, extra_state);
   1351   return ic;
   1352 }
   1353 
   1354 
   1355 Handle<Code> StoreIC::megamorphic_stub() {
   1356   if (kind() == Code::STORE_IC) {
   1357     return PropertyICCompiler::ComputeStore(isolate(), MEGAMORPHIC,
   1358                                             extra_ic_state());
   1359   } else {
   1360     DCHECK(kind() == Code::KEYED_STORE_IC);
   1361     if (strict_mode() == STRICT) {
   1362       return isolate()->builtins()->KeyedStoreIC_Generic_Strict();
   1363     } else {
   1364       return isolate()->builtins()->KeyedStoreIC_Generic();
   1365     }
   1366   }
   1367 }
   1368 
   1369 
   1370 Handle<Code> StoreIC::generic_stub() const {
   1371   if (kind() == Code::STORE_IC) {
   1372     return PropertyICCompiler::ComputeStore(isolate(), GENERIC,
   1373                                             extra_ic_state());
   1374   } else {
   1375     DCHECK(kind() == Code::KEYED_STORE_IC);
   1376     if (strict_mode() == STRICT) {
   1377       return isolate()->builtins()->KeyedStoreIC_Generic_Strict();
   1378     } else {
   1379       return isolate()->builtins()->KeyedStoreIC_Generic();
   1380     }
   1381   }
   1382 }
   1383 
   1384 
   1385 Handle<Code> StoreIC::slow_stub() const {
   1386   if (kind() == Code::STORE_IC) {
   1387     return isolate()->builtins()->StoreIC_Slow();
   1388   } else {
   1389     DCHECK(kind() == Code::KEYED_STORE_IC);
   1390     return isolate()->builtins()->KeyedStoreIC_Slow();
   1391   }
   1392 }
   1393 
   1394 
   1395 Handle<Code> StoreIC::pre_monomorphic_stub(Isolate* isolate,
   1396                                            StrictMode strict_mode) {
   1397   ExtraICState state = ComputeExtraICState(strict_mode);
   1398   return PropertyICCompiler::ComputeStore(isolate, PREMONOMORPHIC, state);
   1399 }
   1400 
   1401 
   1402 void StoreIC::UpdateCaches(LookupIterator* lookup, Handle<Object> value,
   1403                            JSReceiver::StoreFromKeyed store_mode) {
   1404   if (state() == UNINITIALIZED) {
   1405     // This is the first time we execute this inline cache. Set the target to
   1406     // the pre monomorphic stub to delay setting the monomorphic state.
   1407     set_target(*pre_monomorphic_stub());
   1408     TRACE_IC("StoreIC", lookup->name());
   1409     return;
   1410   }
   1411 
   1412   bool use_ic = LookupForWrite(lookup, value, store_mode);
   1413   if (!use_ic) {
   1414     TRACE_GENERIC_IC(isolate(), "StoreIC", "LookupForWrite said 'false'");
   1415   }
   1416   Handle<Code> code = use_ic ? ComputeHandler(lookup, value) : slow_stub();
   1417 
   1418   PatchCache(lookup->name(), code);
   1419   TRACE_IC("StoreIC", lookup->name());
   1420 }
   1421 
   1422 
   1423 Handle<Code> StoreIC::CompileHandler(LookupIterator* lookup,
   1424                                      Handle<Object> value,
   1425                                      CacheHolderFlag cache_holder) {
   1426   DCHECK_NE(LookupIterator::JSPROXY, lookup->state());
   1427 
   1428   // This is currently guaranteed by checks in StoreIC::Store.
   1429   Handle<JSObject> receiver = Handle<JSObject>::cast(lookup->GetReceiver());
   1430   Handle<JSObject> holder = lookup->GetHolder<JSObject>();
   1431   DCHECK(!receiver->IsAccessCheckNeeded());
   1432 
   1433   switch (lookup->state()) {
   1434     case LookupIterator::TRANSITION: {
   1435       Handle<Map> transition = lookup->transition_map();
   1436       // Currently not handled by CompileStoreTransition.
   1437       if (!holder->HasFastProperties()) {
   1438         TRACE_GENERIC_IC(isolate(), "StoreIC", "transition from slow");
   1439         break;
   1440       }
   1441 
   1442       DCHECK(lookup->IsCacheableTransition());
   1443       NamedStoreHandlerCompiler compiler(isolate(), receiver_type(), holder);
   1444       return compiler.CompileStoreTransition(transition, lookup->name());
   1445     }
   1446 
   1447     case LookupIterator::INTERCEPTOR: {
   1448       DCHECK(!holder->GetNamedInterceptor()->setter()->IsUndefined());
   1449       NamedStoreHandlerCompiler compiler(isolate(), receiver_type(), holder);
   1450       return compiler.CompileStoreInterceptor(lookup->name());
   1451     }
   1452 
   1453     case LookupIterator::ACCESSOR: {
   1454       if (!holder->HasFastProperties()) {
   1455         TRACE_GENERIC_IC(isolate(), "StoreIC", "accessor on slow map");
   1456         break;
   1457       }
   1458       Handle<Object> accessors = lookup->GetAccessors();
   1459       if (accessors->IsExecutableAccessorInfo()) {
   1460         Handle<ExecutableAccessorInfo> info =
   1461             Handle<ExecutableAccessorInfo>::cast(accessors);
   1462         if (v8::ToCData<Address>(info->setter()) == 0) {
   1463           TRACE_GENERIC_IC(isolate(), "StoreIC", "setter == 0");
   1464           break;
   1465         }
   1466         if (!ExecutableAccessorInfo::IsCompatibleReceiverType(
   1467                 isolate(), info, receiver_type())) {
   1468           TRACE_GENERIC_IC(isolate(), "StoreIC", "incompatible receiver type");
   1469           break;
   1470         }
   1471         NamedStoreHandlerCompiler compiler(isolate(), receiver_type(), holder);
   1472         return compiler.CompileStoreCallback(receiver, lookup->name(), info);
   1473       } else if (accessors->IsAccessorPair()) {
   1474         Handle<Object> setter(Handle<AccessorPair>::cast(accessors)->setter(),
   1475                               isolate());
   1476         if (!setter->IsJSFunction()) {
   1477           TRACE_GENERIC_IC(isolate(), "StoreIC", "setter not a function");
   1478           break;
   1479         }
   1480         Handle<JSFunction> function = Handle<JSFunction>::cast(setter);
   1481         CallOptimization call_optimization(function);
   1482         NamedStoreHandlerCompiler compiler(isolate(), receiver_type(), holder);
   1483         if (call_optimization.is_simple_api_call() &&
   1484             call_optimization.IsCompatibleReceiver(receiver, holder)) {
   1485           return compiler.CompileStoreCallback(receiver, lookup->name(),
   1486                                                call_optimization);
   1487         }
   1488         return compiler.CompileStoreViaSetter(receiver, lookup->name(),
   1489                                               Handle<JSFunction>::cast(setter));
   1490       }
   1491       // TODO(dcarney): Handle correctly.
   1492       DCHECK(accessors->IsDeclaredAccessorInfo());
   1493       TRACE_GENERIC_IC(isolate(), "StoreIC", "declared accessor info");
   1494       break;
   1495     }
   1496 
   1497     case LookupIterator::DATA: {
   1498       if (lookup->is_dictionary_holder()) {
   1499         if (holder->IsGlobalObject()) {
   1500           Handle<PropertyCell> cell = lookup->GetPropertyCell();
   1501           Handle<HeapType> union_type = PropertyCell::UpdatedType(cell, value);
   1502           StoreGlobalStub stub(isolate(), union_type->IsConstant(),
   1503                                receiver->IsJSGlobalProxy());
   1504           Handle<Code> code = stub.GetCodeCopyFromTemplate(
   1505               Handle<GlobalObject>::cast(holder), cell);
   1506           // TODO(verwaest): Move caching of these NORMAL stubs outside as well.
   1507           HeapObject::UpdateMapCodeCache(receiver, lookup->name(), code);
   1508           return code;
   1509         }
   1510         DCHECK(holder.is_identical_to(receiver));
   1511         return isolate()->builtins()->StoreIC_Normal();
   1512       }
   1513 
   1514       // -------------- Fields --------------
   1515       if (lookup->property_details().type() == FIELD) {
   1516         bool use_stub = true;
   1517         if (lookup->representation().IsHeapObject()) {
   1518           // Only use a generic stub if no types need to be tracked.
   1519           Handle<HeapType> field_type = lookup->GetFieldType();
   1520           HeapType::Iterator<Map> it = field_type->Classes();
   1521           use_stub = it.Done();
   1522         }
   1523         if (use_stub) {
   1524           StoreFieldStub stub(isolate(), lookup->GetFieldIndex(),
   1525                               lookup->representation());
   1526           return stub.GetCode();
   1527         }
   1528         NamedStoreHandlerCompiler compiler(isolate(), receiver_type(), holder);
   1529         return compiler.CompileStoreField(lookup);
   1530       }
   1531 
   1532       // -------------- Constant properties --------------
   1533       DCHECK(lookup->property_details().type() == CONSTANT);
   1534       TRACE_GENERIC_IC(isolate(), "StoreIC", "constant property");
   1535       break;
   1536     }
   1537 
   1538     case LookupIterator::ACCESS_CHECK:
   1539     case LookupIterator::JSPROXY:
   1540     case LookupIterator::NOT_FOUND:
   1541       UNREACHABLE();
   1542   }
   1543   return slow_stub();
   1544 }
   1545 
   1546 
   1547 Handle<Code> KeyedStoreIC::StoreElementStub(Handle<JSObject> receiver,
   1548                                             KeyedAccessStoreMode store_mode) {
   1549   // Don't handle megamorphic property accesses for INTERCEPTORS or CALLBACKS
   1550   // via megamorphic stubs, since they don't have a map in their relocation info
   1551   // and so the stubs can't be harvested for the object needed for a map check.
   1552   if (target()->type() != Code::NORMAL) {
   1553     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-NORMAL target type");
   1554     return generic_stub();
   1555   }
   1556 
   1557   Handle<Map> receiver_map(receiver->map(), isolate());
   1558   MapHandleList target_receiver_maps;
   1559   TargetMaps(&target_receiver_maps);
   1560   if (target_receiver_maps.length() == 0) {
   1561     Handle<Map> monomorphic_map =
   1562         ComputeTransitionedMap(receiver_map, store_mode);
   1563     store_mode = GetNonTransitioningStoreMode(store_mode);
   1564     return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
   1565         monomorphic_map, strict_mode(), store_mode);
   1566   }
   1567 
   1568   // There are several special cases where an IC that is MONOMORPHIC can still
   1569   // transition to a different GetNonTransitioningStoreMode IC that handles a
   1570   // superset of the original IC. Handle those here if the receiver map hasn't
   1571   // changed or it has transitioned to a more general kind.
   1572   KeyedAccessStoreMode old_store_mode =
   1573       KeyedStoreIC::GetKeyedAccessStoreMode(target()->extra_ic_state());
   1574   Handle<Map> previous_receiver_map = target_receiver_maps.at(0);
   1575   if (state() == MONOMORPHIC) {
   1576     Handle<Map> transitioned_receiver_map = receiver_map;
   1577     if (IsTransitionStoreMode(store_mode)) {
   1578       transitioned_receiver_map =
   1579           ComputeTransitionedMap(receiver_map, store_mode);
   1580     }
   1581     if ((receiver_map.is_identical_to(previous_receiver_map) &&
   1582          IsTransitionStoreMode(store_mode)) ||
   1583         IsTransitionOfMonomorphicTarget(*previous_receiver_map,
   1584                                         *transitioned_receiver_map)) {
   1585       // If the "old" and "new" maps are in the same elements map family, or
   1586       // if they at least come from the same origin for a transitioning store,
   1587       // stay MONOMORPHIC and use the map for the most generic ElementsKind.
   1588       store_mode = GetNonTransitioningStoreMode(store_mode);
   1589       return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
   1590           transitioned_receiver_map, strict_mode(), store_mode);
   1591     } else if (*previous_receiver_map == receiver->map() &&
   1592                old_store_mode == STANDARD_STORE &&
   1593                (store_mode == STORE_AND_GROW_NO_TRANSITION ||
   1594                 store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS ||
   1595                 store_mode == STORE_NO_TRANSITION_HANDLE_COW)) {
   1596       // A "normal" IC that handles stores can switch to a version that can
   1597       // grow at the end of the array, handle OOB accesses or copy COW arrays
   1598       // and still stay MONOMORPHIC.
   1599       return PropertyICCompiler::ComputeKeyedStoreMonomorphic(
   1600           receiver_map, strict_mode(), store_mode);
   1601     }
   1602   }
   1603 
   1604   DCHECK(state() != GENERIC);
   1605 
   1606   bool map_added =
   1607       AddOneReceiverMapIfMissing(&target_receiver_maps, receiver_map);
   1608 
   1609   if (IsTransitionStoreMode(store_mode)) {
   1610     Handle<Map> transitioned_receiver_map =
   1611         ComputeTransitionedMap(receiver_map, store_mode);
   1612     map_added |= AddOneReceiverMapIfMissing(&target_receiver_maps,
   1613                                             transitioned_receiver_map);
   1614   }
   1615 
   1616   if (!map_added) {
   1617     // If the miss wasn't due to an unseen map, a polymorphic stub
   1618     // won't help, use the generic stub.
   1619     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "same map added twice");
   1620     return generic_stub();
   1621   }
   1622 
   1623   // If the maximum number of receiver maps has been exceeded, use the generic
   1624   // version of the IC.
   1625   if (target_receiver_maps.length() > kMaxKeyedPolymorphism) {
   1626     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "max polymorph exceeded");
   1627     return generic_stub();
   1628   }
   1629 
   1630   // Make sure all polymorphic handlers have the same store mode, otherwise the
   1631   // generic stub must be used.
   1632   store_mode = GetNonTransitioningStoreMode(store_mode);
   1633   if (old_store_mode != STANDARD_STORE) {
   1634     if (store_mode == STANDARD_STORE) {
   1635       store_mode = old_store_mode;
   1636     } else if (store_mode != old_store_mode) {
   1637       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "store mode mismatch");
   1638       return generic_stub();
   1639     }
   1640   }
   1641 
   1642   // If the store mode isn't the standard mode, make sure that all polymorphic
   1643   // receivers are either external arrays, or all "normal" arrays. Otherwise,
   1644   // use the generic stub.
   1645   if (store_mode != STANDARD_STORE) {
   1646     int external_arrays = 0;
   1647     for (int i = 0; i < target_receiver_maps.length(); ++i) {
   1648       if (target_receiver_maps[i]->has_external_array_elements() ||
   1649           target_receiver_maps[i]->has_fixed_typed_array_elements()) {
   1650         external_arrays++;
   1651       }
   1652     }
   1653     if (external_arrays != 0 &&
   1654         external_arrays != target_receiver_maps.length()) {
   1655       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC",
   1656                        "unsupported combination of external and normal arrays");
   1657       return generic_stub();
   1658     }
   1659   }
   1660 
   1661   return PropertyICCompiler::ComputeKeyedStorePolymorphic(
   1662       &target_receiver_maps, store_mode, strict_mode());
   1663 }
   1664 
   1665 
   1666 Handle<Map> KeyedStoreIC::ComputeTransitionedMap(
   1667     Handle<Map> map, KeyedAccessStoreMode store_mode) {
   1668   switch (store_mode) {
   1669     case STORE_TRANSITION_SMI_TO_OBJECT:
   1670     case STORE_TRANSITION_DOUBLE_TO_OBJECT:
   1671     case STORE_AND_GROW_TRANSITION_SMI_TO_OBJECT:
   1672     case STORE_AND_GROW_TRANSITION_DOUBLE_TO_OBJECT:
   1673       return Map::TransitionElementsTo(map, FAST_ELEMENTS);
   1674     case STORE_TRANSITION_SMI_TO_DOUBLE:
   1675     case STORE_AND_GROW_TRANSITION_SMI_TO_DOUBLE:
   1676       return Map::TransitionElementsTo(map, FAST_DOUBLE_ELEMENTS);
   1677     case STORE_TRANSITION_HOLEY_SMI_TO_OBJECT:
   1678     case STORE_TRANSITION_HOLEY_DOUBLE_TO_OBJECT:
   1679     case STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_OBJECT:
   1680     case STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT:
   1681       return Map::TransitionElementsTo(map, FAST_HOLEY_ELEMENTS);
   1682     case STORE_TRANSITION_HOLEY_SMI_TO_DOUBLE:
   1683     case STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_DOUBLE:
   1684       return Map::TransitionElementsTo(map, FAST_HOLEY_DOUBLE_ELEMENTS);
   1685     case STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS:
   1686       DCHECK(map->has_external_array_elements());
   1687     // Fall through
   1688     case STORE_NO_TRANSITION_HANDLE_COW:
   1689     case STANDARD_STORE:
   1690     case STORE_AND_GROW_NO_TRANSITION:
   1691       return map;
   1692   }
   1693   UNREACHABLE();
   1694   return MaybeHandle<Map>().ToHandleChecked();
   1695 }
   1696 
   1697 
   1698 bool IsOutOfBoundsAccess(Handle<JSObject> receiver, int index) {
   1699   if (receiver->IsJSArray()) {
   1700     return JSArray::cast(*receiver)->length()->IsSmi() &&
   1701            index >= Smi::cast(JSArray::cast(*receiver)->length())->value();
   1702   }
   1703   return index >= receiver->elements()->length();
   1704 }
   1705 
   1706 
   1707 KeyedAccessStoreMode KeyedStoreIC::GetStoreMode(Handle<JSObject> receiver,
   1708                                                 Handle<Object> key,
   1709                                                 Handle<Object> value) {
   1710   Handle<Smi> smi_key = Object::ToSmi(isolate(), key).ToHandleChecked();
   1711   int index = smi_key->value();
   1712   bool oob_access = IsOutOfBoundsAccess(receiver, index);
   1713   // Don't consider this a growing store if the store would send the receiver to
   1714   // dictionary mode.
   1715   bool allow_growth = receiver->IsJSArray() && oob_access &&
   1716                       !receiver->WouldConvertToSlowElements(key);
   1717   if (allow_growth) {
   1718     // Handle growing array in stub if necessary.
   1719     if (receiver->HasFastSmiElements()) {
   1720       if (value->IsHeapNumber()) {
   1721         if (receiver->HasFastHoleyElements()) {
   1722           return STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_DOUBLE;
   1723         } else {
   1724           return STORE_AND_GROW_TRANSITION_SMI_TO_DOUBLE;
   1725         }
   1726       }
   1727       if (value->IsHeapObject()) {
   1728         if (receiver->HasFastHoleyElements()) {
   1729           return STORE_AND_GROW_TRANSITION_HOLEY_SMI_TO_OBJECT;
   1730         } else {
   1731           return STORE_AND_GROW_TRANSITION_SMI_TO_OBJECT;
   1732         }
   1733       }
   1734     } else if (receiver->HasFastDoubleElements()) {
   1735       if (!value->IsSmi() && !value->IsHeapNumber()) {
   1736         if (receiver->HasFastHoleyElements()) {
   1737           return STORE_AND_GROW_TRANSITION_HOLEY_DOUBLE_TO_OBJECT;
   1738         } else {
   1739           return STORE_AND_GROW_TRANSITION_DOUBLE_TO_OBJECT;
   1740         }
   1741       }
   1742     }
   1743     return STORE_AND_GROW_NO_TRANSITION;
   1744   } else {
   1745     // Handle only in-bounds elements accesses.
   1746     if (receiver->HasFastSmiElements()) {
   1747       if (value->IsHeapNumber()) {
   1748         if (receiver->HasFastHoleyElements()) {
   1749           return STORE_TRANSITION_HOLEY_SMI_TO_DOUBLE;
   1750         } else {
   1751           return STORE_TRANSITION_SMI_TO_DOUBLE;
   1752         }
   1753       } else if (value->IsHeapObject()) {
   1754         if (receiver->HasFastHoleyElements()) {
   1755           return STORE_TRANSITION_HOLEY_SMI_TO_OBJECT;
   1756         } else {
   1757           return STORE_TRANSITION_SMI_TO_OBJECT;
   1758         }
   1759       }
   1760     } else if (receiver->HasFastDoubleElements()) {
   1761       if (!value->IsSmi() && !value->IsHeapNumber()) {
   1762         if (receiver->HasFastHoleyElements()) {
   1763           return STORE_TRANSITION_HOLEY_DOUBLE_TO_OBJECT;
   1764         } else {
   1765           return STORE_TRANSITION_DOUBLE_TO_OBJECT;
   1766         }
   1767       }
   1768     }
   1769     if (!FLAG_trace_external_array_abuse &&
   1770         receiver->map()->has_external_array_elements() && oob_access) {
   1771       return STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS;
   1772     }
   1773     Heap* heap = receiver->GetHeap();
   1774     if (receiver->elements()->map() == heap->fixed_cow_array_map()) {
   1775       return STORE_NO_TRANSITION_HANDLE_COW;
   1776     } else {
   1777       return STANDARD_STORE;
   1778     }
   1779   }
   1780 }
   1781 
   1782 
   1783 MaybeHandle<Object> KeyedStoreIC::Store(Handle<Object> object,
   1784                                         Handle<Object> key,
   1785                                         Handle<Object> value) {
   1786   // TODO(verwaest): Let SetProperty do the migration, since storing a property
   1787   // might deprecate the current map again, if value does not fit.
   1788   if (MigrateDeprecated(object)) {
   1789     Handle<Object> result;
   1790     ASSIGN_RETURN_ON_EXCEPTION(
   1791         isolate(), result, Runtime::SetObjectProperty(isolate(), object, key,
   1792                                                       value, strict_mode()),
   1793         Object);
   1794     return result;
   1795   }
   1796 
   1797   // Check for non-string values that can be converted into an
   1798   // internalized string directly or is representable as a smi.
   1799   key = TryConvertKey(key, isolate());
   1800 
   1801   Handle<Object> store_handle;
   1802   Handle<Code> stub = generic_stub();
   1803 
   1804   if (key->IsInternalizedString()) {
   1805     ASSIGN_RETURN_ON_EXCEPTION(
   1806         isolate(), store_handle,
   1807         StoreIC::Store(object, Handle<String>::cast(key), value,
   1808                        JSReceiver::MAY_BE_STORE_FROM_KEYED),
   1809         Object);
   1810     // TODO(jkummerow): Ideally we'd wrap this in "if (!is_target_set())",
   1811     // but doing so causes Hydrogen crashes. Needs investigation.
   1812     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC",
   1813                      "unhandled internalized string key");
   1814     TRACE_IC("StoreIC", key);
   1815     set_target(*stub);
   1816     return store_handle;
   1817   }
   1818 
   1819   bool use_ic =
   1820       FLAG_use_ic && !object->IsStringWrapper() &&
   1821       !object->IsAccessCheckNeeded() && !object->IsJSGlobalProxy() &&
   1822       !(object->IsJSObject() && JSObject::cast(*object)->map()->is_observed());
   1823   if (use_ic && !object->IsSmi()) {
   1824     // Don't use ICs for maps of the objects in Array's prototype chain. We
   1825     // expect to be able to trap element sets to objects with those maps in
   1826     // the runtime to enable optimization of element hole access.
   1827     Handle<HeapObject> heap_object = Handle<HeapObject>::cast(object);
   1828     if (heap_object->map()->IsMapInArrayPrototypeChain()) {
   1829       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "map in array prototype");
   1830       use_ic = false;
   1831     }
   1832   }
   1833 
   1834   if (use_ic) {
   1835     DCHECK(!object->IsAccessCheckNeeded());
   1836 
   1837     if (object->IsJSObject()) {
   1838       Handle<JSObject> receiver = Handle<JSObject>::cast(object);
   1839       bool key_is_smi_like = !Object::ToSmi(isolate(), key).is_null();
   1840       if (receiver->elements()->map() ==
   1841           isolate()->heap()->sloppy_arguments_elements_map()) {
   1842         if (strict_mode() == SLOPPY) {
   1843           stub = sloppy_arguments_stub();
   1844         } else {
   1845           TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "arguments receiver");
   1846         }
   1847       } else if (key_is_smi_like &&
   1848                  !(target().is_identical_to(sloppy_arguments_stub()))) {
   1849         // We should go generic if receiver isn't a dictionary, but our
   1850         // prototype chain does have dictionary elements. This ensures that
   1851         // other non-dictionary receivers in the polymorphic case benefit
   1852         // from fast path keyed stores.
   1853         if (!(receiver->map()->DictionaryElementsInPrototypeChainOnly())) {
   1854           KeyedAccessStoreMode store_mode = GetStoreMode(receiver, key, value);
   1855           stub = StoreElementStub(receiver, store_mode);
   1856         } else {
   1857           TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "dictionary prototype");
   1858         }
   1859       } else {
   1860         TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-smi-like key");
   1861       }
   1862     } else {
   1863       TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "non-JSObject receiver");
   1864     }
   1865   }
   1866 
   1867   if (store_handle.is_null()) {
   1868     ASSIGN_RETURN_ON_EXCEPTION(
   1869         isolate(), store_handle,
   1870         Runtime::SetObjectProperty(isolate(), object, key, value,
   1871                                    strict_mode()),
   1872         Object);
   1873   }
   1874 
   1875   DCHECK(!is_target_set());
   1876   Code* generic = *generic_stub();
   1877   if (*stub == generic) {
   1878     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "set generic");
   1879   }
   1880   if (*stub == *slow_stub()) {
   1881     TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "slow stub");
   1882   }
   1883   DCHECK(!stub.is_null());
   1884   set_target(*stub);
   1885   TRACE_IC("StoreIC", key);
   1886 
   1887   return store_handle;
   1888 }
   1889 
   1890 
   1891 bool CallIC::DoCustomHandler(Handle<Object> receiver, Handle<Object> function,
   1892                              Handle<TypeFeedbackVector> vector,
   1893                              Handle<Smi> slot, const CallICState& state) {
   1894   DCHECK(FLAG_use_ic && function->IsJSFunction());
   1895 
   1896   // Are we the array function?
   1897   Handle<JSFunction> array_function =
   1898       Handle<JSFunction>(isolate()->native_context()->array_function());
   1899   if (array_function.is_identical_to(Handle<JSFunction>::cast(function))) {
   1900     // Alter the slot.
   1901     IC::State old_state = FeedbackToState(vector, slot);
   1902     Object* feedback = vector->get(slot->value());
   1903     if (!feedback->IsAllocationSite()) {
   1904       Handle<AllocationSite> new_site =
   1905           isolate()->factory()->NewAllocationSite();
   1906       vector->set(slot->value(), *new_site);
   1907     }
   1908 
   1909     CallIC_ArrayStub stub(isolate(), state);
   1910     set_target(*stub.GetCode());
   1911     Handle<String> name;
   1912     if (array_function->shared()->name()->IsString()) {
   1913       name = Handle<String>(String::cast(array_function->shared()->name()),
   1914                             isolate());
   1915     }
   1916 
   1917     IC::State new_state = FeedbackToState(vector, slot);
   1918     OnTypeFeedbackChanged(isolate(), address(), old_state, new_state, true);
   1919     TRACE_VECTOR_IC("CallIC (custom handler)", name, old_state, new_state);
   1920     return true;
   1921   }
   1922   return false;
   1923 }
   1924 
   1925 
   1926 void CallIC::PatchMegamorphic(Handle<Object> function,
   1927                               Handle<TypeFeedbackVector> vector,
   1928                               Handle<Smi> slot) {
   1929   CallICState state(target()->extra_ic_state());
   1930   IC::State old_state = FeedbackToState(vector, slot);
   1931 
   1932   // We are going generic.
   1933   vector->set(slot->value(),
   1934               *TypeFeedbackVector::MegamorphicSentinel(isolate()),
   1935               SKIP_WRITE_BARRIER);
   1936 
   1937   CallICStub stub(isolate(), state);
   1938   Handle<Code> code = stub.GetCode();
   1939   set_target(*code);
   1940 
   1941   Handle<Object> name = isolate()->factory()->empty_string();
   1942   if (function->IsJSFunction()) {
   1943     Handle<JSFunction> js_function = Handle<JSFunction>::cast(function);
   1944     name = handle(js_function->shared()->name(), isolate());
   1945   }
   1946 
   1947   IC::State new_state = FeedbackToState(vector, slot);
   1948   OnTypeFeedbackChanged(isolate(), address(), old_state, new_state, true);
   1949   TRACE_VECTOR_IC("CallIC", name, old_state, new_state);
   1950 }
   1951 
   1952 
   1953 void CallIC::HandleMiss(Handle<Object> receiver, Handle<Object> function,
   1954                         Handle<TypeFeedbackVector> vector, Handle<Smi> slot) {
   1955   CallICState state(target()->extra_ic_state());
   1956   IC::State old_state = FeedbackToState(vector, slot);
   1957   Handle<Object> name = isolate()->factory()->empty_string();
   1958   Object* feedback = vector->get(slot->value());
   1959 
   1960   // Hand-coded MISS handling is easier if CallIC slots don't contain smis.
   1961   DCHECK(!feedback->IsSmi());
   1962 
   1963   if (feedback->IsJSFunction() || !function->IsJSFunction()) {
   1964     // We are going generic.
   1965     vector->set(slot->value(),
   1966                 *TypeFeedbackVector::MegamorphicSentinel(isolate()),
   1967                 SKIP_WRITE_BARRIER);
   1968   } else {
   1969     // The feedback is either uninitialized or an allocation site.
   1970     // It might be an allocation site because if we re-compile the full code
   1971     // to add deoptimization support, we call with the default call-ic, and
   1972     // merely need to patch the target to match the feedback.
   1973     // TODO(mvstanton): the better approach is to dispense with patching
   1974     // altogether, which is in progress.
   1975     DCHECK(feedback == *TypeFeedbackVector::UninitializedSentinel(isolate()) ||
   1976            feedback->IsAllocationSite());
   1977 
   1978     // Do we want to install a custom handler?
   1979     if (FLAG_use_ic &&
   1980         DoCustomHandler(receiver, function, vector, slot, state)) {
   1981       return;
   1982     }
   1983 
   1984     vector->set(slot->value(), *function);
   1985   }
   1986 
   1987   if (function->IsJSFunction()) {
   1988     Handle<JSFunction> js_function = Handle<JSFunction>::cast(function);
   1989     name = handle(js_function->shared()->name(), isolate());
   1990   }
   1991 
   1992   IC::State new_state = FeedbackToState(vector, slot);
   1993   OnTypeFeedbackChanged(isolate(), address(), old_state, new_state, true);
   1994   TRACE_VECTOR_IC("CallIC", name, old_state, new_state);
   1995 }
   1996 
   1997 
   1998 #undef TRACE_IC
   1999 
   2000 
   2001 // ----------------------------------------------------------------------------
   2002 // Static IC stub generators.
   2003 //
   2004 
   2005 // Used from ic-<arch>.cc.
   2006 RUNTIME_FUNCTION(CallIC_Miss) {
   2007   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2008   HandleScope scope(isolate);
   2009   DCHECK(args.length() == 4);
   2010   CallIC ic(isolate);
   2011   Handle<Object> receiver = args.at<Object>(0);
   2012   Handle<Object> function = args.at<Object>(1);
   2013   Handle<TypeFeedbackVector> vector = args.at<TypeFeedbackVector>(2);
   2014   Handle<Smi> slot = args.at<Smi>(3);
   2015   ic.HandleMiss(receiver, function, vector, slot);
   2016   return *function;
   2017 }
   2018 
   2019 
   2020 RUNTIME_FUNCTION(CallIC_Customization_Miss) {
   2021   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2022   HandleScope scope(isolate);
   2023   DCHECK(args.length() == 4);
   2024   // A miss on a custom call ic always results in going megamorphic.
   2025   CallIC ic(isolate);
   2026   Handle<Object> function = args.at<Object>(1);
   2027   Handle<TypeFeedbackVector> vector = args.at<TypeFeedbackVector>(2);
   2028   Handle<Smi> slot = args.at<Smi>(3);
   2029   ic.PatchMegamorphic(function, vector, slot);
   2030   return *function;
   2031 }
   2032 
   2033 
   2034 // Used from ic-<arch>.cc.
   2035 RUNTIME_FUNCTION(LoadIC_Miss) {
   2036   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2037   HandleScope scope(isolate);
   2038   DCHECK(args.length() == 2);
   2039   LoadIC ic(IC::NO_EXTRA_FRAME, isolate);
   2040   Handle<Object> receiver = args.at<Object>(0);
   2041   Handle<Name> key = args.at<Name>(1);
   2042   ic.UpdateState(receiver, key);
   2043   Handle<Object> result;
   2044   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   2045   return *result;
   2046 }
   2047 
   2048 
   2049 // Used from ic-<arch>.cc
   2050 RUNTIME_FUNCTION(KeyedLoadIC_Miss) {
   2051   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2052   HandleScope scope(isolate);
   2053   DCHECK(args.length() == 2);
   2054   KeyedLoadIC ic(IC::NO_EXTRA_FRAME, isolate);
   2055   Handle<Object> receiver = args.at<Object>(0);
   2056   Handle<Object> key = args.at<Object>(1);
   2057   ic.UpdateState(receiver, key);
   2058   Handle<Object> result;
   2059   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   2060   return *result;
   2061 }
   2062 
   2063 
   2064 RUNTIME_FUNCTION(KeyedLoadIC_MissFromStubFailure) {
   2065   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2066   HandleScope scope(isolate);
   2067   DCHECK(args.length() == 2);
   2068   KeyedLoadIC ic(IC::EXTRA_CALL_FRAME, isolate);
   2069   Handle<Object> receiver = args.at<Object>(0);
   2070   Handle<Object> key = args.at<Object>(1);
   2071   ic.UpdateState(receiver, key);
   2072   Handle<Object> result;
   2073   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result, ic.Load(receiver, key));
   2074   return *result;
   2075 }
   2076 
   2077 
   2078 // Used from ic-<arch>.cc.
   2079 RUNTIME_FUNCTION(StoreIC_Miss) {
   2080   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2081   HandleScope scope(isolate);
   2082   DCHECK(args.length() == 3);
   2083   StoreIC ic(IC::NO_EXTRA_FRAME, isolate);
   2084   Handle<Object> receiver = args.at<Object>(0);
   2085   Handle<String> key = args.at<String>(1);
   2086   ic.UpdateState(receiver, key);
   2087   Handle<Object> result;
   2088   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2089       isolate, result, ic.Store(receiver, key, args.at<Object>(2)));
   2090   return *result;
   2091 }
   2092 
   2093 
   2094 RUNTIME_FUNCTION(StoreIC_MissFromStubFailure) {
   2095   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2096   HandleScope scope(isolate);
   2097   DCHECK(args.length() == 3);
   2098   StoreIC ic(IC::EXTRA_CALL_FRAME, isolate);
   2099   Handle<Object> receiver = args.at<Object>(0);
   2100   Handle<String> key = args.at<String>(1);
   2101   ic.UpdateState(receiver, key);
   2102   Handle<Object> result;
   2103   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2104       isolate, result, ic.Store(receiver, key, args.at<Object>(2)));
   2105   return *result;
   2106 }
   2107 
   2108 
   2109 // Extend storage is called in a store inline cache when
   2110 // it is necessary to extend the properties array of a
   2111 // JSObject.
   2112 RUNTIME_FUNCTION(SharedStoreIC_ExtendStorage) {
   2113   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2114   HandleScope shs(isolate);
   2115   DCHECK(args.length() == 3);
   2116 
   2117   // Convert the parameters
   2118   Handle<JSObject> object = args.at<JSObject>(0);
   2119   Handle<Map> transition = args.at<Map>(1);
   2120   Handle<Object> value = args.at<Object>(2);
   2121 
   2122   // Check the object has run out out property space.
   2123   DCHECK(object->HasFastProperties());
   2124   DCHECK(object->map()->unused_property_fields() == 0);
   2125 
   2126   JSObject::MigrateToNewProperty(object, transition, value);
   2127 
   2128   // Return the stored value.
   2129   return *value;
   2130 }
   2131 
   2132 
   2133 // Used from ic-<arch>.cc.
   2134 RUNTIME_FUNCTION(KeyedStoreIC_Miss) {
   2135   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2136   HandleScope scope(isolate);
   2137   DCHECK(args.length() == 3);
   2138   KeyedStoreIC ic(IC::NO_EXTRA_FRAME, isolate);
   2139   Handle<Object> receiver = args.at<Object>(0);
   2140   Handle<Object> key = args.at<Object>(1);
   2141   ic.UpdateState(receiver, key);
   2142   Handle<Object> result;
   2143   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2144       isolate, result, ic.Store(receiver, key, args.at<Object>(2)));
   2145   return *result;
   2146 }
   2147 
   2148 
   2149 RUNTIME_FUNCTION(KeyedStoreIC_MissFromStubFailure) {
   2150   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2151   HandleScope scope(isolate);
   2152   DCHECK(args.length() == 3);
   2153   KeyedStoreIC ic(IC::EXTRA_CALL_FRAME, isolate);
   2154   Handle<Object> receiver = args.at<Object>(0);
   2155   Handle<Object> key = args.at<Object>(1);
   2156   ic.UpdateState(receiver, key);
   2157   Handle<Object> result;
   2158   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2159       isolate, result, ic.Store(receiver, key, args.at<Object>(2)));
   2160   return *result;
   2161 }
   2162 
   2163 
   2164 RUNTIME_FUNCTION(StoreIC_Slow) {
   2165   HandleScope scope(isolate);
   2166   DCHECK(args.length() == 3);
   2167   StoreIC ic(IC::NO_EXTRA_FRAME, isolate);
   2168   Handle<Object> object = args.at<Object>(0);
   2169   Handle<Object> key = args.at<Object>(1);
   2170   Handle<Object> value = args.at<Object>(2);
   2171   StrictMode strict_mode = ic.strict_mode();
   2172   Handle<Object> result;
   2173   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2174       isolate, result,
   2175       Runtime::SetObjectProperty(isolate, object, key, value, strict_mode));
   2176   return *result;
   2177 }
   2178 
   2179 
   2180 RUNTIME_FUNCTION(KeyedStoreIC_Slow) {
   2181   HandleScope scope(isolate);
   2182   DCHECK(args.length() == 3);
   2183   KeyedStoreIC ic(IC::NO_EXTRA_FRAME, isolate);
   2184   Handle<Object> object = args.at<Object>(0);
   2185   Handle<Object> key = args.at<Object>(1);
   2186   Handle<Object> value = args.at<Object>(2);
   2187   StrictMode strict_mode = ic.strict_mode();
   2188   Handle<Object> result;
   2189   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2190       isolate, result,
   2191       Runtime::SetObjectProperty(isolate, object, key, value, strict_mode));
   2192   return *result;
   2193 }
   2194 
   2195 
   2196 RUNTIME_FUNCTION(ElementsTransitionAndStoreIC_Miss) {
   2197   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2198   HandleScope scope(isolate);
   2199   DCHECK(args.length() == 4);
   2200   KeyedStoreIC ic(IC::EXTRA_CALL_FRAME, isolate);
   2201   Handle<Object> value = args.at<Object>(0);
   2202   Handle<Map> map = args.at<Map>(1);
   2203   Handle<Object> key = args.at<Object>(2);
   2204   Handle<Object> object = args.at<Object>(3);
   2205   StrictMode strict_mode = ic.strict_mode();
   2206   if (object->IsJSObject()) {
   2207     JSObject::TransitionElementsKind(Handle<JSObject>::cast(object),
   2208                                      map->elements_kind());
   2209   }
   2210   Handle<Object> result;
   2211   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2212       isolate, result,
   2213       Runtime::SetObjectProperty(isolate, object, key, value, strict_mode));
   2214   return *result;
   2215 }
   2216 
   2217 
   2218 MaybeHandle<Object> BinaryOpIC::Transition(
   2219     Handle<AllocationSite> allocation_site, Handle<Object> left,
   2220     Handle<Object> right) {
   2221   BinaryOpICState state(isolate(), target()->extra_ic_state());
   2222 
   2223   // Compute the actual result using the builtin for the binary operation.
   2224   Object* builtin = isolate()->js_builtins_object()->javascript_builtin(
   2225       TokenToJSBuiltin(state.op()));
   2226   Handle<JSFunction> function = handle(JSFunction::cast(builtin), isolate());
   2227   Handle<Object> result;
   2228   ASSIGN_RETURN_ON_EXCEPTION(
   2229       isolate(), result, Execution::Call(isolate(), function, left, 1, &right),
   2230       Object);
   2231 
   2232   // Execution::Call can execute arbitrary JavaScript, hence potentially
   2233   // update the state of this very IC, so we must update the stored state.
   2234   UpdateTarget();
   2235   // Compute the new state.
   2236   BinaryOpICState old_state(isolate(), target()->extra_ic_state());
   2237   state.Update(left, right, result);
   2238 
   2239   // Check if we have a string operation here.
   2240   Handle<Code> target;
   2241   if (!allocation_site.is_null() || state.ShouldCreateAllocationMementos()) {
   2242     // Setup the allocation site on-demand.
   2243     if (allocation_site.is_null()) {
   2244       allocation_site = isolate()->factory()->NewAllocationSite();
   2245     }
   2246 
   2247     // Install the stub with an allocation site.
   2248     BinaryOpICWithAllocationSiteStub stub(isolate(), state);
   2249     target = stub.GetCodeCopyFromTemplate(allocation_site);
   2250 
   2251     // Sanity check the trampoline stub.
   2252     DCHECK_EQ(*allocation_site, target->FindFirstAllocationSite());
   2253   } else {
   2254     // Install the generic stub.
   2255     BinaryOpICStub stub(isolate(), state);
   2256     target = stub.GetCode();
   2257 
   2258     // Sanity check the generic stub.
   2259     DCHECK_EQ(NULL, target->FindFirstAllocationSite());
   2260   }
   2261   set_target(*target);
   2262 
   2263   if (FLAG_trace_ic) {
   2264     OFStream os(stdout);
   2265     os << "[BinaryOpIC" << old_state << " => " << state << " @ "
   2266        << static_cast<void*>(*target) << " <- ";
   2267     JavaScriptFrame::PrintTop(isolate(), stdout, false, true);
   2268     if (!allocation_site.is_null()) {
   2269       os << " using allocation site " << static_cast<void*>(*allocation_site);
   2270     }
   2271     os << "]" << endl;
   2272   }
   2273 
   2274   // Patch the inlined smi code as necessary.
   2275   if (!old_state.UseInlinedSmiCode() && state.UseInlinedSmiCode()) {
   2276     PatchInlinedSmiCode(address(), ENABLE_INLINED_SMI_CHECK);
   2277   } else if (old_state.UseInlinedSmiCode() && !state.UseInlinedSmiCode()) {
   2278     PatchInlinedSmiCode(address(), DISABLE_INLINED_SMI_CHECK);
   2279   }
   2280 
   2281   return result;
   2282 }
   2283 
   2284 
   2285 RUNTIME_FUNCTION(BinaryOpIC_Miss) {
   2286   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2287   HandleScope scope(isolate);
   2288   DCHECK_EQ(2, args.length());
   2289   Handle<Object> left = args.at<Object>(BinaryOpICStub::kLeft);
   2290   Handle<Object> right = args.at<Object>(BinaryOpICStub::kRight);
   2291   BinaryOpIC ic(isolate);
   2292   Handle<Object> result;
   2293   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2294       isolate, result,
   2295       ic.Transition(Handle<AllocationSite>::null(), left, right));
   2296   return *result;
   2297 }
   2298 
   2299 
   2300 RUNTIME_FUNCTION(BinaryOpIC_MissWithAllocationSite) {
   2301   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2302   HandleScope scope(isolate);
   2303   DCHECK_EQ(3, args.length());
   2304   Handle<AllocationSite> allocation_site =
   2305       args.at<AllocationSite>(BinaryOpWithAllocationSiteStub::kAllocationSite);
   2306   Handle<Object> left = args.at<Object>(BinaryOpWithAllocationSiteStub::kLeft);
   2307   Handle<Object> right =
   2308       args.at<Object>(BinaryOpWithAllocationSiteStub::kRight);
   2309   BinaryOpIC ic(isolate);
   2310   Handle<Object> result;
   2311   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2312       isolate, result, ic.Transition(allocation_site, left, right));
   2313   return *result;
   2314 }
   2315 
   2316 
   2317 Code* CompareIC::GetRawUninitialized(Isolate* isolate, Token::Value op) {
   2318   CompareICStub stub(isolate, op, CompareICState::UNINITIALIZED,
   2319                      CompareICState::UNINITIALIZED,
   2320                      CompareICState::UNINITIALIZED);
   2321   Code* code = NULL;
   2322   CHECK(stub.FindCodeInCache(&code));
   2323   return code;
   2324 }
   2325 
   2326 
   2327 Handle<Code> CompareIC::GetUninitialized(Isolate* isolate, Token::Value op) {
   2328   CompareICStub stub(isolate, op, CompareICState::UNINITIALIZED,
   2329                      CompareICState::UNINITIALIZED,
   2330                      CompareICState::UNINITIALIZED);
   2331   return stub.GetCode();
   2332 }
   2333 
   2334 
   2335 Code* CompareIC::UpdateCaches(Handle<Object> x, Handle<Object> y) {
   2336   HandleScope scope(isolate());
   2337   CompareICStub old_stub(target()->stub_key(), isolate());
   2338   CompareICState::State new_left =
   2339       CompareICState::NewInputState(old_stub.left(), x);
   2340   CompareICState::State new_right =
   2341       CompareICState::NewInputState(old_stub.right(), y);
   2342   CompareICState::State state = CompareICState::TargetState(
   2343       old_stub.state(), old_stub.left(), old_stub.right(), op_,
   2344       HasInlinedSmiCode(address()), x, y);
   2345   CompareICStub stub(isolate(), op_, new_left, new_right, state);
   2346   if (state == CompareICState::KNOWN_OBJECT) {
   2347     stub.set_known_map(
   2348         Handle<Map>(Handle<JSObject>::cast(x)->map(), isolate()));
   2349   }
   2350   Handle<Code> new_target = stub.GetCode();
   2351   set_target(*new_target);
   2352 
   2353   if (FLAG_trace_ic) {
   2354     PrintF("[CompareIC in ");
   2355     JavaScriptFrame::PrintTop(isolate(), stdout, false, true);
   2356     PrintF(" ((%s+%s=%s)->(%s+%s=%s))#%s @ %p]\n",
   2357            CompareICState::GetStateName(old_stub.left()),
   2358            CompareICState::GetStateName(old_stub.right()),
   2359            CompareICState::GetStateName(old_stub.state()),
   2360            CompareICState::GetStateName(new_left),
   2361            CompareICState::GetStateName(new_right),
   2362            CompareICState::GetStateName(state), Token::Name(op_),
   2363            static_cast<void*>(*stub.GetCode()));
   2364   }
   2365 
   2366   // Activate inlined smi code.
   2367   if (old_stub.state() == CompareICState::UNINITIALIZED) {
   2368     PatchInlinedSmiCode(address(), ENABLE_INLINED_SMI_CHECK);
   2369   }
   2370 
   2371   return *new_target;
   2372 }
   2373 
   2374 
   2375 // Used from CompareICStub::GenerateMiss in code-stubs-<arch>.cc.
   2376 RUNTIME_FUNCTION(CompareIC_Miss) {
   2377   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2378   HandleScope scope(isolate);
   2379   DCHECK(args.length() == 3);
   2380   CompareIC ic(isolate, static_cast<Token::Value>(args.smi_at(2)));
   2381   return ic.UpdateCaches(args.at<Object>(0), args.at<Object>(1));
   2382 }
   2383 
   2384 
   2385 void CompareNilIC::Clear(Address address, Code* target,
   2386                          ConstantPoolArray* constant_pool) {
   2387   if (IsCleared(target)) return;
   2388   ExtraICState state = target->extra_ic_state();
   2389 
   2390   CompareNilICStub stub(target->GetIsolate(), state,
   2391                         HydrogenCodeStub::UNINITIALIZED);
   2392   stub.ClearState();
   2393 
   2394   Code* code = NULL;
   2395   CHECK(stub.FindCodeInCache(&code));
   2396 
   2397   SetTargetAtAddress(address, code, constant_pool);
   2398 }
   2399 
   2400 
   2401 Handle<Object> CompareNilIC::DoCompareNilSlow(Isolate* isolate, NilValue nil,
   2402                                               Handle<Object> object) {
   2403   if (object->IsNull() || object->IsUndefined()) {
   2404     return handle(Smi::FromInt(true), isolate);
   2405   }
   2406   return handle(Smi::FromInt(object->IsUndetectableObject()), isolate);
   2407 }
   2408 
   2409 
   2410 Handle<Object> CompareNilIC::CompareNil(Handle<Object> object) {
   2411   ExtraICState extra_ic_state = target()->extra_ic_state();
   2412 
   2413   CompareNilICStub stub(isolate(), extra_ic_state);
   2414 
   2415   // Extract the current supported types from the patched IC and calculate what
   2416   // types must be supported as a result of the miss.
   2417   bool already_monomorphic = stub.IsMonomorphic();
   2418 
   2419   stub.UpdateStatus(object);
   2420 
   2421   NilValue nil = stub.nil_value();
   2422 
   2423   // Find or create the specialized stub to support the new set of types.
   2424   Handle<Code> code;
   2425   if (stub.IsMonomorphic()) {
   2426     Handle<Map> monomorphic_map(already_monomorphic && FirstTargetMap() != NULL
   2427                                     ? FirstTargetMap()
   2428                                     : HeapObject::cast(*object)->map());
   2429     code = PropertyICCompiler::ComputeCompareNil(monomorphic_map, &stub);
   2430   } else {
   2431     code = stub.GetCode();
   2432   }
   2433   set_target(*code);
   2434   return DoCompareNilSlow(isolate(), nil, object);
   2435 }
   2436 
   2437 
   2438 RUNTIME_FUNCTION(CompareNilIC_Miss) {
   2439   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2440   HandleScope scope(isolate);
   2441   Handle<Object> object = args.at<Object>(0);
   2442   CompareNilIC ic(isolate);
   2443   return *ic.CompareNil(object);
   2444 }
   2445 
   2446 
   2447 RUNTIME_FUNCTION(Unreachable) {
   2448   UNREACHABLE();
   2449   CHECK(false);
   2450   return isolate->heap()->undefined_value();
   2451 }
   2452 
   2453 
   2454 Builtins::JavaScript BinaryOpIC::TokenToJSBuiltin(Token::Value op) {
   2455   switch (op) {
   2456     default:
   2457       UNREACHABLE();
   2458     case Token::ADD:
   2459       return Builtins::ADD;
   2460       break;
   2461     case Token::SUB:
   2462       return Builtins::SUB;
   2463       break;
   2464     case Token::MUL:
   2465       return Builtins::MUL;
   2466       break;
   2467     case Token::DIV:
   2468       return Builtins::DIV;
   2469       break;
   2470     case Token::MOD:
   2471       return Builtins::MOD;
   2472       break;
   2473     case Token::BIT_OR:
   2474       return Builtins::BIT_OR;
   2475       break;
   2476     case Token::BIT_AND:
   2477       return Builtins::BIT_AND;
   2478       break;
   2479     case Token::BIT_XOR:
   2480       return Builtins::BIT_XOR;
   2481       break;
   2482     case Token::SAR:
   2483       return Builtins::SAR;
   2484       break;
   2485     case Token::SHR:
   2486       return Builtins::SHR;
   2487       break;
   2488     case Token::SHL:
   2489       return Builtins::SHL;
   2490       break;
   2491   }
   2492 }
   2493 
   2494 
   2495 Handle<Object> ToBooleanIC::ToBoolean(Handle<Object> object) {
   2496   ToBooleanStub stub(isolate(), target()->extra_ic_state());
   2497   bool to_boolean_value = stub.UpdateStatus(object);
   2498   Handle<Code> code = stub.GetCode();
   2499   set_target(*code);
   2500   return handle(Smi::FromInt(to_boolean_value ? 1 : 0), isolate());
   2501 }
   2502 
   2503 
   2504 RUNTIME_FUNCTION(ToBooleanIC_Miss) {
   2505   TimerEventScope<TimerEventIcMiss> timer(isolate);
   2506   DCHECK(args.length() == 1);
   2507   HandleScope scope(isolate);
   2508   Handle<Object> object = args.at<Object>(0);
   2509   ToBooleanIC ic(isolate);
   2510   return *ic.ToBoolean(object);
   2511 }
   2512 
   2513 
   2514 RUNTIME_FUNCTION(StoreCallbackProperty) {
   2515   Handle<JSObject> receiver = args.at<JSObject>(0);
   2516   Handle<JSObject> holder = args.at<JSObject>(1);
   2517   Handle<ExecutableAccessorInfo> callback = args.at<ExecutableAccessorInfo>(2);
   2518   Handle<Name> name = args.at<Name>(3);
   2519   Handle<Object> value = args.at<Object>(4);
   2520   HandleScope scope(isolate);
   2521 
   2522   DCHECK(callback->IsCompatibleReceiver(*receiver));
   2523 
   2524   Address setter_address = v8::ToCData<Address>(callback->setter());
   2525   v8::AccessorNameSetterCallback fun =
   2526       FUNCTION_CAST<v8::AccessorNameSetterCallback>(setter_address);
   2527   DCHECK(fun != NULL);
   2528 
   2529   LOG(isolate, ApiNamedPropertyAccess("store", *receiver, *name));
   2530   PropertyCallbackArguments custom_args(isolate, callback->data(), *receiver,
   2531                                         *holder);
   2532   custom_args.Call(fun, v8::Utils::ToLocal(name), v8::Utils::ToLocal(value));
   2533   RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
   2534   return *value;
   2535 }
   2536 
   2537 
   2538 /**
   2539  * Attempts to load a property with an interceptor (which must be present),
   2540  * but doesn't search the prototype chain.
   2541  *
   2542  * Returns |Heap::no_interceptor_result_sentinel()| if interceptor doesn't
   2543  * provide any value for the given name.
   2544  */
   2545 RUNTIME_FUNCTION(LoadPropertyWithInterceptorOnly) {
   2546   DCHECK(args.length() == NamedLoadHandlerCompiler::kInterceptorArgsLength);
   2547   Handle<Name> name_handle =
   2548       args.at<Name>(NamedLoadHandlerCompiler::kInterceptorArgsNameIndex);
   2549   Handle<InterceptorInfo> interceptor_info = args.at<InterceptorInfo>(
   2550       NamedLoadHandlerCompiler::kInterceptorArgsInfoIndex);
   2551 
   2552   // TODO(rossberg): Support symbols in the API.
   2553   if (name_handle->IsSymbol())
   2554     return isolate->heap()->no_interceptor_result_sentinel();
   2555   Handle<String> name = Handle<String>::cast(name_handle);
   2556 
   2557   Address getter_address = v8::ToCData<Address>(interceptor_info->getter());
   2558   v8::NamedPropertyGetterCallback getter =
   2559       FUNCTION_CAST<v8::NamedPropertyGetterCallback>(getter_address);
   2560   DCHECK(getter != NULL);
   2561 
   2562   Handle<JSObject> receiver =
   2563       args.at<JSObject>(NamedLoadHandlerCompiler::kInterceptorArgsThisIndex);
   2564   Handle<JSObject> holder =
   2565       args.at<JSObject>(NamedLoadHandlerCompiler::kInterceptorArgsHolderIndex);
   2566   PropertyCallbackArguments callback_args(isolate, interceptor_info->data(),
   2567                                           *receiver, *holder);
   2568   {
   2569     // Use the interceptor getter.
   2570     HandleScope scope(isolate);
   2571     v8::Handle<v8::Value> r =
   2572         callback_args.Call(getter, v8::Utils::ToLocal(name));
   2573     RETURN_FAILURE_IF_SCHEDULED_EXCEPTION(isolate);
   2574     if (!r.IsEmpty()) {
   2575       Handle<Object> result = v8::Utils::OpenHandle(*r);
   2576       result->VerifyApiCallResultType();
   2577       return *v8::Utils::OpenHandle(*r);
   2578     }
   2579   }
   2580 
   2581   return isolate->heap()->no_interceptor_result_sentinel();
   2582 }
   2583 
   2584 
   2585 static Object* ThrowReferenceError(Isolate* isolate, Name* name) {
   2586   // If the load is non-contextual, just return the undefined result.
   2587   // Note that both keyed and non-keyed loads may end up here.
   2588   HandleScope scope(isolate);
   2589   LoadIC ic(IC::NO_EXTRA_FRAME, isolate);
   2590   if (ic.contextual_mode() != CONTEXTUAL) {
   2591     return isolate->heap()->undefined_value();
   2592   }
   2593 
   2594   // Throw a reference error.
   2595   Handle<Name> name_handle(name);
   2596   THROW_NEW_ERROR_RETURN_FAILURE(
   2597       isolate, NewReferenceError("not_defined", HandleVector(&name_handle, 1)));
   2598 }
   2599 
   2600 
   2601 /**
   2602  * Loads a property with an interceptor performing post interceptor
   2603  * lookup if interceptor failed.
   2604  */
   2605 RUNTIME_FUNCTION(LoadPropertyWithInterceptor) {
   2606   HandleScope scope(isolate);
   2607   DCHECK(args.length() == NamedLoadHandlerCompiler::kInterceptorArgsLength);
   2608   Handle<Name> name =
   2609       args.at<Name>(NamedLoadHandlerCompiler::kInterceptorArgsNameIndex);
   2610   Handle<JSObject> receiver =
   2611       args.at<JSObject>(NamedLoadHandlerCompiler::kInterceptorArgsThisIndex);
   2612   Handle<JSObject> holder =
   2613       args.at<JSObject>(NamedLoadHandlerCompiler::kInterceptorArgsHolderIndex);
   2614 
   2615   Handle<Object> result;
   2616   LookupIterator it(receiver, name, holder);
   2617   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, result,
   2618                                      JSObject::GetProperty(&it));
   2619 
   2620   if (it.IsFound()) return *result;
   2621 
   2622   return ThrowReferenceError(isolate, Name::cast(args[0]));
   2623 }
   2624 
   2625 
   2626 RUNTIME_FUNCTION(StorePropertyWithInterceptor) {
   2627   HandleScope scope(isolate);
   2628   DCHECK(args.length() == 3);
   2629   StoreIC ic(IC::NO_EXTRA_FRAME, isolate);
   2630   Handle<JSObject> receiver = args.at<JSObject>(0);
   2631   Handle<Name> name = args.at<Name>(1);
   2632   Handle<Object> value = args.at<Object>(2);
   2633 #ifdef DEBUG
   2634   PrototypeIterator iter(isolate, receiver,
   2635                          PrototypeIterator::START_AT_RECEIVER);
   2636   bool found = false;
   2637   while (!iter.IsAtEnd(PrototypeIterator::END_AT_NON_HIDDEN)) {
   2638     Handle<Object> current = PrototypeIterator::GetCurrent(iter);
   2639     if (current->IsJSObject() &&
   2640         Handle<JSObject>::cast(current)->HasNamedInterceptor()) {
   2641       found = true;
   2642       break;
   2643     }
   2644   }
   2645   DCHECK(found);
   2646 #endif
   2647   Handle<Object> result;
   2648   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2649       isolate, result,
   2650       JSObject::SetProperty(receiver, name, value, ic.strict_mode()));
   2651   return *result;
   2652 }
   2653 
   2654 
   2655 RUNTIME_FUNCTION(LoadElementWithInterceptor) {
   2656   HandleScope scope(isolate);
   2657   Handle<JSObject> receiver = args.at<JSObject>(0);
   2658   DCHECK(args.smi_at(1) >= 0);
   2659   uint32_t index = args.smi_at(1);
   2660   Handle<Object> result;
   2661   ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
   2662       isolate, result,
   2663       JSObject::GetElementWithInterceptor(receiver, receiver, index));
   2664   return *result;
   2665 }
   2666 
   2667 
   2668 RUNTIME_FUNCTION(VectorLoadIC_MissFromStubFailure) {
   2669   // TODO(mvstanton): To be enabled when ICs can accept a vector and slot
   2670   return NULL;
   2671 }
   2672 
   2673 
   2674 RUNTIME_FUNCTION(VectorKeyedLoadIC_MissFromStubFailure) {
   2675   // TODO(mvstanton): To be enabled when ICs can accept a vector and slot
   2676   return NULL;
   2677 }
   2678 
   2679 
   2680 static const Address IC_utilities[] = {
   2681 #define ADDR(name) FUNCTION_ADDR(name),
   2682     IC_UTIL_LIST(ADDR) NULL
   2683 #undef ADDR
   2684 };
   2685 
   2686 
   2687 Address IC::AddressFromUtilityId(IC::UtilityId id) { return IC_utilities[id]; }
   2688 }
   2689 }  // namespace v8::internal
   2690