Rollback trunk to 3.21.15.

src/ic.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 531 matching lines @@
     int index = frame->ComputeExpressionsCount() - (argc + 1);
     frame->SetExpression(index, *isolate()->factory()->ToObject(object));
   }
 }
 
 
 MaybeObject* CallICBase::LoadFunction(State state,
                                       Code::ExtraICState extra_ic_state,
                                       Handle<Object> object,
                                       Handle<String> name) {
-  bool use_ic = FLAG_use_ic;
   if (object->IsJSObject()) {
     Handle<JSObject> receiver = Handle<JSObject>::cast(object);
     if (receiver->map()->is_deprecated()) {
-      use_ic = false;
       JSObject::MigrateInstance(receiver);
     }
   }
 
   // If the object is undefined or null it's illegal to try to get any
   // of its properties; throw a TypeError in that case.
   if (object->IsUndefined() || object->IsNull()) {
     return TypeError("non_object_property_call", object, name);
   }
 
@@ skipping 18 matching lines @@
 
   if (!lookup.IsFound()) {
     // If the object does not have the requested property, check which
     // exception we need to throw.
     return IsUndeclaredGlobal(object)
         ? ReferenceError("not_defined", name)
         : TypeError("undefined_method", object, name);
   }
 
   // Lookup is valid: Update inline cache and stub cache.
-  if (use_ic) UpdateCaches(&lookup, state, extra_ic_state, object, name);
+  if (FLAG_use_ic) {
+    UpdateCaches(&lookup, state, extra_ic_state, object, name);
+  }
 
   // Get the property.
   PropertyAttributes attr;
   Handle<Object> result =
       Object::GetProperty(object, object, &lookup, name, &attr);
   RETURN_IF_EMPTY_HANDLE(isolate(), result);
 
   if (lookup.IsInterceptor() && attr == ABSENT) {
     // If the object does not have the requested property, check which
     // exception we need to throw.
@@ skipping 206 matching lines @@
 MaybeObject* KeyedCallIC::LoadFunction(State state,
                                        Handle<Object> object,
                                        Handle<Object> key) {
   if (key->IsInternalizedString()) {
     return CallICBase::LoadFunction(state,
                                     Code::kNoExtraICState,
                                     object,
                                     Handle<String>::cast(key));
   }
 
-  bool use_ic = FLAG_use_ic && !object->IsAccessCheckNeeded();
   if (object->IsJSObject()) {
     Handle<JSObject> receiver = Handle<JSObject>::cast(object);
     if (receiver->map()->is_deprecated()) {
-      use_ic = false;
       JSObject::MigrateInstance(receiver);
     }
   }
 
   if (object->IsUndefined() || object->IsNull()) {
     return TypeError("non_object_property_call", object, key);
   }
 
+  bool use_ic = FLAG_use_ic && !object->IsAccessCheckNeeded();
   ASSERT(!(use_ic && object->IsJSGlobalProxy()));
 
   if (use_ic && state != MEGAMORPHIC) {
     int argc = target()->arguments_count();
     Handle<Code> stub = isolate()->stub_cache()->ComputeCallMegamorphic(
         argc, Code::KEYED_CALL_IC, Code::kNoExtraICState);
     if (object->IsJSObject()) {
       Handle<JSObject> receiver = Handle<JSObject>::cast(object);
       if (receiver->elements()->map() ==
           isolate()->heap()->non_strict_arguments_elements_map()) {
@@ skipping 23 matching lines @@
 
 MaybeObject* LoadIC::Load(State state,
                           Handle<Object> object,
                           Handle<String> name) {
   // If the object is undefined or null it's illegal to try to get any
   // of its properties; throw a TypeError in that case.
   if (object->IsUndefined() || object->IsNull()) {
     return TypeError("non_object_property_load", object, name);
   }
 
-  bool use_ic = FLAG_use_ic;
-
-  if (use_ic) {
+  if (FLAG_use_ic) {
     // Use specialized code for getting the length of strings and
     // string wrapper objects.  The length property of string wrapper
     // objects is read-only and therefore always returns the length of
     // the underlying string value.  See ECMA-262 15.5.5.1.
-    if (object->IsStringWrapper() &&
+    if ((object->IsString() || object->IsStringWrapper()) &&
         name->Equals(isolate()->heap()->length_string())) {
       Handle<Code> stub;
       if (state == UNINITIALIZED) {
         stub = pre_monomorphic_stub();
-      } else if (state == PREMONOMORPHIC || state == MONOMORPHIC) {
-        StringLengthStub string_length_stub(kind());
+      } else if (state == PREMONOMORPHIC) {
+        StringLengthStub string_length_stub(kind(), !object->IsString());
+        stub = string_length_stub.GetCode(isolate());
+      } else if (state == MONOMORPHIC && object->IsStringWrapper()) {
+        StringLengthStub string_length_stub(kind(), true);
         stub = string_length_stub.GetCode(isolate());
       } else if (state != MEGAMORPHIC) {
         ASSERT(state != GENERIC);
         stub = megamorphic_stub();
       }
       if (!stub.is_null()) {
         set_target(*stub);
 #ifdef DEBUG
-        if (FLAG_trace_ic) PrintF("[LoadIC : +#length /stringwrapper]\n");
+        if (FLAG_trace_ic) PrintF("[LoadIC : +#length /string]\n");
 #endif
       }
       // Get the string if we have a string wrapper object.
-      String* string = String::cast(JSValue::cast(*object)->value());
-      return Smi::FromInt(string->length());
+      Handle<Object> string = object->IsJSValue()
+          ? Handle<Object>(Handle<JSValue>::cast(object)->value(), isolate())
+          : object;
+      return Smi::FromInt(String::cast(*string)->length());
     }
 
     // Use specialized code for getting prototype of functions.
     if (object->IsJSFunction() &&
         name->Equals(isolate()->heap()->prototype_string()) &&
         Handle<JSFunction>::cast(object)->should_have_prototype()) {
       Handle<Code> stub;
       if (state == UNINITIALIZED) {
         stub = pre_monomorphic_stub();
       } else if (state == PREMONOMORPHIC) {
@@ skipping 11 matching lines @@
       }
       return *Accessors::FunctionGetPrototype(Handle<JSFunction>::cast(object));
     }
   }
 
   // Check if the name is trivially convertible to an index and get
   // the element or char if so.
   uint32_t index;
   if (kind() == Code::KEYED_LOAD_IC && name->AsArrayIndex(&index)) {
     // Rewrite to the generic keyed load stub.
-    if (use_ic) set_target(*generic_stub());
+    if (FLAG_use_ic) set_target(*generic_stub());
     return Runtime::GetElementOrCharAtOrFail(isolate(), object, index);
   }
 
   if (object->IsJSObject()) {
     Handle<JSObject> receiver = Handle<JSObject>::cast(object);
     if (receiver->map()->is_deprecated()) {
-      use_ic = false;
       JSObject::MigrateInstance(receiver);
     }
   }
 
   // Named lookup in the object.
   LookupResult lookup(isolate());
   LookupForRead(object, name, &lookup);
 
   // If we did not find a property, check if we need to throw an exception.
   if (!lookup.IsFound()) {
     if (IsUndeclaredGlobal(object)) {
       return ReferenceError("not_defined", name);
     }
     LOG(isolate(), SuspectReadEvent(*name, *object));
   }
 
   // Update inline cache and stub cache.
-  if (use_ic) UpdateCaches(&lookup, state, object, name);
+  if (FLAG_use_ic) UpdateCaches(&lookup, state, object, name);
 
   PropertyAttributes attr;
   if (lookup.IsInterceptor() || lookup.IsHandler()) {
     // Get the property.
     Handle<Object> result =
         Object::GetProperty(object, object, &lookup, name, &attr);
     RETURN_IF_EMPTY_HANDLE(isolate(), result);
     // If the property is not present, check if we need to throw an
     // exception.
     if (attr == ABSENT && IsUndeclaredGlobal(object)) {
@@ skipping 284 matching lines @@
       UNREACHABLE();
       break;
   }
 }
 
 
 void LoadIC::UpdateCaches(LookupResult* lookup,
                           State state,
                           Handle<Object> object,
                           Handle<String> name) {
-  // TODO(verwaest): It would be nice to support loading fields from smis as
-  // well. For now just fail to update the cache.
   if (!object->IsHeapObject()) return;
 
   Handle<HeapObject> receiver = Handle<HeapObject>::cast(object);
 
   Handle<Code> code;
   if (state == UNINITIALIZED) {
     // This is the first time we execute this inline cache.
     // Set the target to the pre monomorphic stub to delay
     // setting the monomorphic state.
     code = pre_monomorphic_stub();
   } else if (!lookup->IsCacheable()) {
     // Bail out if the result is not cacheable.
     code = slow_stub();
-  } else if (object->IsString() &&
-             name->Equals(isolate()->heap()->length_string())) {
-    int length_index = String::kLengthOffset / kPointerSize;
-    if (target()->is_load_stub()) {
-      LoadFieldStub stub(true, length_index, Representation::Tagged());
-      code = stub.GetCode(isolate());
-    } else {
-      KeyedLoadFieldStub stub(true, length_index, Representation::Tagged());
-      code = stub.GetCode(isolate());
-    }
   } else if (!object->IsJSObject()) {
     // TODO(jkummerow): It would be nice to support non-JSObjects in
     // ComputeLoadHandler, then we wouldn't need to go generic here.
     code = slow_stub();
   } else {
     code = ComputeLoadHandler(lookup, Handle<JSObject>::cast(receiver), name);
     if (code.is_null()) code = slow_stub();
   }
 
   PatchCache(state, kNonStrictMode, receiver, name, code);
@@ skipping 64 matching lines @@
         CallOptimization call_optimization(function);
         if (call_optimization.is_simple_api_call() &&
             call_optimization.IsCompatibleReceiver(*receiver) &&
             FLAG_js_accessor_ics) {
           return isolate()->stub_cache()->ComputeLoadCallback(
               name, receiver, holder, call_optimization);
         }
         return isolate()->stub_cache()->ComputeLoadViaGetter(
             name, receiver, holder, function);
       } else if (receiver->IsJSArray() &&
-                 name->Equals(isolate()->heap()->length_string())) {
-        PropertyIndex lengthIndex = PropertyIndex::NewHeaderIndex(
-            JSArray::kLengthOffset / kPointerSize);
+          name->Equals(isolate()->heap()->length_string())) {
+        PropertyIndex lengthIndex =
+          PropertyIndex::NewHeaderIndex(JSArray::kLengthOffset / kPointerSize);
         return isolate()->stub_cache()->ComputeLoadField(
             name, receiver, holder, lengthIndex, Representation::Tagged());
       }
       // TODO(dcarney): Handle correctly.
       if (callback->IsDeclaredAccessorInfo()) break;
       ASSERT(callback->IsForeign());
       // No IC support for old-style native accessors.
       break;
     }
     case INTERCEPTOR:
@@ skipping 111 matching lines @@
   if (use_ic) {
     Handle<Code> stub = generic_stub();
     if (miss_mode != MISS_FORCE_GENERIC) {
       if (object->IsString() && key->IsNumber()) {
         if (state == UNINITIALIZED) {
           stub = string_stub();
         }
       } else if (object->IsJSObject()) {
         Handle<JSObject> receiver = Handle<JSObject>::cast(object);
         if (receiver->map()->is_deprecated()) {
-          use_ic = false;
           JSObject::MigrateInstance(receiver);
         }
 
         if (receiver->elements()->map() ==
             isolate()->heap()->non_strict_arguments_elements_map()) {
           stub = non_strict_arguments_stub();
         } else if (receiver->HasIndexedInterceptor()) {
           stub = indexed_interceptor_stub();
         } else if (!key->ToSmi()->IsFailure() &&
                    (target() != *non_strict_arguments_stub())) {
           stub = LoadElementStub(receiver);
         }
       }
     } else {
       TRACE_GENERIC_IC(isolate(), "KeyedLoadIC", "force generic");
     }
-    if (use_ic) {
-      ASSERT(!stub.is_null());
-      set_target(*stub);
-      TRACE_IC("KeyedLoadIC", key, state, target());
-    }
+    ASSERT(!stub.is_null());
+    set_target(*stub);
+    TRACE_IC("KeyedLoadIC", key, state, target());
   }
 
 
   return Runtime::GetObjectPropertyOrFail(isolate(), object, key);
 }
 
 
 Handle<Code> KeyedLoadIC::ComputeLoadHandler(LookupResult* lookup,
                                              Handle<JSObject> receiver,
                                              Handle<String> name) {
@@ skipping 143 matching lines @@
       name->Equals(isolate()->heap()->length_string())) {
     return TypeError("strict_read_only_property", object, name);
   }
 
   // Ignore other stores where the receiver is not a JSObject.
   // TODO(1475): Must check prototype chains of object wrappers.
   if (!object->IsJSObject()) return *value;
 
   Handle<JSObject> receiver = Handle<JSObject>::cast(object);
 
-  bool use_ic = FLAG_use_ic;
   if (receiver->map()->is_deprecated()) {
-    use_ic = false;
     JSObject::MigrateInstance(receiver);
   }
 
   // Check if the given name is an array index.
   uint32_t index;
   if (name->AsArrayIndex(&index)) {
     Handle<Object> result =
         JSObject::SetElement(receiver, index, value, NONE, strict_mode);
     RETURN_IF_EMPTY_HANDLE(isolate(), result);
     return *value;
   }
 
   // Observed objects are always modified through the runtime.
   if (FLAG_harmony_observation && receiver->map()->is_observed()) {
     return JSReceiver::SetPropertyOrFail(
         receiver, name, value, NONE, strict_mode, store_mode);
   }
 
   // Use specialized code for setting the length of arrays with fast
   // properties. Slow properties might indicate redefinition of the length
   // property. Note that when redefined using Object.freeze, it's possible
   // to have fast properties but a read-only length.
-  if (use_ic &&
+  if (FLAG_use_ic &&
       receiver->IsJSArray() &&
       name->Equals(isolate()->heap()->length_string()) &&
       Handle<JSArray>::cast(receiver)->AllowsSetElementsLength() &&
       receiver->HasFastProperties() &&
       !receiver->map()->is_frozen()) {
     Handle<Code> stub =
         StoreArrayLengthStub(kind(), strict_mode).GetCode(isolate());
     set_target(*stub);
     TRACE_IC("StoreIC", name, state, *stub);
     return JSReceiver::SetPropertyOrFail(
         receiver, name, value, NONE, strict_mode, store_mode);
   }
 
   if (receiver->IsJSGlobalProxy()) {
-    if (use_ic && kind() != Code::KEYED_STORE_IC) {
+    if (FLAG_use_ic && kind() != Code::KEYED_STORE_IC) {
       // Generate a generic stub that goes to the runtime when we see a global
       // proxy as receiver.
       Handle<Code> stub = (strict_mode == kStrictMode)
           ? global_proxy_stub_strict()
           : global_proxy_stub();
       set_target(*stub);
       TRACE_IC("StoreIC", name, state, *stub);
     }
     return JSReceiver::SetPropertyOrFail(
         receiver, name, value, NONE, strict_mode, store_mode);
   }
 
   LookupResult lookup(isolate());
   bool can_store = LookupForWrite(receiver, name, value, &lookup, &state);
   if (!can_store &&
       strict_mode == kStrictMode &&
       !(lookup.IsProperty() && lookup.IsReadOnly()) &&
       IsUndeclaredGlobal(object)) {
     // Strict mode doesn't allow setting non-existent global property.
     return ReferenceError("not_defined", name);
   }
-  if (use_ic) {
+  if (FLAG_use_ic) {
     if (state == UNINITIALIZED) {
       Handle<Code> stub = (strict_mode == kStrictMode)
           ? pre_monomorphic_stub_strict()
           : pre_monomorphic_stub();
       set_target(*stub);
       TRACE_IC("StoreIC", name, state, *stub);
     } else if (can_store) {
       UpdateCaches(&lookup, state, strict_mode, receiver, name, value);
     } else if (!name->IsCacheable(isolate()) ||
                lookup.IsNormal() ||
@@ skipping 1381 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal