Only update the stub cache tables with monomorphic stubs used by...

src/ic.cc

 // Copyright 2006-2009 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 369 matching lines @@
     const int argc = this->target()->arguments_count();
     StackFrameLocator locator;
     JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
     int index = frame->ComputeExpressionsCount() - (argc + 1);
     frame->SetExpression(index, *target);
   }
 
   return *delegate;
 }
 
+
 void CallICBase::ReceiverToObject(Handle<Object> object) {
   HandleScope scope;
   Handle<Object> receiver(object);
 
   // Change the receiver to the result of calling ToObject on it.
   const int argc = this->target()->arguments_count();
   StackFrameLocator locator;
   JavaScriptFrame* frame = locator.FindJavaScriptFrame(0);
   int index = frame->ComputeExpressionsCount() - (argc + 1);
   frame->SetExpression(index, *Factory::ToObject(object));
@@ skipping 181 matching lines @@
   // If we're unable to compute the stub (not enough memory left), we
   // simply avoid updating the caches.
   if (code == NULL || code->IsFailure()) return;
 
   // Patch the call site depending on the state of the cache.
   if (state == UNINITIALIZED ||
       state == PREMONOMORPHIC ||
       state == MONOMORPHIC ||
       state == MONOMORPHIC_PROTOTYPE_FAILURE) {
     set_target(Code::cast(code));
+  } else if (state == MEGAMORPHIC) {
+    // Update the stub cache.
+    StubCache::Set(*name, GetCodeCacheMapForObject(*object), Code::cast(code));
   }
 
 #ifdef DEBUG
   TraceIC(kind_ == Code::CALL_IC ? "CallIC" : "KeyedCallIC",
       name, state, target(), in_loop ? " (in-loop)" : "");
 #endif
 }
 
 
 Object* KeyedCallIC::LoadFunction(State state,
@@ skipping 56 matching lines @@
 #endif
       Map* map = HeapObject::cast(*object)->map();
       if (object->IsString()) {
         const int offset = String::kLengthOffset;
         PatchInlinedLoad(address(), map, offset);
       }
 
       Code* target = NULL;
       target = Builtins::builtin(Builtins::LoadIC_StringLength);
       set_target(target);
-      StubCache::Set(*name, map, target);
       return Smi::FromInt(String::cast(*object)->length());
     }
 
     // Use specialized code for getting the length of arrays.
     if (object->IsJSArray() && name->Equals(Heap::length_symbol())) {
 #ifdef DEBUG
       if (FLAG_trace_ic) PrintF("[LoadIC : +#length /array]\n");
 #endif
       Map* map = HeapObject::cast(*object)->map();
       const int offset = JSArray::kLengthOffset;
       PatchInlinedLoad(address(), map, offset);
 
       Code* target = Builtins::builtin(Builtins::LoadIC_ArrayLength);
       set_target(target);
-      StubCache::Set(*name, map, target);
       return JSArray::cast(*object)->length();
     }
 
     // Use specialized code for getting prototype of functions.
     if (object->IsJSFunction() && name->Equals(Heap::prototype_symbol()) &&
         JSFunction::cast(*object)->should_have_prototype()) {
 #ifdef DEBUG
       if (FLAG_trace_ic) PrintF("[LoadIC : +#prototype /function]\n");
 #endif
       Code* target = Builtins::builtin(Builtins::LoadIC_FunctionPrototype);
       set_target(target);
-      StubCache::Set(*name, HeapObject::cast(*object)->map(), target);
       return Accessors::FunctionGetPrototype(*object, 0);
     }
   }
 
   // Check if the name is trivially convertible to an index and get
   // the element if so.
   uint32_t index;
   if (name->AsArrayIndex(&index)) return object->GetElement(index);
 
   // Named lookup in the object.
@@ skipping 135 matching lines @@
   // If we're unable to compute the stub (not enough memory left), we
   // simply avoid updating the caches.
   if (code == NULL || code->IsFailure()) return;
 
   // Patch the call site depending on the state of the cache.
   if (state == UNINITIALIZED || state == PREMONOMORPHIC ||
       state == MONOMORPHIC_PROTOTYPE_FAILURE) {
     set_target(Code::cast(code));
   } else if (state == MONOMORPHIC) {
     set_target(megamorphic_stub());
+  } else if (state == MEGAMORPHIC) {
+    // Update the stub cache.
+    StubCache::Set(*name, GetCodeCacheMapForObject(*object), Code::cast(code));
   }
 
 #ifdef DEBUG
   TraceIC("LoadIC", name, state, target());
 #endif
 }
 
 
 Object* KeyedLoadIC::Load(State state,
                           Handle<Object> object,
@@ skipping 243 matching lines @@
 
   // Check if the given name is an array index.
   uint32_t index;
   if (name->AsArrayIndex(&index)) {
     HandleScope scope;
     Handle<Object> result = SetElement(receiver, index, value);
     if (result.is_null()) return Failure::Exception();
     return *value;
   }
 
-
   // Use specialized code for setting the length of arrays.
   if (receiver->IsJSArray()
       && name->Equals(Heap::length_symbol())
       && receiver->AllowsSetElementsLength()) {
 #ifdef DEBUG
     if (FLAG_trace_ic) PrintF("[StoreIC : +#length /array]\n");
 #endif
     Code* target = Builtins::builtin(Builtins::StoreIC_ArrayLength);
     set_target(target);
-    StubCache::Set(*name, HeapObject::cast(*object)->map(), target);
     return receiver->SetProperty(*name, *value, NONE);
   }
 
   // Lookup the property locally in the receiver.
   if (FLAG_use_ic && !receiver->IsJSGlobalProxy()) {
     LookupResult lookup;
     if (LookupForWrite(*receiver, *name, &lookup)) {
       UpdateCaches(&lookup, state, receiver, name, value);
     }
   }
@@ skipping 67 matching lines @@
   }
 
   // If we're unable to compute the stub (not enough memory left), we
   // simply avoid updating the caches.
   if (code == NULL || code->IsFailure()) return;
 
   // Patch the call site depending on the state of the cache.
   if (state == UNINITIALIZED || state == MONOMORPHIC_PROTOTYPE_FAILURE) {
     set_target(Code::cast(code));
   } else if (state == MONOMORPHIC) {
-    // Only move to mega morphic if the target changes.
+    // Only move to megamorphic if the target changes.
     if (target() != Code::cast(code)) set_target(megamorphic_stub());
+  } else if (state == MEGAMORPHIC) {
+    // Update the stub cache.
+    StubCache::Set(*name, receiver->map(), Code::cast(code));
   }
 
 #ifdef DEBUG
   TraceIC("StoreIC", name, state, target());
 #endif
 }
 
 
 Object* KeyedStoreIC::Store(State state,
                             Handle<Object> object,
@@ skipping 367 matching lines @@
 #undef ADDR
 };
 
 
 Address IC::AddressFromUtilityId(IC::UtilityId id) {
   return IC_utilities[id];
 }
 
 
 } }  // namespace v8::internal