Introduce FieldIndex to unify and abstract property/field offset

src/runtime.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stdlib.h>
 #include <limits>
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
@@ skipping 2535 matching lines @@
         JSReceiver::SetProperty(global, name, value, attributes, SLOPPY));
     return *value;
   }
 
   // Set the value, but only if we're assigning the initial value to a
   // constant. For now, we determine this by checking if the
   // current value is the hole.
   // Strict mode handling not needed (const is disallowed in strict mode).
   if (lookup.IsField()) {
     FixedArray* properties = global->properties();
-    int index = lookup.GetFieldIndex().field_index();
+    int index = lookup.GetFieldIndex().property_index();
     if (properties->get(index)->IsTheHole() || !lookup.IsReadOnly()) {
       properties->set(index, *value);
     }
   } else if (lookup.IsNormal()) {
     if (global->GetNormalizedProperty(&lookup)->IsTheHole() ||
         !lookup.IsReadOnly()) {
       HandleScope scope(isolate);
       JSObject::SetNormalizedProperty(Handle<JSObject>(global), &lookup, value);
     }
   } else {
@@ skipping 68 matching lines @@
     // This is the property that was introduced by the const declaration.
     // Set it if it hasn't been set before.  NOTE: We cannot use
     // GetProperty() to get the current value as it 'unholes' the value.
     LookupResult lookup(isolate);
     object->LookupOwnRealNamedProperty(name, &lookup);
     ASSERT(lookup.IsFound());  // the property was declared
     ASSERT(lookup.IsReadOnly());  // and it was declared as read-only
 
     if (lookup.IsField()) {
       FixedArray* properties = object->properties();
-      int index = lookup.GetFieldIndex().field_index();
-      if (properties->get(index)->IsTheHole()) {
-        properties->set(index, *value);
+      FieldIndex index = lookup.GetFieldIndex();
+      ASSERT(!index.is_inobject());
+      if (properties->get(index.property_index())->IsTheHole()) {
+        properties->set(index.property_index(), *value);
       }
     } else if (lookup.IsNormal()) {
       if (object->GetNormalizedProperty(&lookup)->IsTheHole()) {
         JSObject::SetNormalizedProperty(object, &lookup, value);
       }
     } else {
       // We should not reach here. Any real, named property should be
       // either a field or a dictionary slot.
       UNREACHABLE();
     }
@@ skipping 2386 matching lines @@
     if (!receiver_obj->IsJSGlobalProxy() &&
         !receiver_obj->IsAccessCheckNeeded() &&
         key_obj->IsName()) {
       DisallowHeapAllocation no_allocation;
       Handle<JSObject> receiver = Handle<JSObject>::cast(receiver_obj);
       Handle<Name> key = Handle<Name>::cast(key_obj);
       if (receiver->HasFastProperties()) {
         // Attempt to use lookup cache.
         Handle<Map> receiver_map(receiver->map(), isolate);
         KeyedLookupCache* keyed_lookup_cache = isolate->keyed_lookup_cache();
-        int offset = keyed_lookup_cache->Lookup(receiver_map, key);
-        if (offset != -1) {
+        int index = keyed_lookup_cache->Lookup(receiver_map, key);
+        if (index != -1) {
           // Doubles are not cached, so raw read the value.
-          Object* value = receiver->RawFastPropertyAt(offset);
+          Object* value = receiver->RawFastPropertyAt(
+              FieldIndex::ForKeyedLookupCacheIndex(*receiver_map, index));
           return value->IsTheHole()
               ? isolate->heap()->undefined_value()
               : value;
         }
         // Lookup cache miss.  Perform lookup and update the cache if
         // appropriate.
         LookupResult result(isolate);
         receiver->LookupOwn(key, &result);
         if (result.IsField()) {
-          int offset = result.GetFieldIndex().field_index();
+          FieldIndex field_index = result.GetFieldIndex();
           // Do not track double fields in the keyed lookup cache. Reading
           // double values requires boxing.
           if (!result.representation().IsDouble()) {
-            keyed_lookup_cache->Update(receiver_map, key, offset);
+            keyed_lookup_cache->Update(receiver_map, key,
+                field_index.GetKeyedLookupCacheIndex());
           }
           AllowHeapAllocation allow_allocation;
-          return *JSObject::FastPropertyAt(
-              receiver, result.representation(), offset);
+          return *JSObject::FastPropertyAt(receiver, result.representation(),
+                                           field_index);
         }
       } else {
         // Attempt dictionary lookup.
         NameDictionary* dictionary = receiver->property_dictionary();
         int entry = dictionary->FindEntry(key);
         if ((entry != NameDictionary::kNotFound) &&
             (dictionary->DetailsAt(entry).type() == NORMAL)) {
           Object* value = dictionary->ValueAt(entry);
           if (!receiver->IsGlobalObject()) return value;
           value = PropertyCell::cast(value)->value();
@@ skipping 5681 matching lines @@
   Handle<Object> value = isolate->factory()->undefined_value();
   if  (!result->IsFound()) return value;
   switch (result->type()) {
     case NORMAL:
       value = JSObject::GetNormalizedProperty(
           handle(result->holder(), isolate), result);
       break;
     case FIELD:
       value = JSObject::FastPropertyAt(handle(result->holder(), isolate),
                                        result->representation(),
-                                       result->GetFieldIndex().field_index());
+                                       result->GetFieldIndex());
       break;
     case CONSTANT:
       return handle(result->GetConstant(), isolate);
     case CALLBACKS: {
       Handle<Object> structure(result->GetCallbackObject(), isolate);
       ASSERT(!structure->IsForeign());
       if (structure->IsAccessorInfo()) {
         MaybeHandle<Object> obj = JSObject::GetPropertyWithCallback(
             receiver, name, handle(result->holder(), isolate), structure);
         if (!obj.ToHandle(&value)) {
@@ skipping 3748 matching lines @@
   isolate->heap()->NotifyContextDisposed();
   return isolate->heap()->undefined_value();
 }
 
 
 RUNTIME_FUNCTION(Runtime_LoadMutableDouble) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 2);
   CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
   CONVERT_ARG_HANDLE_CHECKED(Smi, index, 1);
-  int idx = index->value() >> 1;
-  int inobject_properties = object->map()->inobject_properties();
-  if (idx < 0) {
-    idx = -idx + inobject_properties - 1;
-  }
-  int max_idx = object->properties()->length() + inobject_properties;
-  RUNTIME_ASSERT(idx < max_idx);
-  Handle<Object> raw_value(object->RawFastPropertyAt(idx), isolate);
+  RUNTIME_ASSERT((index->value() & 1) == 1);
+  FieldIndex field_index =
+      FieldIndex::ForLoadByFieldIndex(object->map(), index->value() >> 1);
+  int max_idx = field_index.is_inobject()
+      ? object->map()->inobject_properties()
+      : object->properties()->length();
+  RUNTIME_ASSERT(field_index.property_index() < max_idx);
+  Handle<Object> raw_value(object->RawFastPropertyAt(field_index), isolate);
   RUNTIME_ASSERT(raw_value->IsNumber() || raw_value->IsUninitialized());
   return *Object::NewStorageFor(isolate, raw_value, Representation::Double());
 }
 
 
 RUNTIME_FUNCTION(Runtime_TryMigrateInstance) {
   HandleScope scope(isolate);
   ASSERT(args.length() == 1);
   CONVERT_ARG_HANDLE_CHECKED(Object, object, 0);
   if (!object->IsJSObject()) return Smi::FromInt(0);
@@ skipping 572 matching lines @@
   }
   return NULL;
 }
 
 
 const Runtime::Function* Runtime::FunctionForId(Runtime::FunctionId id) {
   return &(kIntrinsicFunctions[static_cast<int>(id)]);
 }
 
 } }  // namespace v8::internal