Track representations of fields

src/property.h

Index: src/property.h
diff --git a/src/property.h b/src/property.h
index bbba8aea60d89f432c3ca4eb52b86726e56baf07..229241948a8c4ee0dc253e199bdbd1710fdb8159 100644
--- a/src/property.h
+++ b/src/property.h
@@ -65,7 +65,8 @@ class Descriptor BASE_EMBEDDED {
 #endif
 
   void SetEnumerationIndex(int index) {
-    details_ = PropertyDetails(details_.attributes(), details_.type(), index);
+    details_ = PropertyDetails(details_.attributes(), details_.type(),
+                               details_.representation(), index);
   }
 
   void SetSortedKeyIndex(int index) { details_ = details_.set_pointer(index); }
@@ -93,10 +94,11 @@ class Descriptor BASE_EMBEDDED {
              Object* value,
              PropertyAttributes attributes,
              PropertyType type,
+             Representation representation,
              int index)
       : key_(key),
         value_(value),
-        details_(attributes, type, index) { }
+        details_(attributes, type, representation, index) { }
 
   friend class DescriptorArray;
 };
@@ -107,8 +109,10 @@ class FieldDescriptor: public Descriptor {
   FieldDescriptor(Name* key,
                   int field_index,
                   PropertyAttributes attributes,
+                  Representation representation,
                   int index = 0)
-      : Descriptor(key, Smi::FromInt(field_index), attributes, FIELD, index) {}
+      : Descriptor(key, Smi::FromInt(field_index), attributes,
+                   FIELD, representation, index) {}
 };
 
 
@@ -118,7 +122,8 @@ class ConstantFunctionDescriptor: public Descriptor {
                              JSFunction* function,
                              PropertyAttributes attributes,
                              int index)
-      : Descriptor(key, function, attributes, CONSTANT_FUNCTION, index) {}
+      : Descriptor(key, function, attributes,
+                   CONSTANT_FUNCTION, Representation::Tagged(), index) {}
 };
 
 
@@ -128,7 +133,8 @@ class CallbacksDescriptor:  public Descriptor {
                       Object* foreign,
                       PropertyAttributes attributes,
                       int index = 0)
-      : Descriptor(key, foreign, attributes, CALLBACKS, index) {}
+      : Descriptor(key, foreign, attributes, CALLBACKS,
+                   Representation::Tagged(), index) {}
 };
 
 
@@ -190,7 +196,7 @@ class LookupResult BASE_EMBEDDED {
         lookup_type_(NOT_FOUND),
         holder_(NULL),
         cacheable_(true),
-        details_(NONE, NONEXISTENT) {
+        details_(NONE, NONEXISTENT, Representation::None()) {
     isolate->SetTopLookupResult(this);
   }
 
@@ -208,9 +214,13 @@ class LookupResult BASE_EMBEDDED {
     number_ = number;
   }
 
+  bool CanHoldValue(Handle<Object> value) {
+    return value->FitsRepresentation(details_.representation());
+  }
+
   void TransitionResult(JSObject* holder, int number) {
     lookup_type_ = TRANSITION_TYPE;
-    details_ = PropertyDetails(NONE, TRANSITION);
+    details_ = PropertyDetails(NONE, TRANSITION, Representation::None());
     holder_ = holder;
     number_ = number;
   }
@@ -225,19 +235,19 @@ class LookupResult BASE_EMBEDDED {
   void HandlerResult(JSProxy* proxy) {
     lookup_type_ = HANDLER_TYPE;
     holder_ = proxy;
-    details_ = PropertyDetails(NONE, HANDLER);
+    details_ = PropertyDetails(NONE, HANDLER, Representation::None());
     cacheable_ = false;
   }
 
   void InterceptorResult(JSObject* holder) {
     lookup_type_ = INTERCEPTOR_TYPE;
     holder_ = holder;
-    details_ = PropertyDetails(NONE, INTERCEPTOR);
+    details_ = PropertyDetails(NONE, INTERCEPTOR, Representation::None());
   }
 
   void NotFound() {
     lookup_type_ = NOT_FOUND;
-    details_ = PropertyDetails(NONE, NONEXISTENT);
+    details_ = PropertyDetails(NONE, NONEXISTENT, Representation::None());
     holder_ = NULL;
   }
 
@@ -256,6 +266,11 @@ class LookupResult BASE_EMBEDDED {
     return details_.type();
   }
 
+  Representation representation() {
+    ASSERT(IsFound());
+    return details_.representation();
+  }
+
   PropertyAttributes GetAttributes() {
     ASSERT(!IsTransition());
     ASSERT(IsFound());