diff -r 12807399b953 -r b3f0aaee735a src/ObjectVisitor.h
--- a/src/ObjectVisitor.h	Sun Aug 05 01:28:12 2012 -0700
+++ b/src/ObjectVisitor.h	Sun Aug 05 01:45:37 2012 -0700
@@ -58,11 +58,11 @@
         Object **ptr = reinterpret_cast<Object **>(array + 1);
         for (unsigned i = 0; i < length; i++)
             this->visit(ptr + i);
-        return FixedArray::SizeFor(length);
+        return array->objSize();
     }
 
     size_t iterateByteArray(ByteArray *array) {
-        return ByteArray::SizeFor(array->length());
+        return array->objSize();
     }
 
     size_t iterateCode(Object *obj) {
@@ -110,7 +110,7 @@
     }
 
     size_t iterateString(Object *obj) {
-        return String::SizeFor(String::cast(obj)->length());
+        return String::cast(obj)->objSize();
     }
 
     size_t iterateArray(Array *array, ArrayMap *map) {
@@ -134,18 +134,18 @@
         EnvironmentSlotDescriptor *desc = env->slots();
         for (unsigned i = 0; i < length; i++)
             this->visit(desc->type.addr());
-        return env->size();
+        return env->objSize();
     }
 
     size_t iterateEnvironmentMap(EnvironmentMap *map) {
         visitField(map, EnvironmentMap::offsetOfSlots());
-        return map->size();
+        return map->objSize();
     }
 
     size_t iterateStructMap(StructMap *map) {
         visitField(map, StructMap::offsetOfType());
         visitField(map, StructMap::offsetOfComposed());
-        return map->size();
+        return map->objSize();
     }
 
     size_t iterateEnvironment(Environment *env) {
@@ -154,7 +154,7 @@
         unsigned noffsets = map->traceOffsetCount();
         for (unsigned i = 0; i < noffsets; i++)
             visitField(env, Environment::offsetOfSlotOffset(offsets[i]));
-        return env->size();
+        return env->objSize();
     }
 
     size_t iterateStruct(Struct *obj) {
@@ -163,16 +163,16 @@
         unsigned noffsets = map->traceOffsetCount();
         for (unsigned i = 0; i < noffsets; i++)
             visitField(obj, Struct::offsetOfSlotOffset(offsets[i]));
-        return obj->size();
+        return obj->objSize();
     }
 
-  public:
-    size_t iterate(Object *obj) {
+  private:
+    size_t iterateObject(Object *obj) {
         visitField(obj, Object::offsetOfMap());
         return iterate(obj, obj->map());
     }
 
-    size_t iterate(Object *obj, Map *map) {
+    size_t iterateObject(Object *obj, Map *map) {
         switch (map->kind()) {
           case MapKind_Type:
             return iterateType(obj);
@@ -230,20 +230,29 @@
             return sizeof(Map);
         }
     }
+
+  public:
+    size_t iterate(Object *obj) {
+        return Align(iterateObject(obj), kObjectAlignment);
+    }
+
+    size_t iterate(Object *obj, Map *map) {
+        return Align(iterateObject(obj, map), kObjectAlignment);
+    }
 };
 
 static inline size_t
-SizeOfObject(Object *obj, Map *map)
+SizeOfObjectRaw(Object *obj, Map *map)
 {
     switch (map->kind()) {
       case MapKind_Type:
         return sizeof(Type);
 
       case MapKind_FixedArray:
-        return FixedArray::SizeFor(FixedArray::cast(obj)->length());
+        return FixedArray::cast(obj)->objSize();
 
       case MapKind_ByteArray:
-        return ByteArray::SizeFor(ByteArray::cast(obj)->length());
+        return ByteArray::cast(obj)->objSize();
 
       case MapKind_Code:
         return sizeof(Code);
@@ -261,7 +270,7 @@
         return sizeof(Function);
 
       case MapKind_String:
-        return String::SizeFor(String::cast(obj)->length());
+        return String::cast(obj)->objSize();
 
       case MapKind_Native:
         return sizeof(Native);
@@ -270,22 +279,22 @@
         return Align(Array::SizeOf(Array::cast(obj)), kObjectAlignment);
 
       case MapKind_Struct:
-        return Struct::cast(obj)->size();
+        return Struct::cast(obj)->objSize();
 
       case MapKind_EnvironmentSlotDescriptorArray:
-        return EnvironmentSlotDescriptorArray::cast(obj)->size();
+        return EnvironmentSlotDescriptorArray::cast(obj)->objSize();
 
       case MapKind_Environment:
-        return Environment::cast(obj)->size();
+        return Environment::cast(obj)->objSize();
 
       case MapKind_MetaArray:
         return sizeof(ArrayMap);
 
       case MapKind_MetaEnvironment:
-        return EnvironmentMap::cast(obj)->size();
+        return EnvironmentMap::cast(obj)->objSize();
 
       case MapKind_MetaStruct:
-        return StructMap::cast(obj)->size();
+        return StructMap::cast(obj)->objSize();
 
       case MapKind_FreeRegion:
         return *reinterpret_cast<size_t *>(reinterpret_cast<Address>(obj + 1));
@@ -296,6 +305,12 @@
     }
 }
 
+static inline size_t
+SizeOfObject(Object *obj, Map *map)
+{
+    return Align(SizeOfObjectRaw(obj, map), kObjectAlignment);
+}
+
 class ObjectSizeEvaluator
 {
   public: