Calls to HCheckFunction can be eliminated if the value is an HConstant.

src/objects.cc

 // Copyright 2013 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 15881 matching lines @@
 void PropertyCell::set_type(Type* type, WriteBarrierMode ignored) {
   ASSERT(IsPropertyCell());
   set_type_raw(type, ignored);
 }
 
 
 Type* PropertyCell::UpdateType(Handle<PropertyCell> cell,
                                Handle<Object> value) {
   Isolate* isolate = cell->GetIsolate();
   Handle<Type> old_type(cell->type(), isolate);
-  Handle<Type> new_type((value->IsSmi() || value->IsUndefined())
+  Handle<Type> new_type((value->IsSmi() || value->IsJSFunction() ||
+                         value->IsUndefined())
                         ? Type::Constant(value, isolate)
                         : Type::Any(), isolate);
 
   if (new_type->Is(old_type)) {
     return *old_type;
   }
 
   cell->dependent_code()->DeoptimizeDependentCodeGroup(
       isolate, DependentCode::kPropertyCellChangedGroup);
 
@@ skipping 35 matching lines @@
 
 void PropertyCell::AddDependentCode(Handle<Code> code) {
   Handle<DependentCode> codes = DependentCode::Insert(
       Handle<DependentCode>(dependent_code()),
       DependentCode::kPropertyCellChangedGroup, code);
   if (*codes != dependent_code()) set_dependent_code(*codes);
 }
 
 
 } }  // namespace v8::internal