Install a generic handler whenever we fail to update the IC.

src/ic.cc

Index: src/ic.cc
diff --git a/src/ic.cc b/src/ic.cc
index 77e01967f6a80fe405c3a12f7043d2da88b66d88..029aafdcf714cb08d71721494717afc566ad78a2 100644
--- a/src/ic.cc
+++ b/src/ic.cc
@@ -936,15 +936,7 @@ MaybeObject* LoadIC::Load(State state,
   }
 
   // Update inline cache and stub cache.
-  if (FLAG_use_ic) {
-    if (!object->IsJSObject()) {
-      // TODO(jkummerow): It would be nice to support non-JSObjects in
-      // UpdateCaches, then we wouldn't need to go generic here.
-      set_target(*generic_stub());
-    } else {
-      UpdateCaches(&lookup, state, object, name);
-    }
-  }
+  if (FLAG_use_ic) UpdateCaches(&lookup, state, object, name);
 
   PropertyAttributes attr;
   if (lookup.IsInterceptor() || lookup.IsHandler()) {
@@ -1204,11 +1196,17 @@ void LoadIC::UpdateCaches(LookupResult* lookup,
                           Handle<Object> object,
                           Handle<String> name) {
   // Bail out if the result is not cacheable.
-  if (!lookup->IsCacheable()) return;
+  if (!lookup->IsCacheable()) {
+    set_target(*generic_stub());
+    return;
+  }
 
-  // Loading properties from values is not common, so don't try to
-  // deal with non-JS objects here.
-  if (!object->IsJSObject()) return;
+  // TODO(jkummerow): It would be nice to support non-JSObjects in
+  // UpdateCaches, then we wouldn't need to go generic here.
+  if (!object->IsJSObject()) {
+    set_target(*generic_stub());
+    return;
+  }
 
   Handle<JSObject> receiver = Handle<JSObject>::cast(object);
   Handle<Code> code;
@@ -1219,7 +1217,10 @@ void LoadIC::UpdateCaches(LookupResult* lookup,
     code = pre_monomorphic_stub();
   } else {
     code = ComputeLoadHandler(lookup, receiver, name);
-    if (code.is_null()) return;
+    if (code.is_null()) {
+      set_target(*generic_stub());
+      return;
+    }
   }
 
   PatchCache(state, kNonStrictMode, receiver, name, code);
@@ -1640,6 +1641,12 @@ MaybeObject* StoreIC::Store(State state,
              IsUndeclaredGlobal(object)) {
     // Strict mode doesn't allow setting non-existent global property.
     return ReferenceError("not_defined", name);
+  } else if (FLAG_use_ic &&
+             (lookup.IsNormal() ||
+              (lookup.IsField() && lookup.CanHoldValue(value)))) {
+    Handle<Code> stub = strict_mode == kStrictMode
+        ? generic_stub_strict() : generic_stub();
+    set_target(*stub);
   }
 
   // Set the property.
@@ -1660,9 +1667,14 @@ void StoreIC::UpdateCaches(LookupResult* lookup,
   // These are not cacheable, so we never see such LookupResults here.
   ASSERT(!lookup->IsHandler());
 
-  Handle<Code> code =
-      ComputeStoreMonomorphic(lookup, strict_mode, receiver, name);
-  if (code.is_null()) return;
+  Handle<Code> code = ComputeStoreMonomorphic(
+      lookup, strict_mode, receiver, name);
+  if (code.is_null()) {
+    Handle<Code> stub = strict_mode == kStrictMode
+        ? generic_stub_strict() : generic_stub();
+    set_target(*stub);
+    return;
+  }
 
   PatchCache(state, strict_mode, receiver, name, code);
   TRACE_IC("StoreIC", name, state, target());