Minor cleanup IC keyed access handling.

src/ic/ic.cc

Index: src/ic/ic.cc
diff --git a/src/ic/ic.cc b/src/ic/ic.cc
index 7d572ee4819263c6368c0e83c458aa6d072c7e46..a6b45e9912f8eef13d114a78ac9719d3b50c9c1e 100644
--- a/src/ic/ic.cc
+++ b/src/ic/ic.cc
@@ -1402,9 +1402,7 @@ MaybeHandle<Object> KeyedLoadIC::Load(Handle<Object> object,
   } else if (FLAG_use_ic && !object->IsAccessCheckNeeded()) {
     if (object->IsJSObject() || (object->IsString() && key->IsNumber())) {
       Handle<HeapObject> receiver = Handle<HeapObject>::cast(object);
-      if (object->IsString() || !Object::ToSmi(isolate(), key).is_null()) {
-        stub = LoadElementStub(receiver);
-      }
+      if (object->IsString() || key->IsSmi()) stub = LoadElementStub(receiver);
     }
   }
 
@@ -1994,25 +1992,24 @@ Handle<Map> KeyedStoreIC::ComputeTransitionedMap(
 }
 
 
-bool IsOutOfBoundsAccess(Handle<JSObject> receiver, int index) {
+bool IsOutOfBoundsAccess(Handle<JSObject> receiver, uint32_t index) {
+  uint32_t length = 0;
   if (receiver->IsJSArray()) {
-    return JSArray::cast(*receiver)->length()->IsSmi() &&
-           index >= Smi::cast(JSArray::cast(*receiver)->length())->value();
+    JSArray::cast(*receiver)->length()->ToArrayLength(&length);
+  } else {
+    length = static_cast<uint32_t>(receiver->elements()->length());
   }
-  return index >= receiver->elements()->length();
+  return index >= length;
 }
 
 
-KeyedAccessStoreMode KeyedStoreIC::GetStoreMode(Handle<JSObject> receiver,
-                                                Handle<Object> key,
-                                                Handle<Object> value) {
-  Handle<Smi> smi_key = Object::ToSmi(isolate(), key).ToHandleChecked();
-  int index = smi_key->value();
+static KeyedAccessStoreMode GetStoreMode(Handle<JSObject> receiver,
+                                         uint32_t index, Handle<Object> value) {
   bool oob_access = IsOutOfBoundsAccess(receiver, index);
   // Don't consider this a growing store if the store would send the receiver to
   // dictionary mode.
   bool allow_growth = receiver->IsJSArray() && oob_access &&
-                      !receiver->WouldConvertToSlowElements(key);
+                      !receiver->WouldConvertToSlowElements(index);
   if (allow_growth) {
     // Handle growing array in stub if necessary.
     if (receiver->HasFastSmiElements()) {
@@ -2145,18 +2142,19 @@ MaybeHandle<Object> KeyedStoreIC::Store(Handle<Object> object,
   if (use_ic) {
     if (object->IsJSObject()) {
       Handle<JSObject> receiver = Handle<JSObject>::cast(object);
-      bool key_is_smi_like = !Object::ToSmi(isolate(), key).is_null();
       if (receiver->elements()->map() ==
               isolate()->heap()->sloppy_arguments_elements_map() &&
           !is_sloppy(language_mode())) {
         TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "arguments receiver");
-      } else if (key_is_smi_like) {
+      } else if (key->IsSmi() && Smi::cast(*key)->value() >= 0) {
+        uint32_t index = static_cast<uint32_t>(Smi::cast(*key)->value());
         // We should go generic if receiver isn't a dictionary, but our
         // prototype chain does have dictionary elements. This ensures that
         // other non-dictionary receivers in the polymorphic case benefit
         // from fast path keyed stores.
-        if (!(receiver->map()->DictionaryElementsInPrototypeChainOnly())) {
-          KeyedAccessStoreMode store_mode = GetStoreMode(receiver, key, value);
+        if (!receiver->map()->DictionaryElementsInPrototypeChainOnly()) {
+          KeyedAccessStoreMode store_mode =
+              GetStoreMode(receiver, index, value);
           stub = StoreElementStub(receiver, store_mode);
         } else {
           TRACE_GENERIC_IC(isolate(), "KeyedStoreIC", "dictionary prototype");