} else if (key->IsSmi() && (target() != *non_strict_arguments_stub())) {
stub = ComputeStub(receiver, LOAD, kNonStrictMode, stub);
}
+ // If the IC is being replaced by the generic stub, loads from
+ // FAST_DOUBLE_ELEMENTS arrays will cause unboxing in Crankshafted
+ // code. To prevent these expensive allocations, proactively promote
+ // arrays to FAST_ELEMENTS ElementKinds.
+ if (*stub == *generic_stub()) {
+ if (receiver->HasFastDoubleElements()) {
+ MaybeObject* maybe_object =
+ receiver->TransitionElementsKind(FAST_ELEMENTS);
+ if (maybe_object->IsFailure()) return maybe_object;
+ }
+ }
}
} else {
TRACE_GENERIC_IC("KeyedLoadIC", "force generic");
// If value is the hole do the general lookup.
}
}
- } else if (FLAG_smi_only_arrays && args.at<Object>(1)->IsSmi()) {
+ } else if (args.at<Object>(1)->IsSmi()) {
+ // Getting properties from FAST_DOUBLE_ELEMENTS arrays causes boxing. To
+ // proactively avoid excessive boxing, transition FAST_DOUBLE_ELEMENTS
+ // arrays to FAST_ELEMENTS if they are accessed via this function, which
+ // is called by the KeyedLoadIC::GenericStub.
+ Handle<JSObject> js_object(args.at<JSObject>(0));
+ if (js_object->HasFastDoubleElements()) {
+ MaybeObject* maybe_object =
+ js_object->TransitionElementsKind(FAST_ELEMENTS);
+ if (maybe_object->IsFailure()) return maybe_object;
+ }
+
// JSObject without a string key. If the key is a Smi, check for a
// definite out-of-bounds access to elements, which is a strong indicator
// that subsequent accesses will also call the runtime. Proactively
// transition elements to FAST_ELEMENTS to avoid excessive boxing of
// doubles for those future calls in the case that the elements would
// become FAST_DOUBLE_ELEMENTS.
- Handle<JSObject> js_object(args.at<JSObject>(0));
ElementsKind elements_kind = js_object->GetElementsKind();
if (elements_kind == FAST_SMI_ONLY_ELEMENTS ||
elements_kind == FAST_DOUBLE_ELEMENTS) {