Add support for keyed-call on arrays of fast elements

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 7c42a3bcd63c0eb952d133a2c4e64863e5be2056..371ecaef126a65aab926c194ea6279745ad8b8f4 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -2378,7 +2378,7 @@ HGraphBuilder::JSArrayBuilder::JSArrayBuilder(HGraphBuilder* builder,
 
 
 HValue* HGraphBuilder::JSArrayBuilder::EmitMapCode() {
-  if (kind_ == GetInitialFastElementsKind()) {
+  if (constructor_function_ != NULL && kind_ == GetInitialFastElementsKind()) {
     // No need for a context lookup if the kind_ matches the initial
     // map, because we can just load the map in that case.
     HObjectAccess access = HObjectAccess::ForPrototypeOrInitialMap();
@@ -7355,18 +7355,30 @@ void HOptimizedGraphBuilder::VisitCall(Call* expr) {
   if (prop != NULL) {
     if (!prop->key()->IsPropertyName()) {
       // Keyed function call.
-      CHECK_ALIVE(VisitArgument(prop->obj()));
-
+      CHECK_ALIVE(VisitForValue(prop->obj()));
       CHECK_ALIVE(VisitForValue(prop->key()));
+
       // Push receiver and key like the non-optimized code generator expects it.
       HValue* key = Pop();
       HValue* receiver = Pop();
       Push(key);
-      Push(receiver);
-
+      Push(Add<HPushArgument>(receiver));
       CHECK_ALIVE(VisitArgumentList(expr->arguments()));
 
-      call = New<HCallKeyed>(key, argument_count);
+      if (expr->IsMonomorphic()) {
+        BuildCheckHeapObject(receiver);
+        ElementsKind kind = expr->KeyedArrayCallIsHoley()
+            ? FAST_HOLEY_ELEMENTS : FAST_ELEMENTS;
+
+        Handle<Map> map(isolate()->get_initial_js_array_map(kind));
+
+        HValue* function = BuildMonomorphicElementAccess(
+            receiver, key, NULL, NULL, map, false, STANDARD_STORE);
+
+        call = New<HCallFunction>(function, argument_count);
+      } else {
+        call = New<HCallKeyed>(key, argument_count);
+      }
       Drop(argument_count + 1);  // 1 is the key.
       return ast_context()->ReturnInstruction(call, expr->id());
     }