First implementation of fast path for instantiation of array literals composed of doubles.

src/hydrogen.cc

 // Copyright 2012 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 3657 matching lines @@
 static bool IsFastLiteral(Handle<JSObject> boilerplate,
                           int max_depth,
                           int* max_properties,
                           int* total_size) {
   ASSERT(max_depth >= 0 && *max_properties >= 0);
   if (max_depth == 0) return false;
 
   Handle<FixedArrayBase> elements(boilerplate->elements());
   if (elements->length() > 0 &&
       elements->map() != boilerplate->GetHeap()->fixed_cow_array_map()) {
-    if (!boilerplate->HasFastElements()) return false;
-    int length = elements->length();
-    for (int i = 0; i < length; i++) {
-      if ((*max_properties)-- == 0) return false;
-      Handle<Object> value = JSObject::GetElement(boilerplate, i);
-      if (value->IsJSObject()) {
-        Handle<JSObject> value_object = Handle<JSObject>::cast(value);
-        if (!IsFastLiteral(value_object,
-                           max_depth - 1,
-                           max_properties,
-                           total_size)) {
-          return false;
+    if (boilerplate->HasFastDoubleElements()) {
+      *total_size += FixedDoubleArray::SizeFor(elements->length());
+    } else if (boilerplate->HasFastElements()) {
+      int length = elements->length();
+      for (int i = 0; i < length; i++) {
+        if ((*max_properties)-- == 0) return false;
+        Handle<Object> value = JSObject::GetElement(boilerplate, i);
+        if (value->IsJSObject()) {
+          Handle<JSObject> value_object = Handle<JSObject>::cast(value);
+          if (!IsFastLiteral(value_object,
+                             max_depth - 1,
+                             max_properties,
+                             total_size)) {
+            return false;
+          }
         }
       }
+      *total_size += FixedArray::SizeFor(length);
+    } else {
+      return false;
     }
-    *total_size += FixedArray::SizeFor(length);
   }
 
   Handle<FixedArray> properties(boilerplate->properties());
   if (properties->length() > 0) {
     return false;
   } else {
     int nof = boilerplate->map()->inobject_properties();
     for (int i = 0; i < nof; i++) {
       if ((*max_properties)-- == 0) return false;
       Handle<Object> value(boilerplate->InObjectPropertyAt(i));
@@ skipping 4452 matching lines @@
     }
   }
 
 #ifdef DEBUG
   if (graph_ != NULL) graph_->Verify(false);  // No full verify.
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 
 } }  // namespace v8::internal