Fix Runtime_ArrayConcat to handle FAST_DOUBLE_ELEMENTS

src/runtime.cc

 // Copyright 2011 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 9677 matching lines @@
   // JSObject::kMaxElementCount.
   uint32_t index_offset_;
   bool fast_elements_;
 };
 
 
 static uint32_t EstimateElementCount(Handle<JSArray> array) {
   uint32_t length = static_cast<uint32_t>(array->length()->Number());
   int element_count = 0;
   switch (array->GetElementsKind()) {
+    case FAST_SMI_ONLY_ELEMENTS:

[danno, 2011/11/04 10:02:04]

Add all of the other elements kinds explicitly to the case that either are
UNREACHABLE or return length, remove the default. 

     case FAST_ELEMENTS: {
       // Fast elements can't have lengths that are not representable by
       // a 32-bit signed integer.
       ASSERT(static_cast<int32_t>(FixedArray::kMaxLength) >= 0);
       int fast_length = static_cast<int>(length);
       Handle<FixedArray> elements(FixedArray::cast(array->elements()));
       for (int i = 0; i < fast_length; i++) {
         if (!elements->get(i)->IsTheHole()) element_count++;
       }
       break;
@@ skipping 81 matching lines @@
       Handle<FixedArray> elements(FixedArray::cast(object->elements()));
       uint32_t length = static_cast<uint32_t>(elements->length());
       if (range < length) length = range;
       for (uint32_t i = 0; i < length; i++) {
         if (!elements->get(i)->IsTheHole()) {
           indices->Add(i);
         }
       }
       break;
     }
+    case FAST_DOUBLE_ELEMENTS: {
+      // TODO(1810): Decide if it's worthwhile to implement this.
+      UNREACHABLE();
+      break;
+    }
     case DICTIONARY_ELEMENTS: {
       Handle<NumberDictionary> dict(NumberDictionary::cast(object->elements()));
       uint32_t capacity = dict->Capacity();
       for (uint32_t j = 0; j < capacity; j++) {
         HandleScope loop_scope;
         Handle<Object> k(dict->KeyAt(j));
         if (dict->IsKey(*k)) {
           ASSERT(k->IsNumber());
           uint32_t index = static_cast<uint32_t>(k->Number());
           if (index < range) {
@@ skipping 110 matching lines @@
         } else if (receiver->HasElement(j)) {
           // Call GetElement on receiver, not its prototype, or getters won't
           // have the correct receiver.
           element_value = Object::GetElement(receiver, j);
           RETURN_IF_EMPTY_HANDLE_VALUE(isolate, element_value, false);
           visitor->visit(j, element_value);
         }
       }
       break;
     }
+    case FAST_DOUBLE_ELEMENTS: {
+      // TODO(1810): Decide if it's worthwhile to implement this.
+      UNREACHABLE();
+      break;
+    }
     case DICTIONARY_ELEMENTS: {
       Handle<NumberDictionary> dict(receiver->element_dictionary());
       List<uint32_t> indices(dict->Capacity() / 2);
       // Collect all indices in the object and the prototypes less
       // than length. This might introduce duplicates in the indices list.
       CollectElementIndices(receiver, length, &indices);
       indices.Sort(&compareUInt32);
       int j = 0;
       int n = indices.length();
       while (j < n) {
@@ skipping 90 matching lines @@
   uint32_t estimate_result_length = 0;
   uint32_t estimate_nof_elements = 0;
   {
     for (int i = 0; i < argument_count; i++) {
       HandleScope loop_scope;
       Handle<Object> obj(elements->get(i));
       uint32_t length_estimate;
       uint32_t element_estimate;
       if (obj->IsJSArray()) {
         Handle<JSArray> array(Handle<JSArray>::cast(obj));
+        // TODO(1810): Find out if it's worthwhile to properly support
+        // arbitrary ElementsKinds. For now, pessimistically transition to
+        // FAST_ELEMENTS.
+        if (array->HasFastDoubleElements()) {
+          array = Handle<JSArray>::cast(
+              TransitionElementsKind(array, FAST_ELEMENTS));
+        }
         length_estimate =
             static_cast<uint32_t>(array->length()->Number());
         element_estimate =
             EstimateElementCount(array);
       } else {
         length_estimate = 1;
         element_estimate = 1;
       }
       // Avoid overflows by capping at kMaxElementCount.
       if (JSObject::kMaxElementCount - estimate_result_length <
@@ skipping 3469 matching lines @@
   } else {
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags);
   }
 }
 
 
 } }  // namespace v8::internal