Fix Runtime_ArrayConcat to handle FAST_DOUBLE_ELEMENTS

TEST=mjsunit/elements-kind.js; stanford-crypto-sha256-iterative in debug mode

Review URL: http://codereview.chromium.org/8334028

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9880 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/runtime.cc

@@ -9694,6 +9694,7 @@ 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:
     case FAST_ELEMENTS: {
       // Fast elements can't have lengths that are not representable by
       // a 32-bit signed integer.
@@ -9705,6 +9706,10 @@ static uint32_t EstimateElementCount(Handle<JSArray> array) {
       }
       break;
     }
+    case FAST_DOUBLE_ELEMENTS:
+      // TODO(1810): Decide if it's worthwhile to implement this.
+      UNREACHABLE();
+      break;
     case DICTIONARY_ELEMENTS: {
       Handle<NumberDictionary> dictionary(
           NumberDictionary::cast(array->elements()));
@@ -9717,7 +9722,16 @@ static uint32_t EstimateElementCount(Handle<JSArray> array) {
       }
       break;
     }
-    default:
+    case NON_STRICT_ARGUMENTS_ELEMENTS:
+    case EXTERNAL_BYTE_ELEMENTS:
+    case EXTERNAL_UNSIGNED_BYTE_ELEMENTS:
+    case EXTERNAL_SHORT_ELEMENTS:
+    case EXTERNAL_UNSIGNED_SHORT_ELEMENTS:
+    case EXTERNAL_INT_ELEMENTS:
+    case EXTERNAL_UNSIGNED_INT_ELEMENTS:
+    case EXTERNAL_FLOAT_ELEMENTS:
+    case EXTERNAL_DOUBLE_ELEMENTS:
+    case EXTERNAL_PIXEL_ELEMENTS:
       // External arrays are always dense.
       return length;
   }
@@ -9795,6 +9809,11 @@ static void CollectElementIndices(Handle<JSObject> object,
       }
       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();
@@ -9925,6 +9944,11 @@ static bool IterateElements(Isolate* isolate,
       }
       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);
@@ -10035,6 +10059,13 @@ RUNTIME_FUNCTION(MaybeObject*, Runtime_ArrayConcat) {
       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 =

test/mjsunit/elements-kind.js

@@ -305,5 +305,17 @@ if (support_smi_only_arrays) {
   assertTrue(%HaveSameMap(e, f));
 }
 
+// Test if Array.concat() works correctly with DOUBLE elements.
+if (support_smi_only_arrays) {
+  var a = [1, 2];
+  assertKind(elements_kind.fast_smi_only, a);
+  var b = [4.5, 5.5];
+  assertKind(elements_kind.fast_double, b);
+  var c = a.concat(b);
+  assertEquals([1, 2, 4.5, 5.5], c);
+  // TODO(1810): Change implementation so that we get DOUBLE elements here?
+  assertKind(elements_kind.fast, c);
+}
+
 // Throw away type information in the ICs for next stress run.
 gc();