Also allocate small typed arrays on heap when initialized from an array-like

src/typedarray.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, utils) {
 
 "use strict";
 
 %CheckIsBootstrapping();
 
@@ skipping 70 matching lines @@
     newByteLength = bufferByteLength - offset;
     newLength = newByteLength / ELEMENT_SIZE;
   } else {
     var newLength = length;
     newByteLength = newLength * ELEMENT_SIZE;
   }
   if ((offset + newByteLength > bufferByteLength)
       || (newLength > %_MaxSmi())) {
     throw MakeRangeError(kInvalidTypedArrayLength);
   }
-  %_TypedArrayInitialize(obj, ARRAY_ID, buffer, offset, newByteLength);
+  %_TypedArrayInitialize(obj, ARRAY_ID, buffer, offset, newByteLength, true);
 }
 
 function NAMEConstructByLength(obj, length) {
   var l = IS_UNDEFINED(length) ?
     0 : $toPositiveInteger(length, kInvalidTypedArrayLength);
   if (l > %_MaxSmi()) {
     throw MakeRangeError(kInvalidTypedArrayLength);
   }
   var byteLength = l * ELEMENT_SIZE;
   if (byteLength > %_TypedArrayMaxSizeInHeap()) {
     var buffer = new GlobalArrayBuffer(byteLength);
-    %_TypedArrayInitialize(obj, ARRAY_ID, buffer, 0, byteLength);
+    %_TypedArrayInitialize(obj, ARRAY_ID, buffer, 0, byteLength, true);
   } else {
-    %_TypedArrayInitialize(obj, ARRAY_ID, null, 0, byteLength);
+    %_TypedArrayInitialize(obj, ARRAY_ID, null, 0, byteLength, true);
   }
 }
 
 function NAMEConstructByArrayLike(obj, arrayLike) {
   var length = arrayLike.length;
   var l = $toPositiveInteger(length, kInvalidTypedArrayLength);
 
   if (l > %_MaxSmi()) {
     throw MakeRangeError(kInvalidTypedArrayLength);
   }
-  if(!%TypedArrayInitializeFromArrayLike(obj, ARRAY_ID, arrayLike, l)) {
+  var initialized = false;
+  var byteLength = l * ELEMENT_SIZE;
+  if (byteLength <= %_TypedArrayMaxSizeInHeap()) {
+    %_TypedArrayInitialize(obj, ARRAY_ID, null, 0, byteLength, false);
+  } else {
+    initialized =
+        %TypedArrayInitializeFromArrayLike(obj, ARRAY_ID, arrayLike, l);
+  }
+  if (!initialized) {
     for (var i = 0; i < l; i++) {
       // It is crucial that we let any execptions from arrayLike[i]
       // propagate outside the function.
       obj[i] = arrayLike[i];
     }
   }
 }
 
 function NAMEConstructor(arg1, arg2, arg3) {
   if (%_IsConstructCall()) {
@@ skipping 338 matching lines @@
   "setUint32", DataViewSetUint32JS,
 
   "getFloat32", DataViewGetFloat32JS,
   "setFloat32", DataViewSetFloat32JS,
 
   "getFloat64", DataViewGetFloat64JS,
   "setFloat64", DataViewSetFloat64JS
 ]);
 
 })