In-heap small typed arrays

src/typedarray.js

Index: src/typedarray.js
diff --git a/src/typedarray.js b/src/typedarray.js
index 0c0cb71b2a3bf883972384a8cb1d86be23baa299..d54db3433c1aa0911c3b3675adaf40c77364b5eb 100644
--- a/src/typedarray.js
+++ b/src/typedarray.js
@@ -92,8 +92,12 @@ macro TYPED_ARRAY_CONSTRUCTOR(ARRAY_ID, NAME, ELEMENT_SIZE)
       throw MakeRangeError("invalid_typed_array_length");
     }
     var byteLength = l * ELEMENT_SIZE;
-    var buffer = new $ArrayBuffer(byteLength);
-    %TypedArrayInitialize(obj, ARRAY_ID, buffer, 0, byteLength);
+    if (byteLength > %TypedArrayInHeapThreshold()) {
+      var buffer = new $ArrayBuffer(byteLength);
+      %TypedArrayInitialize(obj, ARRAY_ID, buffer, 0, byteLength);
+    } else {
+      %TypedArrayInitialize(obj, ARRAY_ID, null, 0, byteLength);
+    }
   }
 
   function NAMEConstructByArrayLike(obj, arrayLike) {
@@ -167,8 +171,8 @@ function CreateSubArray(elementSize, constructor) {
     }
     var newLength = endInt - beginInt;
     var beginByteOffset =
-        %TypedArrayGetByteOffset(this) + beginInt * elementSize;
-    return new constructor(%TypedArrayGetBuffer(this),
+        this.byteOffset + beginInt * elementSize;
+    return new constructor(this.buffer,
                            beginByteOffset, newLength);
   }
 }