First cut at impementing ES6 TypedArrays in V8.

src/typedarray.js

 // Copyright 2013 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 64 matching lines @@
   }
 
   var newLen = fin - first;
   // TODO(dslomov): implement inheritance
   var result = new $ArrayBuffer(newLen);
 
   %ArrayBufferSliceImpl(this, result, first);
   return result;
 }
 
+// --------------- Typed Arrays ---------------------
+
+function CreateTypedArrayConstructor(name, elementSize, arrayId, constr) {

[rossberg, 2013/04/16 13:30:43]

Nit: spell out constructor, it still fits the line. :)

[Dmitry Lomov (no reviews), 2013/04/16 13:47:13]

Done.

+  return function (buffer, byteOffset, length) {
+    if (%_IsConstructCall()) {
+      if (!IS_ARRAYBUFFER(buffer)) {
+        throw MakeTypeError("Type error!");
+      }
+      var offset = IS_UNDEFINED(byteOffset)
+        ? 0 : offset = TO_POSITIVE_INTEGER(byteOffset);
+
+      if (offset % elementSize !== 0) {
+        throw MakeRangeError("invalid_typed_array_alignment",
+            "start offset", name, elementSize);
+      }
+      var bufferByteLength = %ArrayBufferGetByteLength(buffer);
+      if (offset >= bufferByteLength) {
+        throw MakeRangeError("invalid_typed_array_offset");
+      }
+
+      var newByteLength;
+      var newLength;
+      if (IS_UNDEFINED(length)) {
+        if (bufferByteLength % elementSize !== 0) {
+          throw MakeRangeError("invalid_typed_array_alignment",
+            "byte length", name, elementSize);
+        }
+        newByteLength = bufferByteLength - offset;
+        newLength = newByteLength / elementSize;
+      } else {
+        var newLength = TO_POSITIVE_INTEGER(length);
+        newByteLength = newLength * elementSize;
+      }
+      if (newByteLength > bufferByteLength) {
+        throw MakeRangeError("invalid_typed_array_length");
+      }
+      %TypedArrayInitialize(this, arrayId, buffer, offset, newByteLength);
+    } else {
+      return new constr(buffer, byteOffset, length);
+    }
+  }
+}
+
+function TypedArrayGetBuffer() {
+  return %TypedArrayGetBuffer(this);
+}
+
+function TypedArrayGetByteLength() {
+  return %TypedArrayGetByteLength(this);
+}
+
+function TypedArrayGetByteOffset() {
+  return %TypedArrayGetByteOffset(this);
+}
+
+function TypedArrayGetLength() {
+  return %TypedArrayGetLength(this);
+}
+
 
 // -------------------------------------------------------------------
 
 function SetUpArrayBuffer() {
   %CheckIsBootstrapping();
 
-  // Set up the Uint16Array constructor function.
+  // Set up the ArrayBuffer constructor function.
   %SetCode($ArrayBuffer, ArrayBufferConstructor);
+  %FunctionSetPrototype($ArrayBuffer, new $Object());
 
   // Set up the constructor property on the ArrayBuffer prototype object.
   %SetProperty($ArrayBuffer.prototype, "constructor", $ArrayBuffer, DONT_ENUM);
 
   InstallGetter($ArrayBuffer.prototype, "byteLength", ArrayBufferGetByteLength);
 
   InstallFunctions($ArrayBuffer.prototype, DONT_ENUM, $Array(
       "slice", ArrayBufferSlice
   ));
 }
 
 SetUpArrayBuffer();
+
+function SetupTypedArray(arrayId, name, constructor, elementSize) {
+  var f = CreateTypedArrayConstructor(name, elementSize,
+                                      arrayId, constructor);
+  %SetCode(constructor, f);
+  %FunctionSetPrototype(constructor, new $Object());
+
+  %SetProperty(constructor.prototype,
+               "constructor", constructor, DONT_ENUM);
+  %SetProperty(constructor.prototype,
+               "BYTES_PER_ELEMENT", elementSize,
+               READ_ONLY | DONT_ENUM | DONT_DELETE);
+  InstallGetter(constructor.prototype, "buffer", TypedArrayGetBuffer);
+  InstallGetter(constructor.prototype, "byteOffset", TypedArrayGetByteOffset);
+  InstallGetter(constructor.prototype, "byteLength", TypedArrayGetByteLength);
+  InstallGetter(constructor.prototype, "length", TypedArrayGetLength);
+}
+
+function SetupAllTypedArrays() {

[rossberg, 2013/04/16 13:30:43]

Nit: I'd remove this wrapper.

[Dmitry Lomov (no reviews), 2013/04/16 13:47:13]

Done. No pereference either way.
On 2013/04/16 13:30:43, rossberg wrote:

+  // arrayIds below should be synchronized with Runtime_TypedArrayInitialize.
+  SetupTypedArray(1, "Uint8Array", global.__Uint8Array, 1);
+  SetupTypedArray(2, "Int8Array", global.__Int8Array, 1);
+  SetupTypedArray(3, "Uint16Array", global.__Uint16Array, 2);
+  SetupTypedArray(4, "Int16Array", global.__Int16Array, 2);
+  SetupTypedArray(5, "Uint32Array", global.__Uint32Array, 4);
+  SetupTypedArray(6, "Int32Array", global.__Int32Array, 4);
+  SetupTypedArray(7, "Float32Array", global.__Float32Array, 4);
+  SetupTypedArray(8, "Float64Array", global.__Float64Array, 8);
+}
+
+SetupAllTypedArrays();
+