Split more runtime functions into seperate files.

src/runtime/runtime-typedarray.cc

Index: src/runtime/runtime-typedarray.cc
diff --git a/src/runtime/runtime-typedarray.cc b/src/runtime/runtime-typedarray.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c138a4febd6f3c8ebdfd205e7555c94c40598430
--- /dev/null
+++ b/src/runtime/runtime-typedarray.cc
@@ -0,0 +1,760 @@
+// Copyright 2014 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.
+
+#include "src/v8.h"
+
+#include "src/arguments.h"
+#include "src/runtime/runtime.h"
+#include "src/runtime/runtime-utils.h"
+
+
+namespace v8 {
+namespace internal {
+
+void Runtime::FreeArrayBuffer(Isolate* isolate,
+                              JSArrayBuffer* phantom_array_buffer) {
+  if (phantom_array_buffer->should_be_freed()) {
+    DCHECK(phantom_array_buffer->is_external());
+    free(phantom_array_buffer->backing_store());
+  }
+  if (phantom_array_buffer->is_external()) return;
+
+  size_t allocated_length =
+      NumberToSize(isolate, phantom_array_buffer->byte_length());
+
+  reinterpret_cast<v8::Isolate*>(isolate)
+      ->AdjustAmountOfExternalAllocatedMemory(
+          -static_cast<int64_t>(allocated_length));
+  CHECK(V8::ArrayBufferAllocator() != NULL);
+  V8::ArrayBufferAllocator()->Free(phantom_array_buffer->backing_store(),
+                                   allocated_length);
+}
+
+
+void Runtime::SetupArrayBuffer(Isolate* isolate,
+                               Handle<JSArrayBuffer> array_buffer,
+                               bool is_external, void* data,
+                               size_t allocated_length) {
+  DCHECK(array_buffer->GetInternalFieldCount() ==
+         v8::ArrayBuffer::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBuffer::kInternalFieldCount; i++) {
+    array_buffer->SetInternalField(i, Smi::FromInt(0));
+  }
+  array_buffer->set_backing_store(data);
+  array_buffer->set_flag(Smi::FromInt(0));
+  array_buffer->set_is_external(is_external);
+
+  Handle<Object> byte_length =
+      isolate->factory()->NewNumberFromSize(allocated_length);
+  CHECK(byte_length->IsSmi() || byte_length->IsHeapNumber());
+  array_buffer->set_byte_length(*byte_length);
+
+  array_buffer->set_weak_next(isolate->heap()->array_buffers_list());
+  isolate->heap()->set_array_buffers_list(*array_buffer);
+  array_buffer->set_weak_first_view(isolate->heap()->undefined_value());
+}
+
+
+bool Runtime::SetupArrayBufferAllocatingData(Isolate* isolate,
+                                             Handle<JSArrayBuffer> array_buffer,
+                                             size_t allocated_length,
+                                             bool initialize) {
+  void* data;
+  CHECK(V8::ArrayBufferAllocator() != NULL);
+  if (allocated_length != 0) {
+    if (initialize) {
+      data = V8::ArrayBufferAllocator()->Allocate(allocated_length);
+    } else {
+      data =
+          V8::ArrayBufferAllocator()->AllocateUninitialized(allocated_length);
+    }
+    if (data == NULL) return false;
+  } else {
+    data = NULL;
+  }
+
+  SetupArrayBuffer(isolate, array_buffer, false, data, allocated_length);
+
+  reinterpret_cast<v8::Isolate*>(isolate)
+      ->AdjustAmountOfExternalAllocatedMemory(allocated_length);
+
+  return true;
+}
+
+
+void Runtime::NeuterArrayBuffer(Handle<JSArrayBuffer> array_buffer) {
+  Isolate* isolate = array_buffer->GetIsolate();
+  for (Handle<Object> view_obj(array_buffer->weak_first_view(), isolate);
+       !view_obj->IsUndefined();) {
+    Handle<JSArrayBufferView> view(JSArrayBufferView::cast(*view_obj));
+    if (view->IsJSTypedArray()) {
+      JSTypedArray::cast(*view)->Neuter();
+    } else if (view->IsJSDataView()) {
+      JSDataView::cast(*view)->Neuter();
+    } else {
+      UNREACHABLE();
+    }
+    view_obj = handle(view->weak_next(), isolate);
+  }
+  array_buffer->Neuter();
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayBufferInitialize) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 2);
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, holder, 0);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(byteLength, 1);
+  if (!holder->byte_length()->IsUndefined()) {
+    // ArrayBuffer is already initialized; probably a fuzz test.
+    return *holder;
+  }
+  size_t allocated_length = 0;
+  if (!TryNumberToSize(isolate, *byteLength, &allocated_length)) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("invalid_array_buffer_length",
+                               HandleVector<Object>(NULL, 0)));
+  }
+  if (!Runtime::SetupArrayBufferAllocatingData(isolate, holder,
+                                               allocated_length)) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("invalid_array_buffer_length",
+                               HandleVector<Object>(NULL, 0)));
+  }
+  return *holder;
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayBufferGetByteLength) {
+  SealHandleScope shs(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(JSArrayBuffer, holder, 0);
+  return holder->byte_length();
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayBufferSliceImpl) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 3);
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, source, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, target, 1);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(first, 2);
+  RUNTIME_ASSERT(!source.is_identical_to(target));
+  size_t start = 0;
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *first, &start));
+  size_t target_length = NumberToSize(isolate, target->byte_length());
+
+  if (target_length == 0) return isolate->heap()->undefined_value();
+
+  size_t source_byte_length = NumberToSize(isolate, source->byte_length());
+  RUNTIME_ASSERT(start <= source_byte_length);
+  RUNTIME_ASSERT(source_byte_length - start >= target_length);
+  uint8_t* source_data = reinterpret_cast<uint8_t*>(source->backing_store());
+  uint8_t* target_data = reinterpret_cast<uint8_t*>(target->backing_store());
+  CopyBytes(target_data, source_data + start, target_length);
+  return isolate->heap()->undefined_value();
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayBufferIsView) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_CHECKED(Object, object, 0);
+  return isolate->heap()->ToBoolean(object->IsJSArrayBufferView());
+}
+
+
+RUNTIME_FUNCTION(Runtime_ArrayBufferNeuter) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, array_buffer, 0);
+  if (array_buffer->backing_store() == NULL) {
+    CHECK(Smi::FromInt(0) == array_buffer->byte_length());
+    return isolate->heap()->undefined_value();
+  }
+  DCHECK(!array_buffer->is_external());
+  void* backing_store = array_buffer->backing_store();
+  size_t byte_length = NumberToSize(isolate, array_buffer->byte_length());
+  array_buffer->set_is_external(true);
+  Runtime::NeuterArrayBuffer(array_buffer);
+  V8::ArrayBufferAllocator()->Free(backing_store, byte_length);
+  return isolate->heap()->undefined_value();
+}
+
+
+void Runtime::ArrayIdToTypeAndSize(int arrayId, ExternalArrayType* array_type,
+                                   ElementsKind* external_elements_kind,
+                                   ElementsKind* fixed_elements_kind,
+                                   size_t* element_size) {
+  switch (arrayId) {
+#define ARRAY_ID_CASE(Type, type, TYPE, ctype, size)      \
+  case ARRAY_ID_##TYPE:                                   \
+    *array_type = kExternal##Type##Array;                 \
+    *external_elements_kind = EXTERNAL_##TYPE##_ELEMENTS; \
+    *fixed_elements_kind = TYPE##_ELEMENTS;               \
+    *element_size = size;                                 \
+    break;
+
+    TYPED_ARRAYS(ARRAY_ID_CASE)
+#undef ARRAY_ID_CASE
+
+    default:
+      UNREACHABLE();
+  }
+}
+
+
+RUNTIME_FUNCTION(Runtime_TypedArrayInitialize) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 5);
+  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
+  CONVERT_SMI_ARG_CHECKED(arrayId, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, maybe_buffer, 2);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_offset_object, 3);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_length_object, 4);
+
+  RUNTIME_ASSERT(arrayId >= Runtime::ARRAY_ID_FIRST &&
+                 arrayId <= Runtime::ARRAY_ID_LAST);
+
+  ExternalArrayType array_type = kExternalInt8Array;  // Bogus initialization.
+  size_t element_size = 1;                            // Bogus initialization.
+  ElementsKind external_elements_kind =
+      EXTERNAL_INT8_ELEMENTS;                        // Bogus initialization.
+  ElementsKind fixed_elements_kind = INT8_ELEMENTS;  // Bogus initialization.
+  Runtime::ArrayIdToTypeAndSize(arrayId, &array_type, &external_elements_kind,
+                                &fixed_elements_kind, &element_size);
+  RUNTIME_ASSERT(holder->map()->elements_kind() == fixed_elements_kind);
+
+  size_t byte_offset = 0;
+  size_t byte_length = 0;
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *byte_offset_object, &byte_offset));
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *byte_length_object, &byte_length));
+
+  if (maybe_buffer->IsJSArrayBuffer()) {
+    Handle<JSArrayBuffer> buffer = Handle<JSArrayBuffer>::cast(maybe_buffer);
+    size_t array_buffer_byte_length =
+        NumberToSize(isolate, buffer->byte_length());
+    RUNTIME_ASSERT(byte_offset <= array_buffer_byte_length);
+    RUNTIME_ASSERT(array_buffer_byte_length - byte_offset >= byte_length);
+  } else {
+    RUNTIME_ASSERT(maybe_buffer->IsNull());
+  }
+
+  RUNTIME_ASSERT(byte_length % element_size == 0);
+  size_t length = byte_length / element_size;
+
+  if (length > static_cast<unsigned>(Smi::kMaxValue)) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("invalid_typed_array_length",
+                               HandleVector<Object>(NULL, 0)));
+  }
+
+  // All checks are done, now we can modify objects.
+
+  DCHECK(holder->GetInternalFieldCount() ==
+         v8::ArrayBufferView::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
+    holder->SetInternalField(i, Smi::FromInt(0));
+  }
+  Handle<Object> length_obj = isolate->factory()->NewNumberFromSize(length);
+  holder->set_length(*length_obj);
+  holder->set_byte_offset(*byte_offset_object);
+  holder->set_byte_length(*byte_length_object);
+
+  if (!maybe_buffer->IsNull()) {
+    Handle<JSArrayBuffer> buffer = Handle<JSArrayBuffer>::cast(maybe_buffer);
+    holder->set_buffer(*buffer);
+    holder->set_weak_next(buffer->weak_first_view());
+    buffer->set_weak_first_view(*holder);
+
+    Handle<ExternalArray> elements = isolate->factory()->NewExternalArray(
+        static_cast<int>(length), array_type,
+        static_cast<uint8_t*>(buffer->backing_store()) + byte_offset);
+    Handle<Map> map =
+        JSObject::GetElementsTransitionMap(holder, external_elements_kind);
+    JSObject::SetMapAndElements(holder, map, elements);
+    DCHECK(IsExternalArrayElementsKind(holder->map()->elements_kind()));
+  } else {
+    holder->set_buffer(Smi::FromInt(0));
+    holder->set_weak_next(isolate->heap()->undefined_value());
+    Handle<FixedTypedArrayBase> elements =
+        isolate->factory()->NewFixedTypedArray(static_cast<int>(length),
+                                               array_type);
+    holder->set_elements(*elements);
+  }
+  return isolate->heap()->undefined_value();
+}
+
+
+// Initializes a typed array from an array-like object.
+// If an array-like object happens to be a typed array of the same type,
+// initializes backing store using memove.
+//
+// Returns true if backing store was initialized or false otherwise.
+RUNTIME_FUNCTION(Runtime_TypedArrayInitializeFromArrayLike) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 4);
+  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
+  CONVERT_SMI_ARG_CHECKED(arrayId, 1);
+  CONVERT_ARG_HANDLE_CHECKED(Object, source, 2);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(length_obj, 3);
+
+  RUNTIME_ASSERT(arrayId >= Runtime::ARRAY_ID_FIRST &&
+                 arrayId <= Runtime::ARRAY_ID_LAST);
+
+  ExternalArrayType array_type = kExternalInt8Array;  // Bogus initialization.
+  size_t element_size = 1;                            // Bogus initialization.
+  ElementsKind external_elements_kind =
+      EXTERNAL_INT8_ELEMENTS;                        // Bogus intialization.
+  ElementsKind fixed_elements_kind = INT8_ELEMENTS;  // Bogus initialization.
+  Runtime::ArrayIdToTypeAndSize(arrayId, &array_type, &external_elements_kind,
+                                &fixed_elements_kind, &element_size);
+
+  RUNTIME_ASSERT(holder->map()->elements_kind() == fixed_elements_kind);
+
+  Handle<JSArrayBuffer> buffer = isolate->factory()->NewJSArrayBuffer();
+  if (source->IsJSTypedArray() &&
+      JSTypedArray::cast(*source)->type() == array_type) {
+    length_obj = Handle<Object>(JSTypedArray::cast(*source)->length(), isolate);
+  }
+  size_t length = 0;
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *length_obj, &length));
+
+  if ((length > static_cast<unsigned>(Smi::kMaxValue)) ||
+      (length > (kMaxInt / element_size))) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("invalid_typed_array_length",
+                               HandleVector<Object>(NULL, 0)));
+  }
+  size_t byte_length = length * element_size;
+
+  DCHECK(holder->GetInternalFieldCount() ==
+         v8::ArrayBufferView::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
+    holder->SetInternalField(i, Smi::FromInt(0));
+  }
+
+  // NOTE: not initializing backing store.
+  // We assume that the caller of this function will initialize holder
+  // with the loop
+  //      for(i = 0; i < length; i++) { holder[i] = source[i]; }
+  // We assume that the caller of this function is always a typed array
+  // constructor.
+  // If source is a typed array, this loop will always run to completion,
+  // so we are sure that the backing store will be initialized.
+  // Otherwise, the indexing operation might throw, so the loop will not
+  // run to completion and the typed array might remain partly initialized.
+  // However we further assume that the caller of this function is a typed array
+  // constructor, and the exception will propagate out of the constructor,
+  // therefore uninitialized memory will not be accessible by a user program.
+  //
+  // TODO(dslomov): revise this once we support subclassing.
+
+  if (!Runtime::SetupArrayBufferAllocatingData(isolate, buffer, byte_length,
+                                               false)) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("invalid_array_buffer_length",
+                               HandleVector<Object>(NULL, 0)));
+  }
+
+  holder->set_buffer(*buffer);
+  holder->set_byte_offset(Smi::FromInt(0));
+  Handle<Object> byte_length_obj(
+      isolate->factory()->NewNumberFromSize(byte_length));
+  holder->set_byte_length(*byte_length_obj);
+  holder->set_length(*length_obj);
+  holder->set_weak_next(buffer->weak_first_view());
+  buffer->set_weak_first_view(*holder);
+
+  Handle<ExternalArray> elements = isolate->factory()->NewExternalArray(
+      static_cast<int>(length), array_type,
+      static_cast<uint8_t*>(buffer->backing_store()));
+  Handle<Map> map =
+      JSObject::GetElementsTransitionMap(holder, external_elements_kind);
+  JSObject::SetMapAndElements(holder, map, elements);
+
+  if (source->IsJSTypedArray()) {
+    Handle<JSTypedArray> typed_array(JSTypedArray::cast(*source));
+
+    if (typed_array->type() == holder->type()) {
+      uint8_t* backing_store =
+          static_cast<uint8_t*>(typed_array->GetBuffer()->backing_store());
+      size_t source_byte_offset =
+          NumberToSize(isolate, typed_array->byte_offset());
+      memcpy(buffer->backing_store(), backing_store + source_byte_offset,
+             byte_length);
+      return isolate->heap()->true_value();
+    }
+  }
+
+  return isolate->heap()->false_value();
+}
+
+
+#define BUFFER_VIEW_GETTER(Type, getter, accessor)   \
+  RUNTIME_FUNCTION(Runtime_##Type##Get##getter) {    \
+    HandleScope scope(isolate);                      \
+    DCHECK(args.length() == 1);                      \
+    CONVERT_ARG_HANDLE_CHECKED(JS##Type, holder, 0); \
+    return holder->accessor();                       \
+  }
+
+BUFFER_VIEW_GETTER(ArrayBufferView, ByteLength, byte_length)
+BUFFER_VIEW_GETTER(ArrayBufferView, ByteOffset, byte_offset)
+BUFFER_VIEW_GETTER(TypedArray, Length, length)
+BUFFER_VIEW_GETTER(DataView, Buffer, buffer)
+
+#undef BUFFER_VIEW_GETTER
+
+RUNTIME_FUNCTION(Runtime_TypedArrayGetBuffer) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 1);
+  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, holder, 0);
+  return *holder->GetBuffer();
+}
+
+
+// Return codes for Runtime_TypedArraySetFastCases.
+// Should be synchronized with typedarray.js natives.
+enum TypedArraySetResultCodes {
+  // Set from typed array of the same type.
+  // This is processed by TypedArraySetFastCases
+  TYPED_ARRAY_SET_TYPED_ARRAY_SAME_TYPE = 0,
+  // Set from typed array of the different type, overlapping in memory.
+  TYPED_ARRAY_SET_TYPED_ARRAY_OVERLAPPING = 1,
+  // Set from typed array of the different type, non-overlapping.
+  TYPED_ARRAY_SET_TYPED_ARRAY_NONOVERLAPPING = 2,
+  // Set from non-typed array.
+  TYPED_ARRAY_SET_NON_TYPED_ARRAY = 3
+};
+
+
+RUNTIME_FUNCTION(Runtime_TypedArraySetFastCases) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 3);
+  if (!args[0]->IsJSTypedArray()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewTypeError("not_typed_array", HandleVector<Object>(NULL, 0)));
+  }
+
+  if (!args[1]->IsJSTypedArray())
+    return Smi::FromInt(TYPED_ARRAY_SET_NON_TYPED_ARRAY);
+
+  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, target_obj, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSTypedArray, source_obj, 1);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset_obj, 2);
+
+  Handle<JSTypedArray> target(JSTypedArray::cast(*target_obj));
+  Handle<JSTypedArray> source(JSTypedArray::cast(*source_obj));
+  size_t offset = 0;
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *offset_obj, &offset));
+  size_t target_length = NumberToSize(isolate, target->length());
+  size_t source_length = NumberToSize(isolate, source->length());
+  size_t target_byte_length = NumberToSize(isolate, target->byte_length());
+  size_t source_byte_length = NumberToSize(isolate, source->byte_length());
+  if (offset > target_length || offset + source_length > target_length ||
+      offset + source_length < offset) {  // overflow
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewRangeError("typed_array_set_source_too_large",
+                               HandleVector<Object>(NULL, 0)));
+  }
+
+  size_t target_offset = NumberToSize(isolate, target->byte_offset());
+  size_t source_offset = NumberToSize(isolate, source->byte_offset());
+  uint8_t* target_base =
+      static_cast<uint8_t*>(target->GetBuffer()->backing_store()) +
+      target_offset;
+  uint8_t* source_base =
+      static_cast<uint8_t*>(source->GetBuffer()->backing_store()) +
+      source_offset;
+
+  // Typed arrays of the same type: use memmove.
+  if (target->type() == source->type()) {
+    memmove(target_base + offset * target->element_size(), source_base,
+            source_byte_length);
+    return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_SAME_TYPE);
+  }
+
+  // Typed arrays of different types over the same backing store
+  if ((source_base <= target_base &&
+       source_base + source_byte_length > target_base) ||
+      (target_base <= source_base &&
+       target_base + target_byte_length > source_base)) {
+    // We do not support overlapping ArrayBuffers
+    DCHECK(target->GetBuffer()->backing_store() ==
+           source->GetBuffer()->backing_store());
+    return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_OVERLAPPING);
+  } else {  // Non-overlapping typed arrays
+    return Smi::FromInt(TYPED_ARRAY_SET_TYPED_ARRAY_NONOVERLAPPING);
+  }
+}
+
+
+RUNTIME_FUNCTION(Runtime_TypedArrayMaxSizeInHeap) {
+  DCHECK(args.length() == 0);
+  DCHECK_OBJECT_SIZE(FLAG_typed_array_max_size_in_heap +
+                     FixedTypedArrayBase::kDataOffset);
+  return Smi::FromInt(FLAG_typed_array_max_size_in_heap);
+}
+
+
+RUNTIME_FUNCTION(Runtime_DataViewInitialize) {
+  HandleScope scope(isolate);
+  DCHECK(args.length() == 4);
+  CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);
+  CONVERT_ARG_HANDLE_CHECKED(JSArrayBuffer, buffer, 1);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_offset, 2);
+  CONVERT_NUMBER_ARG_HANDLE_CHECKED(byte_length, 3);
+
+  DCHECK(holder->GetInternalFieldCount() ==
+         v8::ArrayBufferView::kInternalFieldCount);
+  for (int i = 0; i < v8::ArrayBufferView::kInternalFieldCount; i++) {
+    holder->SetInternalField(i, Smi::FromInt(0));
+  }
+  size_t buffer_length = 0;
+  size_t offset = 0;
+  size_t length = 0;
+  RUNTIME_ASSERT(
+      TryNumberToSize(isolate, buffer->byte_length(), &buffer_length));
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *byte_offset, &offset));
+  RUNTIME_ASSERT(TryNumberToSize(isolate, *byte_length, &length));
+
+  // TODO(jkummerow): When we have a "safe numerics" helper class, use it here.
+  // Entire range [offset, offset + length] must be in bounds.
+  RUNTIME_ASSERT(offset <= buffer_length);
+  RUNTIME_ASSERT(offset + length <= buffer_length);
+  // No overflow.
+  RUNTIME_ASSERT(offset + length >= offset);
+
+  holder->set_buffer(*buffer);
+  holder->set_byte_offset(*byte_offset);
+  holder->set_byte_length(*byte_length);
+
+  holder->set_weak_next(buffer->weak_first_view());
+  buffer->set_weak_first_view(*holder);
+
+  return isolate->heap()->undefined_value();
+}
+
+
+inline static bool NeedToFlipBytes(bool is_little_endian) {
+#ifdef V8_TARGET_LITTLE_ENDIAN
+  return !is_little_endian;
+#else
+  return is_little_endian;
+#endif
+}
+
+
+template <int n>
+inline void CopyBytes(uint8_t* target, uint8_t* source) {
+  for (int i = 0; i < n; i++) {
+    *(target++) = *(source++);
+  }
+}
+
+
+template <int n>
+inline void FlipBytes(uint8_t* target, uint8_t* source) {
+  source = source + (n - 1);
+  for (int i = 0; i < n; i++) {
+    *(target++) = *(source--);
+  }
+}
+
+
+template <typename T>
+inline static bool DataViewGetValue(Isolate* isolate,
+                                    Handle<JSDataView> data_view,
+                                    Handle<Object> byte_offset_obj,
+                                    bool is_little_endian, T* result) {
+  size_t byte_offset = 0;
+  if (!TryNumberToSize(isolate, *byte_offset_obj, &byte_offset)) {
+    return false;
+  }
+  Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(data_view->buffer()));
+
+  size_t data_view_byte_offset =
+      NumberToSize(isolate, data_view->byte_offset());
+  size_t data_view_byte_length =
+      NumberToSize(isolate, data_view->byte_length());
+  if (byte_offset + sizeof(T) > data_view_byte_length ||
+      byte_offset + sizeof(T) < byte_offset) {  // overflow
+    return false;
+  }
+
+  union Value {
+    T data;
+    uint8_t bytes[sizeof(T)];
+  };
+
+  Value value;
+  size_t buffer_offset = data_view_byte_offset + byte_offset;
+  DCHECK(NumberToSize(isolate, buffer->byte_length()) >=
+         buffer_offset + sizeof(T));
+  uint8_t* source =
+      static_cast<uint8_t*>(buffer->backing_store()) + buffer_offset;
+  if (NeedToFlipBytes(is_little_endian)) {
+    FlipBytes<sizeof(T)>(value.bytes, source);
+  } else {
+    CopyBytes<sizeof(T)>(value.bytes, source);
+  }
+  *result = value.data;
+  return true;
+}
+
+
+template <typename T>
+static bool DataViewSetValue(Isolate* isolate, Handle<JSDataView> data_view,
+                             Handle<Object> byte_offset_obj,
+                             bool is_little_endian, T data) {
+  size_t byte_offset = 0;
+  if (!TryNumberToSize(isolate, *byte_offset_obj, &byte_offset)) {
+    return false;
+  }
+  Handle<JSArrayBuffer> buffer(JSArrayBuffer::cast(data_view->buffer()));
+
+  size_t data_view_byte_offset =
+      NumberToSize(isolate, data_view->byte_offset());
+  size_t data_view_byte_length =
+      NumberToSize(isolate, data_view->byte_length());
+  if (byte_offset + sizeof(T) > data_view_byte_length ||
+      byte_offset + sizeof(T) < byte_offset) {  // overflow
+    return false;
+  }
+
+  union Value {
+    T data;
+    uint8_t bytes[sizeof(T)];
+  };
+
+  Value value;
+  value.data = data;
+  size_t buffer_offset = data_view_byte_offset + byte_offset;
+  DCHECK(NumberToSize(isolate, buffer->byte_length()) >=
+         buffer_offset + sizeof(T));
+  uint8_t* target =
+      static_cast<uint8_t*>(buffer->backing_store()) + buffer_offset;
+  if (NeedToFlipBytes(is_little_endian)) {
+    FlipBytes<sizeof(T)>(target, value.bytes);
+  } else {
+    CopyBytes<sizeof(T)>(target, value.bytes);
+  }
+  return true;
+}
+
+
+#define DATA_VIEW_GETTER(TypeName, Type, Converter)                   \
+  RUNTIME_FUNCTION(Runtime_DataViewGet##TypeName) {                   \
+    HandleScope scope(isolate);                                       \
+    DCHECK(args.length() == 3);                                       \
+    CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);                \
+    CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset, 1);                     \
+    CONVERT_BOOLEAN_ARG_CHECKED(is_little_endian, 2);                 \
+    Type result;                                                      \
+    if (DataViewGetValue(isolate, holder, offset, is_little_endian,   \
+                         &result)) {                                  \
+      return *isolate->factory()->Converter(result);                  \
+    } else {                                                          \
+      THROW_NEW_ERROR_RETURN_FAILURE(                                 \
+          isolate, NewRangeError("invalid_data_view_accessor_offset", \
+                                 HandleVector<Object>(NULL, 0)));     \
+    }                                                                 \
+  }
+
+DATA_VIEW_GETTER(Uint8, uint8_t, NewNumberFromUint)
+DATA_VIEW_GETTER(Int8, int8_t, NewNumberFromInt)
+DATA_VIEW_GETTER(Uint16, uint16_t, NewNumberFromUint)
+DATA_VIEW_GETTER(Int16, int16_t, NewNumberFromInt)
+DATA_VIEW_GETTER(Uint32, uint32_t, NewNumberFromUint)
+DATA_VIEW_GETTER(Int32, int32_t, NewNumberFromInt)
+DATA_VIEW_GETTER(Float32, float, NewNumber)
+DATA_VIEW_GETTER(Float64, double, NewNumber)
+
+#undef DATA_VIEW_GETTER
+
+
+template <typename T>
+static T DataViewConvertValue(double value);
+
+
+template <>
+int8_t DataViewConvertValue<int8_t>(double value) {
+  return static_cast<int8_t>(DoubleToInt32(value));
+}
+
+
+template <>
+int16_t DataViewConvertValue<int16_t>(double value) {
+  return static_cast<int16_t>(DoubleToInt32(value));
+}
+
+
+template <>
+int32_t DataViewConvertValue<int32_t>(double value) {
+  return DoubleToInt32(value);
+}
+
+
+template <>
+uint8_t DataViewConvertValue<uint8_t>(double value) {
+  return static_cast<uint8_t>(DoubleToUint32(value));
+}
+
+
+template <>
+uint16_t DataViewConvertValue<uint16_t>(double value) {
+  return static_cast<uint16_t>(DoubleToUint32(value));
+}
+
+
+template <>
+uint32_t DataViewConvertValue<uint32_t>(double value) {
+  return DoubleToUint32(value);
+}
+
+
+template <>
+float DataViewConvertValue<float>(double value) {
+  return static_cast<float>(value);
+}
+
+
+template <>
+double DataViewConvertValue<double>(double value) {
+  return value;
+}
+
+
+#define DATA_VIEW_SETTER(TypeName, Type)                                  \
+  RUNTIME_FUNCTION(Runtime_DataViewSet##TypeName) {                       \
+    HandleScope scope(isolate);                                           \
+    DCHECK(args.length() == 4);                                           \
+    CONVERT_ARG_HANDLE_CHECKED(JSDataView, holder, 0);                    \
+    CONVERT_NUMBER_ARG_HANDLE_CHECKED(offset, 1);                         \
+    CONVERT_NUMBER_ARG_HANDLE_CHECKED(value, 2);                          \
+    CONVERT_BOOLEAN_ARG_CHECKED(is_little_endian, 3);                     \
+    Type v = DataViewConvertValue<Type>(value->Number());                 \
+    if (DataViewSetValue(isolate, holder, offset, is_little_endian, v)) { \
+      return isolate->heap()->undefined_value();                          \
+    } else {                                                              \
+      THROW_NEW_ERROR_RETURN_FAILURE(                                     \
+          isolate, NewRangeError("invalid_data_view_accessor_offset",     \
+                                 HandleVector<Object>(NULL, 0)));         \
+    }                                                                     \
+  }
+
+DATA_VIEW_SETTER(Uint8, uint8_t)
+DATA_VIEW_SETTER(Int8, int8_t)
+DATA_VIEW_SETTER(Uint16, uint16_t)
+DATA_VIEW_SETTER(Int16, int16_t)
+DATA_VIEW_SETTER(Uint32, uint32_t)
+DATA_VIEW_SETTER(Int32, int32_t)
+DATA_VIEW_SETTER(Float32, float)
+DATA_VIEW_SETTER(Float64, double)
+
+#undef DATA_VIEW_SETTER
+}
+}  // namespace v8::internal