[turbofan] Fix typed lowering of typed array loads/stores.

R=jarin@chromium.org

Review URL: https://codereview.chromium.org/646483003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24514 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/compiler/js-typed-lowering.cc

@@ -541,23 +541,26 @@ Reduction JSTypedLowering::ReduceJSLoadProperty(Node* node) {
         Handle<JSTypedArray>::cast(base_type->AsConstant()->Value());
     if (IsExternalArrayElementsKind(array->map()->elements_kind())) {
       ExternalArrayType type = array->type();
-      uint32_t length;
-      CHECK(array->length()->ToUint32(&length));
+      uint32_t byte_length;
+      if (array->byte_length()->ToUint32(&byte_length)) {
         Node* elements = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForJSObjectElements()), base,
             graph()->start());
         Node* pointer = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForExternalArrayPointer()),
             elements, elements);
+        Node* length = jsgraph()->Uint32Constant(
+            static_cast<uint32_t>(byte_length / array->element_size()));
         Node* effect = NodeProperties::GetEffectInput(node);
         Node* control = NodeProperties::GetControlInput(node);
         Node* load = graph()->NewNode(
             simplified()->LoadElement(
                 AccessBuilder::ForTypedArrayElement(type, true)),
-          pointer, key, jsgraph()->Uint32Constant(length), effect, control);
+            pointer, key, length, effect, control);
         return ReplaceEagerly(node, load);
       }
     }
+  }
   return NoChange();
 }
 
@@ -577,24 +580,26 @@ Reduction JSTypedLowering::ReduceJSStoreProperty(Node* node) {
         Handle<JSTypedArray>::cast(base_type->AsConstant()->Value());
     if (IsExternalArrayElementsKind(array->map()->elements_kind())) {
       ExternalArrayType type = array->type();
-      uint32_t length;
-      CHECK(array->length()->ToUint32(&length));
+      uint32_t byte_length;
+      if (array->byte_length()->ToUint32(&byte_length)) {
         Node* elements = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForJSObjectElements()), base,
             graph()->start());
         Node* pointer = graph()->NewNode(
             simplified()->LoadField(AccessBuilder::ForExternalArrayPointer()),
             elements, elements);
+        Node* length = jsgraph()->Uint32Constant(
+            static_cast<uint32_t>(byte_length / array->element_size()));
         Node* effect = NodeProperties::GetEffectInput(node);
         Node* control = NodeProperties::GetControlInput(node);
-      Node* store =
-          graph()->NewNode(simplified()->StoreElement(
+        Node* store = graph()->NewNode(
+            simplified()->StoreElement(
                 AccessBuilder::ForTypedArrayElement(type, true)),
-                           pointer, key, jsgraph()->Uint32Constant(length),
-                           value, effect, control);
+            pointer, key, length, value, effect, control);
         return ReplaceEagerly(node, store);
       }
     }
+  }
   return NoChange();
 }
 

src/factory.cc

@@ -1731,6 +1731,19 @@ ElementsKind GetExternalArrayElementsKind(ExternalArrayType type) {
 }
 
 
+size_t GetExternalArrayElementSize(ExternalArrayType type) {
+  switch (type) {
+#define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
+  case kExternal##Type##Array:                          \
+    return size;
+    TYPED_ARRAYS(TYPED_ARRAY_CASE)
+  }
+  UNREACHABLE();
+  return 0;
+#undef TYPED_ARRAY_CASE
+}
+
+
 JSFunction* GetTypedArrayFun(ExternalArrayType type, Isolate* isolate) {
   Context* native_context = isolate->context()->native_context();
   switch (type) {
@@ -1769,7 +1782,9 @@ Handle<JSTypedArray> Factory::NewJSTypedArray(ExternalArrayType type,
   array->set_weak_next(buffer->weak_first_view());
   buffer->set_weak_first_view(*array);
   array->set_byte_offset(Smi::FromInt(0));
-  array->set_byte_length(buffer->byte_length());
+  Handle<Object> byte_length_handle =
+      NewNumberFromSize(length * GetExternalArrayElementSize(type));
+  array->set_byte_length(*byte_length_handle);
   Handle<Object> length_handle = NewNumberFromSize(length);
   array->set_length(*length_handle);
   Handle<ExternalArray> elements =