Store offset between fixed typed array base and data start in object

src/hydrogen.cc

 // 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.
 
 #include "src/hydrogen.h"
 
 #include <sstream>
 
 #include "src/v8.h"
 
@@ skipping 2440 matching lines @@
   HValue* checked_key = NULL;
   if (IsExternalArrayElementsKind(elements_kind) ||
       IsFixedTypedArrayElementsKind(elements_kind)) {
     checked_object = Add<HCheckArrayBufferNotNeutered>(checked_object);
 
     HValue* backing_store;
     if (IsExternalArrayElementsKind(elements_kind)) {
       backing_store = Add<HLoadNamedField>(
           elements, nullptr, HObjectAccess::ForExternalArrayExternalPointer());
     } else {
-      backing_store = elements;
+      HValue* external_pointer = Add<HLoadNamedField>(
+          elements, nullptr,
+          HObjectAccess::ForFixedTypedArrayBaseExternalPointer());
+      HValue* base_pointer = Add<HLoadNamedField>(
+          elements, nullptr,
+          HObjectAccess::ForFixedTypedArrayBaseBasePointer());
+      backing_store = AddUncasted<HAdd>(external_pointer, base_pointer,
+                                        Strength::WEAK, AddOfExternalAndTagged);
     }
     if (store_mode == STORE_NO_TRANSITION_IGNORE_OUT_OF_BOUNDS) {
       NoObservableSideEffectsScope no_effects(this);
       IfBuilder length_checker(this);
       length_checker.If<HCompareNumericAndBranch>(key, length, Token::LT);
       length_checker.Then();
       IfBuilder negative_checker(this);
       HValue* bounds_check = negative_checker.If<HCompareNumericAndBranch>(
           key, graph()->GetConstant0(), Token::GTE);
       negative_checker.Then();
@@ skipping 7540 matching lines @@
 #endif
 
   AddStoreMapConstant(elements, fixed_typed_array_map);
 
   Add<HStoreNamedField>(elements,
       HObjectAccess::ForFixedArrayLength(),
       length);
   Add<HStoreNamedField>(
       elements, HObjectAccess::ForFixedTypedArrayBaseBasePointer(), elements);
 
+  Add<HStoreNamedField>(
+      elements, HObjectAccess::ForFixedTypedArrayBaseExternalPointer(),
+      Add<HConstant>(ExternalReference::fixed_typed_array_base_data_offset()));
+
   HValue* filler = Add<HConstant>(static_cast<int32_t>(0));
 
   if (initialize) {
     LoopBuilder builder(this, context(), LoopBuilder::kPostIncrement);
 
+    HValue* backing_store = AddUncasted<HAdd>(
+        Add<HConstant>(ExternalReference::fixed_typed_array_base_data_offset()),
+        elements, Strength::WEAK, AddOfExternalAndTagged);
+
     HValue* key = builder.BeginBody(
         Add<HConstant>(static_cast<int32_t>(0)),
         length, Token::LT);
-    Add<HStoreKeyed>(elements, key, filler, fixed_elements_kind);
+    Add<HStoreKeyed>(backing_store, key, filler, fixed_elements_kind);
 
     builder.EndBody();
   }
   return elements;
 }
 
 
 void HOptimizedGraphBuilder::GenerateTypedArrayInitialize(
     CallRuntime* expr) {
   ZoneList<Expression*>* arguments = expr->arguments();
@@ skipping 3279 matching lines @@
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 }  // namespace internal
 }  // namespace v8