- Change the layout of external typed array objects to avoid the extra indirection when accessing e…

runtime/vm/intermediate_language_x64.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_X64.
 #if defined(TARGET_ARCH_X64)
 
 #include "vm/intermediate_language.h"
 
 #include "lib/error.h"
@@ skipping 1027 matching lines @@
     Register result = locs()->out().reg();
     Address element_address = index.IsRegister()
         ? FlowGraphCompiler::ExternalElementAddressForRegIndex(
             class_id(), result, index.reg())
         : FlowGraphCompiler::ExternalElementAddressForIntIndex(
             class_id(), result, Smi::Cast(index.constant()).Value());
     if (index.IsRegister()) {
       __ SmiUntag(index.reg());
     }
     __ movq(result,
-            FieldAddress(array, ExternalUint8Array::external_data_offset()));
-    __ movq(result,
-            Address(result, ExternalByteArrayData<uint8_t>::data_offset()));
+            FieldAddress(array, ExternalUint8Array::data_offset()));
     __ movzxb(result, element_address);
     __ SmiTag(result);
     if (index.IsRegister()) {
       __ SmiTag(index.reg());  // Re-tag.
     }
     return;
   }
 
   FieldAddress element_address = index.IsRegister() ?
       FlowGraphCompiler::ElementAddressForRegIndex(
@@ skipping 1933 matching lines @@
                          PcDescriptors::kOther,
                          locs());
   __ Drop(2);  // Discard type arguments and receiver.
 }
 
 }  // namespace dart
 
 #undef __
 
 #endif  // defined TARGET_ARCH_X64