HSubAllocatedObject instruction allows hydrogen code to carve up

src/x64/lithium-codegen-x64.cc

 // 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 3930 matching lines @@
       isolate()->builtins()->ArrayConstructCode();
   CallCode(array_construct_code, RelocInfo::CONSTRUCT_CALL, instr);
 }
 
 
 void LCodeGen::DoCallRuntime(LCallRuntime* instr) {
   CallRuntime(instr->function(), instr->arity(), instr);
 }
 
 
+void LCodeGen::DoInnerAllocatedObject(LInnerAllocatedObject* instr) {
+  Register result = ToRegister(instr->result());
+  Register base = ToRegister(instr->base_object());
+  __ lea(result, Operand(base, instr->offset()));
+}
+
+
 void LCodeGen::DoStoreNamedField(LStoreNamedField* instr) {
   Register object = ToRegister(instr->object());
   Register value = ToRegister(instr->value());
   int offset = instr->offset();
 
   if (!instr->transition().is_null()) {
     if (!instr->hydrogen()->NeedsWriteBarrierForMap()) {
       __ Move(FieldOperand(object, HeapObject::kMapOffset),
               instr->transition());
     } else {
@@ skipping 1879 matching lines @@
                                FixedArray::kHeaderSize - kPointerSize));
   __ bind(&done);
 }
 
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64