Fix for a smi stores optimization on x64 with a regression test.

BUG=345715
LOG=N
R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/178833002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@19535 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -9924,9 +9924,11 @@ void HOptimizedGraphBuilder::BuildEmitInObjectProperties(
         Add<HStoreNamedField>(double_box, HObjectAccess::ForHeapNumberValue(),
                               Add<HConstant>(value));
         value_instruction = double_box;
-      } else if (representation.IsSmi() && value->IsUninitialized()) {
-        value_instruction = graph()->GetConstant0();
-        // Ensure that Constant0 is stored as smi.
+      } else if (representation.IsSmi()) {
+        value_instruction = value->IsUninitialized()
+            ? graph()->GetConstant0()
+            : Add<HConstant>(value);
+        // Ensure that value is stored as smi.
         access = access.WithRepresentation(representation);
       } else {
         value_instruction = Add<HConstant>(value);

test/mjsunit/regress/regress-crbug-345715.js

+// 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.
+
+// Flags: --allow-natives-syntax
+
+a = {y:1.5};
+a.y = 0;
+b = a.y;
+c = {y:{}};
+
+function f() {
+  return 1;
+}
+
+function g() {
+  var e = {y: b};
+  var d = {x:f()};
+  var d = {x:f()};
+  return [e, d];
+}
+
+g();
+g();
+%OptimizeFunctionOnNextCall(g);
+assertEquals(1, g()[1].x);