Fix handling of potential string additions in hydrogen.

R=titzer@chromium.org
TEST=mjsunit/regress/regress-3476
BUG=v8:3476
LOG=N

Review URL: https://codereview.chromium.org/423083004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@22677 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen.cc

@@ -10240,7 +10240,9 @@ HValue* HGraphBuilder::BuildBinaryOperation(
 
   bool maybe_string_add = op == Token::ADD &&
                           (left_type->Maybe(Type::String()) ||
-                           right_type->Maybe(Type::String()));
+                           left_type->Maybe(Type::Receiver()) ||
+                           right_type->Maybe(Type::String()) ||
+                           right_type->Maybe(Type::Receiver()));
 
   if (left_type->Is(Type::None())) {
     Add<HDeoptimize>("Insufficient type feedback for LHS of binary operation",

test/mjsunit/regress/regress-3476.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
+
+function MyWrapper(v) {
+  return { valueOf: function() { return v } };
+}
+
+function f() {
+  assertEquals("truex", true + "x");
+  assertEquals("truey", true + new String("y"));
+  assertEquals("truez", true + new MyWrapper("z"));
+
+  assertEquals("xtrue", "x" + true);
+  assertEquals("ytrue", new String("y") + true);
+  assertEquals("ztrue", new MyWrapper("z") + true);
+}
+
+f();
+f();
+%OptimizeFunctionOnNextCall(f);
+f();