v8/test/mjsunit/compiler/deopt-accessors4.js

// Copyright 2016 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

var o = {v:1};
var deopt = false;

Object.defineProperty(o, "x", {
  get: function() { return this.v; },
  set: function(v) {
    this.v = v;
    if (deopt) {
      %DeoptimizeFunction(foo);
    }
  }
});

function foo(o) {
  var x = "x";
  return ++o[x];
}

%PrepareFunctionForOptimization(foo);
assertEquals(2, foo(o));
assertEquals(3, foo(o));
%OptimizeFunctionOnNextCall(foo);
deopt = true;
assertEquals(4, foo(o));