v8/test/mjsunit/compiler/materialize-mutable-heap-number.js

// Copyright 2017 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 C() {}
%CompleteInobjectSlackTracking(new C());

function f() {
  // Create a non-escaping object.
  var o = new C();
  // Add an out-of-object double property.
  o.x = 0.5;
  %DeoptimizeNow();
  return o.x + 0.25;
}

%PrepareFunctionForOptimization(f);
f();
f();
%OptimizeFunctionOnNextCall(f);
assertEquals(0.75, f());