text: // Copyright 2020 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 --turboprop --turboprop-dynamic-map-checks --opt
  // Flags: --no-always-opt
  
  function f(o) {
    return o.b;
  }
  
  var o = {a:10, b:20};
  var o1 = {a:10, b:20};
  var o2 = {a:10, b:20};
  var o3 = {a:10, b:20, c:30};
  %PrepareFunctionForOptimization(f);
  // Transition IC state to polymorphic.
  f(o);
  f(o3);
  %OptimizeFunctionOnNextCall(f);
  f(o);
  assertOptimized(f);
  f(o);
  
  // Deprecates O's map.
  o1.b = 10.23;
  // Deoptimizes but retains code.
  f(o1);
  assertOptimized(f);
  
  // Continues to use optimized code since deprecated map is still in the
  // feedback. ICs don't drop deprecated maps in the polymoprhic case.
  f(o);
  f(o);
  assertOptimized(f);
  