|  | // 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 load(obj){ | 
|  | return obj.x; | 
|  | } | 
|  |  | 
|  | %PrepareFunctionForOptimization(load); | 
|  | obj = {}; | 
|  | obj.x = 1; | 
|  |  | 
|  | //get mono feedback | 
|  | load(obj); | 
|  |  | 
|  | // optimize as mono | 
|  | %OptimizeFunctionOnNextCall(load); | 
|  | load(obj); | 
|  | assertOptimized(load); | 
|  | load(obj); | 
|  |  | 
|  | // change the object's representation. | 
|  | obj.x = 2.3; | 
|  | load(obj); | 
|  | // deoptimizes on a wrong map but retains the code | 
|  | assertOptimized(load); | 
|  |  | 
|  | // deoptimizes on the wrong handler. | 
|  | load(obj); | 
|  | assertUnoptimized(load); |