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Inline caching is an optimization technique employed by some language runtimes, and first developed for Smalltalk.〔 The goal of inline caching is to speed up runtime method binding by remembering the results of a previous method lookup directly at the call site. Inline caching is especially useful for dynamically typed languages where most if not all method binding happens at runtime and where virtual method tables often cannot be used. == Runtime method binding == The following ECMAScript function receives an object, invokes its toString-method and displays the results on the page the script is embedded in. function dump(obj) Since the type of the object is not specified and because of potential method overloading, it is impossible to decide ahead of time which concrete implementation of the toString-method is going to be invoked. Instead, a dynamic lookup has to be performed at runtime. In language runtimes that do not employ some form of caching, this lookup is performed every time a method is invoked. Because methods may be defined several steps down the inheritance chain, a dynamic lookup can be an expensive operation. To achieve better performance, many language runtimes employ some form of non-inline caching where the results of a limited number of method lookups are stored in an associative data structure. This can greatly increase performance, provided that the programs executed are "cache friendly" (i.e. there is a limited set of methods that is invoked frequently). This data structure is typically called the ''first-level method lookup cache''.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Inline caching」の詳細全文を読む スポンサード リンク
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