Using Declarative Machine Descriptions in a Retargetable Optimizing Compiler

计算机程序是用高级编程语言编写的，但要运行，它必须被翻译成机器语言。每种机器——台式电脑、手机、掌上电脑——都有不同的机器语言，需要不同的翻译人员。目前，每个翻译人员必须由一位既精通翻译又精通机器语言的专家撰写。该项目将开发出一种方法，使翻译人员可以在没有这种双重专业知识的情况下进行写作。一个只知道机器的专家会写一个陈述性的描述来说明机器是做什么的。该项目的软件将分析这一描述，并机械地生成组件，供只懂翻译的专家使用。由于这种方法非常依赖于描述的正确性，因此项目还将开发用于机械地检查描述是否与实际硬件一致的技术。这些描述和分析将使机器专家的工作能够在许多不同的翻译器（和其他应用程序）中重用，并且翻译专家的工作可以很容易地应用于许多不同的机器。新机器的翻译器将比现在开发得更快、更可靠、更省力。

A computer program is written in a high-level *programming* *language*, but to be run, it must be translated into a *machine* *language*. Each kind of machine---desktop computer, cell phone, handheld computer---has a different machine language and needs a different translator. At present, each translator must be written by an expert who specializes *both* in translation *and* in machine language. This project will develop methods by which a translator can be written without such double expertise. An expert who knows only about the machine will write a *declarative* description that says what the machine does. The project's software will analyze this description and mechanically produce components to be used by an expert who knows only about translation. Because this approach relies crucially on the description's being correct, the project will also develop techniques for mechanically checking that the description is consistent with real hardware. The descriptions and the analysis thereof will enable the machine expert's work to be reused in many different translators (and other applications) and the translation expert's work to be readily applied to many different machines. Translators for new machines will be developed more quickly, more reliably, and with less effort than at present.