CAREER: A Semantic Framework for Static and Dynamic Optimization

职业：静态和动态优化的语义框架

• 批准号: 9624932
• 负责人: Rebecca Parsons
• 金额: $ 20万
• 依托单位: The University of Central Florida Board of Trustees
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9624932&HistoricalAwards=false
• 关键词: CAREER; Semantic; Framework; Static; Dynamic

Acceptance of an object-oriented approach to scientific computing is being hindered by the performance differential between programs written in traditional languages and those written in object-oriented languages. These performance issues stem from the limitations on static dependence analysis and compiler optimization posed by the presence of objects. An approach to increasing the degree of optimization in object-oriented environments is incorporating information about the object semantics and performing runtime optimizations. As proved true for compiler optimization using static dependence information,informal semantics and intuition are inadequate. A semantic foundation for optimization which includes support for dynamic dependence and for the richer data types exploited in object-oriented languages provides an important foundation for advancing compiler research. The semantic model studied in this research is intended to unify reasoning both in the compiler (static) environment and the runtime (dynamic)environment. Support for dynamic object creation and even dynamic class definition can be considered in a setting exploiting both static and dynamic dependence information. The resulting model, utilizing tools such as denotational semantics and equational calculi, will allow the creation of automated tools to assist in the development of advanced compiler optimizations with the additional formal assurances that these optimizations do not alter the meaning of the program. The computational demands posed by computational biology provide another realistic setting within which to study the complexities of object-oriented parallel and distributed program development and the concomitant optimization needs for language systems. The educational goals of this research are to both alter the programming languages and compiler curricula to address, at all levels, issues of semantics, optimization, and the degree to which each affect the other. The computational biology work provides a promising framework within which to study these issues. Thus, the computational biology curricula is being developed in parallel with the languages work. This research is expected to contribute to an understanding of the nature of program dependences; how different language constructs and program usage contribute to different patterns of dependence; and how these patterns can be exploited in language design or in language translation. Work in this area has already uncovered unsuspected connections between lazy evaluation and imperative languages. Further study should provide insight into relationships among languages in the context of their interactions at runtime. A goal of this research is to support the mixing of languages without sacrificing the performance of the program, allowing the programmer to select the most appropriate language for the individual parts of a problem. The fundamental notion of program dependence is a natural basis on which to construct a system supporting this style of programming. ***

用传统语言编写的程序与用面向对象语言编写的程序之间的性能差异阻碍了对科学计算的面向对象方法的接受。这些性能问题源于对象的存在对静态依赖分析和编译器优化的限制。 在面向对象环境中提高优化程度的一种方法是合并有关对象语义的信息并执行运行时优化。 正如使用静态依赖信息进行编译器优化所证明的那样，非正式语义和直觉是不够的。 优化的语义基础包括对动态依赖和面向对象语言中使用的更丰富的数据类型的支持，为推进编译器研究提供了重要的基础。 本研究中研究的语义模型旨在统一编译器（静态）环境和运行时（动态）环境中的推理。 在利用静态和动态依赖信息的设置中可以考虑支持动态对象创建甚至动态类定义。由此产生的模型利用指称语义和方程演算等工具，将允许创建自动化工具来协助高级编译器优化的开发，并额外正式保证这些优化不会改变程序的含义。 计算生物学提出的计算需求提供了另一个现实的环境，在该环境中研究面向对象的并行和分布式程序开发的复杂性以及随之而来的语言系统的优化需求。 这项研究的教育目标是改变编程语言和编译器课程，以解决各个级别的语义、优化以及彼此影响的程度问题。计算生物学工作为研究这些问题提供了一个有前途的框架。 因此，计算生物学课程是与语言工作并行开发的。 这项研究预计将有助于理解程序依赖性的本质；不同的语言结构和程序使用如何导致不同的依赖模式；以及如何在语言设计或语言翻译中利用这些模式。 该领域的工作已经揭示了惰性求值和命令式语言之间意想不到的联系。 进一步的研究应该可以深入了解语言在运行时交互的背景下之间的关系。 这项研究的目标是在不牺牲程序性能的情况下支持语言混合，从而允许程序员为问题的各个部分选择最合适的语言。程序依赖性的基本概念是构建支持这种编程风格的系统的自然基础。 ***