ST-CRTS: Collaborative Research: Lifting Compiler Optimizations via Generic Programming

背景典型的编译器被设计为将其优化应用于其正在编译的语言的内置类型。尽管内置的通用优化通常是有益的，但它们不能直接应用于用户定义的类型，因为它们的正确性无法事先确定。扩展编译器以优化某些特定的用户定义类型对于该特定类型是有用的，但如果必须在逐个类型的基础上扩展编译器，则这种方法会变得很麻烦。一种更强大的方法是启用泛型的编译器优化，即可以应用于满足基本语义要求的任何类型(内置或用户定义的)。PI建议将基于概念的优化与他们对泛型编程的概念形式化的研究相结合。-概念的语言支持。基于概念的优化将利用我们正在进行的对概念和泛型编程的直接语言支持的研究，并为其提供信息。PI最初将概念整合到GNU C++编译器中的努力将被扩展到支持基于概念的优化。PI将利用泛型编程机制来定义使用概念的优化，以便这样的优化适用于用户定义的类型，只需声明类型模型(即，满足特定概念的要求)。-部署和库演变。选定的类型库，包括标准模板库、Boost图形库以及矢量、信号和图像处理库，将进行升级，以利用泛型编程的语言扩展并利用基于概念的优化。-评估套件。PI将收集一套高级基准的优化，这些基准可用于评估基于概念的优化。这方面的一个重要基准将是证明泛型优化在应用于内置类型时提供与传统类型特定优化相同的性能优势。广泛影响拟议的研究将对支持泛型编程的主流编程语言(例如，C++、C#和Java)及其标准库的未来发展产生直接影响。-支持这些语言的泛型编程，这将提供有关用户定义类型的有价值的高级信息，使高级和基于概念的优化更广泛地适用。该项目将直接培训通用编程新兴领域的研究生和博士后研究人员。我们的研究结果将被整合到研究生编程课程和教科书中。

BackgroundA typical compiler is designed to apply its optimizations to built-in types of the language it is compiling. Although built-in general-purpose optimizations might be generally beneficial, they cannot be directly applied to user-defined types because their correctness cannot be determined a priori. Extending a compiler to optimize some particular userdefined type would be useful for that particular type, but this approach becomes burdensome if the compiler must be extended on a type-by-type basis. A more powerful approach would be to enable compiler optimizations that are generic, i.e., that can be applied to any type (built-in or user-defined) that meets fundamental semantic requirements.Intellectual Merit-Formal concept definitions. The PIs propose to integrate concept-based optimization with their research on formalization of concepts for generic programming.-Language support for concepts. Concept-based optimization will leverage and inform our on-going research on direct language support for concepts and generic programming.-Compiler support for concepts. The PI's initial efforts incorporating concepts into the GNU C++ compiler will be extended to support concept-based optimizations.- Concept-based optimizations. The PI's will leverage generic programming mechanisms to define optimizations using concepts so that such optimizations apply to user-defined types, simply by stating that the types model (i.e., meetthe requirements of) particular concepts.-Deployment and library evolution. Selected generic libraries, including the Standard Template Library, the Boost Graph Library, and the Vector, Signal, and Image Processing Library will be upgraded to take advantage of language extensions for generic programming and to take advantage of concept-based optimization.-Evaluation suite. The PIs will collect optimizations for a suite of high-level benchmarks that can be used to evaluate concept-based optimizations. An important benchmark in this regard will be to demonstrate that generic optimizations offer the same performance benefits when applied to built-in types as do traditional type-specific optimizations.Broader ImpactThe proposed research will have:- Direct impact on the future development of mainstream programming languages that support generic programming (e.g., C++, C#, and Java), and on their standard libraries. -Support for generic programming in these languages that will provide valuable high-level information about user-defined types,making high-level and concept-based optimization more widely applicable. This project will directly train graduate students and post-doctoral researchers in the emerging field of generic programming. Results from our research will be integrated into graduate programming coursesand into textbooks.