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

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可能是有益的，但它们不能直接应用于用户定义的类型，因为它们的正确性不能先验地确定。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，但是如果必须逐个类型地扩展编译器，这种方法就会变得很繁琐。更强大的方法是启用通用的编译器优化，也就是说，它可以应用于任何类型（内置的或用户定义的），满足基本的语义需求。智力价值——正式的概念定义。我们将把基于概念的优化与我们正在进行的概念形式化和泛型编程的研究结合起来。-概念的语言支持。基于概念的优化将利用并告知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。-编译器对概念的支持。我们最初将概念整合到GNU c++编译器中的努力将被扩展，以支持基于概念的优化。-基于概念的优化。我们将利用泛型编程机制来定义使用概念的优化，以便这样的优化应用于用户定义的类型，只需声明类型模型（即，满足特定概念的需求）。-部署和库演进。选定的泛型库，包括标准模板库、Boost图形库和矢量、信号和图像处理库，将被升级，以利用泛型编程的语言扩展和基于概念的优化。评估套件。我们将收集一组高级基准的优化，这些基准可用于评估基于概念的优化。在这方面，一个重要的基准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。更广泛的影响——对支持泛型编程的主流编程语言（如c++、c#和Java）的未来发展及其标准库的直接影响。-与语言和编译器实现者合作，并努力引入更好地支持泛型编程的语言特性。在这些语言中对泛型编程的支持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。-该项目将直接培养新兴泛型编程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我们教授的研究生编程课程中，并（像我们过去所做的那样）被纳入我们编写的教科书中。

Background A 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. We will integrate concept-based optimization with our on-going research on formalization of concepts and 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. Our initial efforts incorporating concepts into the GNU C++ compiler will be extended to support concept-based optimizations. - Concept-based optimizations. We 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. We will collect optimizations for a suite of high-level benchmarks that can be used to evaluateconcept-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 Impact - 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. - Collaborate with language and compiler implementors, and work to introduce language features that better support generic programming. -Support for generic programming in these languages 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 courses that we teach and (as we have done in the past) into textbooks that we write.