XPS: EXPL: CCA: A Framework for Portable Parallel Performance

由于无法以历史速度提高计算机处理器性能，微处理器行业已转向在每台计算机中捆绑更多的处理器内核。 虽然额外的处理器核心为每台计算机提供了更多的处理能力，但利用这种能力的负担转移到了程序员身上。 更糟糕的是，每台计算机中的内核并不完全相同，每种计算机型号可能具有不同数量和混合的内核。 为一台计算机优化的软件可能在另一台计算机上表现不佳，让程序员为每种计算机模型进行优化是不切实际的。 该项目旨在通过改变程序员为这些系统编写代码的方式，并让计算机针对其特定配置优化软件来克服这些问题。 该项目将研究如何传递更丰富的信息，以帮助计算机最好地优化运行在其上的软件。该项目有可能从根本上改变程序员为现代体系结构开发软件的方式，从而减轻他们为不同系统优化代码的艰巨任务。 任何软件的用户-从计算科学家到家庭桌面用户-都将体验到性能的提高和新应用程序的更快部署。所提出的软件接口必须以一种可自动分析的方式表示代码，并且在运行时高度服从自动代码转换。该项目将探索许多设计，包括以单一静态分配（SSA）形式显式编码寄存器依赖，静态确定并将内存依赖信息编码到指令中，以及使用富有表现力的代码布局方案来使运行时分析和优化更有效。与此设计空间探索相一致，将开发各种运行时优化，这些优化将为特定计算机定制软件执行，同时还针对动态变化的用户需求（例如执行速度和能耗）进行优化。 软件界面和运行时优化的协同设计将允许确定要包括在界面中的最佳信息集。 该项目还旨在为开发人员创建工具（编译器，汇编器和架构模拟器），以使其他人能够使用和评估它。PI将继续建立在他过去在促进多样性和教育推广工作方面的成功基础上。 他每年将接待几名本科生研究人员，与研究生导师合作。 他还将继续将目前的研究成果纳入本科和研究生课程。

Unable to increase computer processor peformance growth at the historic rate, the microprocessor industry has shifted to bundling more processor cores in each computer. While additional processor cores puts more processing power in each computer, the burden of making use of this power shifts to the programmer. To make matters worse, the cores in each computer are not all the same and each computer model may have a different number and mix of cores. Software optimized for one computer may perform poorly for another, and having programmers optimize for each computer model is not practical. This project intends to overcome these problems by changing the way programmers write code for these systems and having the computer optimize the software for its specific configuration. The project will study ways to convey the richer set of information necessary to help computers best optimize the software running upon it. This project has the potential to fundamentally alter how programmers develop software for modern architectures, relieving them of the arduous task of optimizing their code for different systems. Users of any software---from computational scientists to home desktop users---would experience an increase in performance and faster deployment of new applications.The proposed software interface must represent code in a way that is automatically analyzable and highly amenable to automatic code transformations at runtime. The project will explore many designs, including explicitly encoding register dependences in Single Static Assignment (SSA) form, statically determining and encoding memory dependency information into instructions, and using an expressive code layout scheme to make runtime analysis and optimization more efficient. In concert with this design space exploration, various runtime optimizations will be developed which will customize the software execution for the specific computer while also optimizing for dynamically changing user desires such as execution speed and energy consumption. The synergistic design of the software interface and runtime optimizations will allow determination of the optimal set of information to include in the interface. This project also aims to create tools for developers (compiler, assembler, and architectural simulator) to enable others to use and evaluate it.The PI will keep building on his past successes in fostering diversity and educational outreach efforts. He will host several undergraduate student researchers each year, teaming them with graduate student mentors. He will also continue to incorporate current research results into undergraduate and graduate courses.