Collaborative Research: PPoSS: LARGE: Unifying Software and Hardware to Achieve Performant and Scalable Frictionless Parallelism in the Heterogeneous Future

开发并行性对于充分利用从电话到超级计算机的计算机系统至关重要。因此，它是当今大多数应用程序的固有特性，而且随着时间的推移，尤其是在硬件变得更加异构化的情况下，它正变得越来越重要。然而，编写有效和高性能的并行应用程序仍然是一个严峻的挑战。要同时实现高生产率和高性能，目前需要多名专家。该项目试图将这一点简化为一个普通的程序员。这个问题通常只通过以下两条路线中的一条来解决：“理论下降”，专注于高级并行语言和并行算法的理论和实践，或“体系结构上升”，专注于从硬件开始在多个层次上重新思考抽象。该项目的核心创新是(1)统一这两种方法，结合它们的优势来减少编写高性能并行程序所需的专业知识，以及(2)开发能够利用异类硬件的集成技术。要实现这些新颖性，需要设计一种“全栈”方法，以实现硬件/软件栈之间的并行性和创新。该项目的影响是(1)开发了极大地简化并行编程的技术，包括针对异类机器的编程，将其置于普通程序员的职权范围内；(2)开发了系统和教育材料，将这项技能传授给更广泛的受众，包括研究机构的学生。该项目的技术战略是通过一系列集成的程序中间表示(IR)和目标平台的硬件/软件能力，将允许清晰地表达和分析程序并行性的高级并行语言连接到异类、可扩展的硬件(使用FPGA建模)。这些表示的设计将避免当前阻碍所有级别优化的信息丢失(在编译器/运行时/操作系统/硬件堆栈中上下移动)。一种新的高级并行语言编译模型正在开发中，该模型广泛利用了现代编译器技术，但也避免了并行结构的“过早降低”和硬件和低级软件功能的“过早抽象”。正在制定衡量方法有效性的基准。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Exploiting parallelism is essential to making full use of computer systems, from phones to supercomputers. It is thus intrinsic to most applications today, and is becoming increasingly so with time, especially as hardware becomes more heterogeneous. Programming effective and performant parallel applications remains a serious challenge, however. Achieving both high productivity and high performance currently requires multiple experts. The project seeks to reduce this to an ordinary programmer. This problem is often approached along only one of two lines, "theory down", focusing on high-level parallel languages and the theory and practice of parallel algorithms, or "architecture up", focusing on rethinking abstractions at multiple layers, starting with the hardware. The project’s core novelties are (1) to unify these two approaches, combining their strengths to reduce the expertise needed to write performant parallel programs, and (2) to develop integrated techniques that can enable taking advantage of heterogeneous hardware. Realizing these novelties will require designing a "full-stack" approach to parallelism and innovation across the hardware/software stack. The project's impacts are (1) the development of techniques that dramatically simplify parallel programming, including for heterogeneous machines, putting it into the purview of the ordinary programmer, and (2) the development of systems and educational materials to teach this skill to broader audiences including students at the researchers' institutions.The technical strategy of the project is to bridge high-level parallel languages, which allow clean expression and analysis of program parallelism, to heterogeneous, extensible hardware (modeled using FPGAs) through an integrated series of intermediate representations (IRs) of a program and of the hardware/software capabilities of the target platform. The design of these representations will be geared to avoid the information loss (going both up and down the compiler/runtime/OS/hardware stack) that currently hampers optimization at all levels. A new compilation model for high-level parallel languages is being developed that extensively leverages modern compiler technology, but also avoids "premature lowering" of parallel constructs, and "premature abstraction" of hardware and low-level software features. Benchmarks are beinge developed to measure the effectiveness of the approach.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.