XPS: Full: FP: Collaborative Research: Sphinx: Combining Data and Instruction Level Parallelism through Demand Driven Execution of Imperative Programs

题目：XPS: Full: FP：协作研究：Sphinx：通过需求驱动的命令式程序执行来结合数据和指令级并行性提高处理器的性能以满足现有和新出现的工作负载的需求变得越来越困难。最近的重点是通过使用多核处理器和图形处理单元来提高性能。然而，这些处理器仍然难以编程，并且不灵活，无法适应给定程序中可用并行性的动态变化。尽管计算机体系结构和编程语言社区不断创新，并在更好的可编程性和更好的设计方面取得了重要进展，但并行编程本质上是昂贵的，容易出错，而且程序的自动并行化并不总是可行或有效的。该项目的智力优势在于开发了一种新的程序执行范式，建立了关键的编译器和微体系结构机制，以便我们可以设计出可以使用现有编程语言轻松编程的处理器，同时超越现有并行计算机的性能。该项目更广泛的意义和重要性是广泛的：这种处理器的部署将推动科学和商业各个领域的计算极限。所考虑的执行范例是以前未探索过的执行模型，即命令式程序（DDE）的需求驱动执行。DDE范例建立在坚实的理论框架之上，并承诺有效地交付非常高级别的细粒度并行性。这种并行性是从用命令式语言（如C）编写的程序中提取出来的，它是通过一种有效的编译器体系结构协作机制实现的，该机制使用一种通用的、单赋值形式来表示程序。DDE处理器可以比现有的超标量处理器更有效地提取指令级并行性，因为该范式不需要动态依赖检查。与当前的超标量处理器相比，这样的处理器可以并行获取、缓冲和执行更多的指令。由于其依赖驱动的指令获取和执行，该范式导致了极具可伸缩性的设计，因为通信是自然本地化的，同步是模型中固有的。传统的线程级并行性（TLP）与DDE是正交的，因此DDE设计可以同时利用ILP和TLP。因此，DDE体系结构代表了非常有前途的极端规模机器的构建块。

Title: XPS: Full: FP: Collaborative Research: Sphinx: Combining Data and Instruction Level Parallelism through Demand Driven Execution of Imperative ProgramsIt has become increasingly difficult to improve the performance of processors so that they can meet the demands of existing and emerging workloads. Recent emphasis has been towards enhancing the performance through the use of multi-core processors and Graphics Processing Units. However, these processors remain difficult to program and inflexible to adapt to dynamic changes in the available parallelism in a given program. Although the computer architecture and programming language community continues to innovate and make important gains towards better programmability and better designs, it remains that parallel programming is inherently costly and error prone, and automatic parallelization of programs is not always feasible or effective. The intellectual merits of this project are the development of a new program execution paradigm and the establishment of critical compiler and micro-architecture mechanisms so that we can design processors that can be easily programmed using existing programming languages and at the same time surpass the performance of existing parallel computers. The project's broader significance and importance are wide-spread: the deployment of such processors will push the limits of computation in every field of science and commerce.The execution paradigm under consideration is a previously unexplored execution model, the demand-driven execution of imperative programs (DDE). The DDE paradigm rests on a solid theoretical framework and promises to efficiently deliver very high-levels of fine-grain parallelism. This parallelism is extracted from a program written in an imperative language such as C, and it is realized by means of an effective compiler-architecture collaboration mechanism using a common, single-assignment form for the program representation. DDE processors can extract instruction-level parallelism much more efficiently than existing superscalar processors as the paradigm does not require dynamic dependency checking. Such processors can fetch, buffer, and execute many more instructions in parallel than current superscalar processors. Owing to its dependence-driven instruction fetching and execution, the paradigm leads to extremely scalable designs, as the communication is naturally localized and synchronization is inherent in the model. Conventional thread-level parallelism (TLP) is orthogonal to DDE, and thus DDE designs can exploit both ILP and TLP. DDE architectures thus represent promising building blocks for extreme-scale machines.