Optimizing Parallel Programs

许多常见的编译器优化都需要对程序内的数据流进行精确分析。该项目将扩展数据流分析算法，将其应用于显式并行命令式语言。这项工作的基础将是程序的静态单一赋值(SSA)形式，它是为顺序语言开发的。这个项目将使用嵌套的图形中间表示法来描述程序的顺序和并行部分。将向SSA表单添加新的构造，以描述显式并行程序产生的并行性和不确定性。用于生成程序的SSA表示的算法将被修改以处理并行构造。将开发新的算法来发现并行代码中的潜在异常。已经开发了一个原型编译器(具有先前的NSF支持)，它可以识别新兴的ANSI标准并行Fortran语法。为这个项目开发的所有算法都将在该系统中实现。

Many common compiler optimizations require precise analysis of the flow of data within a program. This project will extend the data flow analysis algorithms to apply them to explicitly parallel imperative languages. The basis for this work will be the Static Single Assignment (SSA) form of a program, which was developed for sequential languages. This project will use a nested graph intermediate representation to describe the sequential and parallel parts of the program. New constructs will be added to the SSA form to describe the parallelism and nondeterminism that arises from explicitly parallel programs. The algorithms for generating the SSA representation of a program will be modified to handle the parallel constructs. New algorithms will be developed to find potential anomalies in parallel code. A prototype compiler has been developed (with prior NSF support) that recognizes the emerging ANSI standard parallel Fortran syntax. All of the algorithms developed for this project will be implemented in that system.