基于即时编译的GNU Octave性能优化

GNU Octave是一款数值计算软件,具有免费、开源以及几乎完全兼容MATLAB语言的优点。然而,Octave内置的基于LLVM的实验性即时编译器仅支持对少部分代码进行即时编译,无法有效解决Octave效率低下的问题。基于Octave即时编译器探究对Octave的性能优化方案,从工作原理角度出发,对该即时编译器整体工作原理和其中的类型推断系统进行分析;从工作现状角度出发,评估该即时编译器对Octave代码的适用范围和性能提升效果;针对该即时编译器的内置函数调用、索引运算与算术逻辑运算进行特性修复和功能新增,使Octave获得性能提升。实验结果表明,基于即时编译器的优化方案有效扩展了即时编译器的适用范围,为Octave代码执行带来56~283倍不等的性能提升。此外,总结了该即时编译器中存在的16类缺陷,对进一步优化Octave性能具有参考意义。     

A transportable extendable compiler

This report describes the development of a transportable extendable self-compiler for the language SIMPL-T. SIMPL-T is designed as the base language for a family of languages. The structure of the SIMPL-T compiler and its transportable bootstrap are described. In addition, the procedures for generating a compiler for a new machine and for boot-strapping the new compiler on to the new machine are demonstrated.     

The design of a pascal compiler

The development of a compiler for the programming language PASCAL¹ is described in some detail. Design decisions concerning the layout of program and data, the organization of the compiler including its syntax analyser, and the over-all approach to the project are discussed. The compiler is written in its own language and was implemented for the CDC 6000 computer family. The reader is expected to be familiar with Reference 1.     

Andorra-I compilation

Andorra-I is an experimental parallel Prolog system which transparently exploits both dependent and-parallelism and or-parallelism. One of the main components of Andorra-I is its preprocessor. In order to obtain efficient execution of programs in Andorra-I, the preprocessor includes a compiler for Andorra-I. The compiler includes a determinacy analyser and a clause compiler, and generates code for a specialised abstract machine. In this paper we discuss the main issues in the Andorra-I compiler, presenting its abstract instruction set and describing the algorithms used in its implementation.     

可信编译理论及其核心实现技术:研究综述

编译器是重要的系统软件之一,高级语言编写的软件都必须经过编译器的编译才能成为可执行程序。编译器的可信性对于整个计算机系统而言具有非常关键的意义,如果编译器不可信,则很难保证系统所运行软件的可信性。可信编译是指编译器在保证编译正确的同时提供相应的机制保证编译对象的可信性,对可信编译理论和技术的研究具有重要理论意义和实用前景。阐述了可信编译器的概念,介绍了编译过程正确性的形式化定义,对可信编译的主要研究进行了概括。在全面分析可信编译研究现状的基础上,从编译器自身可信性和确保编译对象可信性两个方面,对可信编译器设计和实现的相关理论和方法进行了分类和总结。最后,讨论了可信编译有待解决的问题和未来的研究方向。     

A Data-Parallel FP Compiler

In data-parallel programming, operations are performed simultaneously on all elements of large data structures. Backus′s FP functional language promotes this view. FP provides a large set of data rearrangement primitives, and a useful set of functional combining forms that are applied to entire data structures. We describe an FP compiler that generates programs capable of exploiting data-parallelism. The FP compiler deduces the type and shape of objects through type inference, and generates efficient parallel implementations of combining forms. In addition, the compiler determines the effects of data rearrangement functions at compile-time, thereby avoiding creation of large intermediate data structures, and reducing interprocessor communication overhead. FP and its compiler are formally specified, reducing ambiguity concerning constructs of the language and results of the compiler. Performance and speed-ups achieved from our compilation and optimization techniques are demonstrated with timings from a prototype implementation on the Connection Machine CM-2.     

Logic programming and compiler writing

The concept of ‘logic programming’, and its practical application in the programming language Prolog, are explained from first principles. The ideas are illustrated by describing in detail one sizable Prolog program which implements a simple compiler. The advantages and practicability of using Prolog for ‘real’ compiler implementation are discussed.     

A comparison of programming languages for software engineering

Four programming languages (Fortran, Cobol, Jovial and the proposed DoD standard) are compared in the light of modern ideas of good software engineering practice. The comparison begins by identifying a core for each language that captures the essential properties of the language and the intent of the language designers. These core languages then serve as a basis for the discussion of the language philosophies and the impact of the language on gross program organization and on the use of individual statements.     

Action semantics-directed prototyping

We present a methodology for compiler synthesis based on Mosses-Watt's action semantics. Each action in action semantics notation is assigned specific “analysis functions”, such as a typing function and a binding-time function. When a language is given an action semantics, the typing and binding-time functions for the individual actions compose into typing and binding-time analyses for the language; these are implemented as the type checker and static semantics processor, respectively, in the synthesized compiler. Other analyses can be similarly formalized and implemented. We show a sample language semantics and its synthesized compiler, and we describe the compiler synthesizer that we have developed.     

Design recovery for distributed systems

Two factors limit the utility of reverse engineering technology for many distributed software systems. First, with the exception of tools that support Ada and its explicit tasking constructs, reverse engineering tools fail to capture information concerning the flow of information between tasks. Second, relatively few reverse engineering tools are available for programming languages in which many older legacy applications were written (e.g., Jovial, CMS-2, and various assembly languages). We describe approaches that were developed for overcoming these limitations. In particular, we have implemented an approach for automatically extracting task flow information from a command and control system written in CMS-2. Our approach takes advantage of a small amount of externally provided design knowledge in order to recover design information relevant to the distributed nature of the target system