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Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
In the Tenth Turing Lecture, Allen Newell and Herbert Simon state that “Symbols lie at the root of intelligent action...” [43]. To design and produce intelligent computing systems, it follows that systems capable of processing symbols are required. Such computers will adhere to a model of computation based on what Newell and Simon term formal symbol systems. The intent in this book is to develop the principles by which high performance symbolic processors can be designed.
T. P. Dobry

Chapter 2. An Abstract Prolog Machine

Abstract
In 1977 David Warren described an instruction set and execution model for compiled Prolog [63]. This design was later modified and provided as an abstract machine specification which has become know as the Warren Abstract Machine (WAM) [57, 64]. The architecture described in this book extends the WAM and provides a description of the resulting machine and its implementation in hardware.
T. P. Dobry

Chapter 3. A Modified WAM

Abstract
This Chapter discusses the evolution of the Warren Abstract Machine described in Chapter 2 toward a physical machine, the Prolog Machine, PLM, described in Chapter 4. Given the instruction set of the WAM and the data types on which it processes, specific representations for both code and data are first described. Then new instructions and enhancements of old instructions are proposed. As part of this discussion the issue of built-in predicates in Prolog is identified as one of the major missing elements in the WAM specification and is addressed as a prominent feature of the PLM. Finally, some of the issues of compiling Prolog to run on the PLM are discussed.
T. P. Dobry

Chapter 4. The Architecture Becomes a Machine

Abstract
The previous Chapter provided the specification for the Instruction Set Architecture (ISA) of the PLM. This Chapter realizes the ISA by defining the microarchitecture of the PLM and describing the physical hardware which implements that microarchitecture. The next Chapter discusses and analyses the projected performance.
T. P. Dobry

Chapter 5. The Experiment

Abstract
The PLM is an experiment in the design of a specialized processor for Prolog and its implementation in hardware. This Chapter describes the tests used to evaluate the effectiveness of the design features and hardware of the PLM described in Chapter 4. The methodology of the experiment is first described. Results of the experiment presented in this Chapter were generated from the simulators for the PLM. Two levels of simulation were performed: Level 1 at the ISA Level and Level 2 at the Register Transfer Level. The simulators are described together with the simplifying assumptions made in their implementation. The set of Benchmark programs used to evaluate the PLM is briefly described here. An analysis of the results of the experiments is provided including the effects of cdr-coding, environment trimming, sidetracking, and host memory and processing speeds. A case study of variations on compiling code for the PLM is provided as well as an analysis and critique of the PLM data path and microcode.
T. P. Dobry

Chapter 6. Conclusions

Abstract
The previous chapters have developed a CISC architecture for the efficient execution of Prolog programs. The model for Prolog execution discussed in Chapter 1 was shown in Chapter 2 to be efficiently implemented by a concise, high level instruction set for an abstract machine proposed by Warren. In Chapter 3 extensions to the instruction set were proposed to provide the complete functionality of the Prolog language. Enhancements to both existing instructions and to the execution model were also proposed to improve performance. Chapter 4 proposed a microarchitecture for implementing the abstract machine and described its realization in hardware. Finally, Chapter 5 discussed the quantitative affects of the features of the PLM on performance. This Chapter summarizes the contributions of this research and provides direction for future work.
T. P. Dobry

Backmatter

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