This paper shows how thorough object code optimization has simplified a compiler and made it easy to retarget. The code generator forgoes case analysis and emits naive code that is improved by a retargetable object code optimizer. With this technique, cross-compilers have been built for seven machines, some in as few as three person days. These cross-compilers emit code comparable to host-specific compilers. Categories and Subject Descriptors: D.3.4 [Programming Languages]: Processors--code genera-tion; compilers; optimization

This article describes the key principles behind the design and implementation of a global code improver that has been use to construct several high-quality compilers and other program transformation and analysis tools. The code improver, called vpo, employs a paradigm of compilation that has proven to be flexible and adaptable---all code improving transformations are performed on a target-specific representation of the program. The aggressive use of this paradigm yields a code improver with several valuable properties. Four properties stand out. First, vpo is language and compiler independent. That is, it has been used to implement compilers for several different computer languages. For the C programming language, it has been used with several front ends each of which generates a different intermediate language. Second, because all code improvements are applied to a single low-level intermediate representation, phase ordering programs are minimized. Third, vpo is easily retargeted and handles a wide variety of architectures. In particular, vpo's structure allows new architectures and new implementations of existing architectures to be accommodated quickly and easily. Fourth and finally, because of its flexible structure, vpo has several other interesting uses in addition to its primary use in an optimizing compiler. This article describes the principles that have driven the design of vpo and the implications of these principles on vpo's implementation. The article concludes with a brief description of vpo's use as a back end with front ends for several different languages, and its use as a key component

This report describes the design and implementation of HASKELL system. The areas implemented are the lexical analysis, parsing, intepretation of the lambda tree, and machine code generation. Because of the size, complexity and novelty of the language many of these areas present particular difficulty. A considarable amount of meta-programming was used in order to tackle the size of the project. Contents Introduction v 1 Lexical Analysis 1 1.1 Technical Overview 1 1.2 General Description 3 1.3 The Layout Rule 4 1.4 Alternative Design 5 1.5 Coding for Speed 6 1.5.1 Token Recognition 7 1.5.2 Character Copying 8 1.5.3 Memory Allocation 9 1.5.4 Symbol Table Updates 9 1.5.5 The Ultimate Combination 9 1.5.6 Performance 10 1.6 Testing 10 2 Parsing 11 2.1 Technical Overview 11 2.2 General Description 12 2.3 Handling the Grammar Ambiguities 13 2.3.1 Definable Operators and Function Applications 13 2.3.2 General 15 2.3.3 September Version 15 2.3.4 April Grammar changes 17 2.3.5 April Version 18 ...

This working paper series is intended to facilitate discussion and encourage the exchange of ideas. Inclusion here does not preclude publication elsewhere. It is the original work of the author(s) and subject to copyright regulations. encouraging creative research

lcc is a new retargetable compiler for ANSI C. Versions for the VAX, Motorola 68020, SPARC, and MIPS are in production use at Princeton University and at AT&T Bell Laboratories. With a few exceptions, little about lcc is unusual --- it integrates several well engineered, existing techniques --- but it is smaller and faster than most other C compilers, and it generates code of comparable quality. lcc's target-independent front end performs a few simple, but e#ective, optimizations that contribute to good code; examples include simulating register declarations and partitioning switch statement cases into dense tables. It also implements target-independent function tracing and expression-level profiling. Introduction Reprinted from SIGPLAN Notices 26, 10 (Oct. 1991), 29--43. Copyright 1991, Association for Computing Machinery, Inc., reprinted by permission. lcc is a new retargetable compiler for ANSI C [2]. It has been ported to the VAX, Motorola 68020, SPARC, and MIPS R3000, a...

Over the recent past, stylized facts have not yielded a synthesis regarding the predictability of returns for alternative investment assets such as hedge funds. Recent studies on alternative asset return predictability have added to the ambiguity. These studies suggest that classification prediction methods may dominate more traditional return-level prediction methodology. This paper examines the predictive accuracy of three alternate radial basis function neural networks when applied to the returns of thirteen Credit Swiss First Boston/Tremont (CSFB) hedge fund indices. We provide evidence that the Kajiji-4 RBF neural network dominates within the RBF topology in the prediction of hedge fund returns by both level and classification. The results also show that the Kajiji-4 method is capable of near perfect directional prediction.