Optimising code generation with haggies

This article describes haggies, a program for the generation of optimised programs for the efficient numerical evaluation of mathematical expressions. It uses a multivariate Horner-scheme and Common Subexpression Elimination to reduce the overall number of operations.The package can serve as a back-end for virtually any general purpose computer algebra program. Built-in type inference that allows to deal with non-standard data types in strongly typed languages and a very flexible, pattern-based output specification ensure that haggies can produce code for a large variety of programming languages.We currently use haggies as part of an automated package for the calculation of one-loop scattering amplitudes in quantum field theories. The examples in this articles, however, demonstrate that its use is not restricted to the field of high energy physics.

Program summary

Program title: haggiesCatalogue identifier: AEGF_v1_0Program summary: URL: http://cpc.cs.qub.ac.uk/summaries/AEGF_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU GPL v3No. of lines in distributed program, including test data, etc.: 56 220No. of bytes in distributed program, including test data, etc.: 579 010Distribution format: tar.gzProgramming language: Java, JavaCCComputer: Any system that runs the Java Virtual MachineOperating system: Any system that runs the Java Virtual MachineRAM: Determined by the size of the problemClassification: 4.14, 5, 6.2, 6.5, 11.1Nature of problem: Generation of optimised programs for the evaluation of possibly large algebraic expressionsSolution method: Java implementationRunning time: Determined by the size of the problem