John Darlington

A Transformation System for Developing Recursive Programs

A system of rules for transforming programs is described, with the programs in the form of recursion equations. An initially very simple, lucid, and hopefully correct program is transformed into a more efficient one by altering the recursion structure. Illustrative examples of program transformations are given, and a tentative implementation is described. Alternative structures for programs are shown, and a possible initial phase for an automatic or semiautomatic program-manipulation system is indicated.

A system which automatically improves programs

SummaryHere we give methods of mechanically converting programs that are easy to understand into more efficient ones, converting recursion equations using high level operations into lower level flowchart programs.The main transformations involved are (i) recursion removal (ii) eliminating common subexpressions and combining loops (iii) replacing procedure calls by their bodies (iv) introducing assignments which overwrite list cells no longer in use (compiletime garbage collection).

Some transformations for developing recursive programs

The paper describes a system of rules for transforming programs, the programs being in the form of recursion equations. The idea is to start with a very simple, lucid and hopefully correct program, then to transform it into a more efficient one by altering the recursion structure. Illustrative examples of program transformations are given, and a tentative implementation is described. We hope to throw some light on the alternative structures for programs, also to indicate a possible initial phase for an automatic or semi-automatic program manipulation system.

TemPSS: A Service Providing Software Parameter Templates and Profiles for Scientific HPC

Generating and managing input data for large-scale scientific computations has, for many classes of application, always been a challenging process. The emergence of new hardware platforms and increasingly complex scientific models compounds this problem as configuration data can change depending on the underlying hardware and properties of the computation. In this paper we present TemPSS (Templates and Profiles for Scientific Software), a web-based service for building and managing application input files using the concepts of software parameter templates and job profiles. Many complex, distributed applications require the expertise of more than one individual to allow an application to run efficiently on different types of hardware. TemPSS supports collaborative development of application configurations through the ability to save, edit and extend job profiles that define the inputs to an application. We describe the process of defining templates and profiles and the structures used to add an application template to the TemPSS service. We also detail the implementation of the service and describe its interfaces and functionality.