PSE4 Abstract

Title: Intermediate Language/Compiler (PSE4)

Authors: T.S. Papatheodorou

Email: ptheodor@cti.gr

Date: July 1994

Abstract:

In the framework of Problem Solving Environments and for PDE-based problems, a very high level language is proposed, the compiler of which generates code in a given `common', underlying parallel programming language. The proposed language is viewed as an extension of the underlying language. It is designed to be used for very high level operations, interfacing with foreign numerical solvers, programming from scratch and programming for parallel numerical computing (with emphasis on the domain decomposition paradigm). We identify an initial but sufficient set of language features to support these requirements. We justify these features and we demonstrate the feasibility of their implementation through the generation of FORTRAN-like code. Specific and well justified features introduced here include those for the complicated case of domain definition and processing, index sets and arrays, functions, capturing the vast variety of mathematical forms that appear in PDE-based models, iterating with parametrized sets of problems, stencils for programming from scratch and interfacing with existing solvers. Several `types' are proposed that can be actually implemented as such for the development of an intermediate efficient language. These include the domain, function, equation, problem and stencil types. No attention is paid, at this stage, on the exact syntax of the various types involved which are implemented here (for demonstration purposes) as arrays, functions or subroutines in a FORTRAN-like language. Our approach is also based on the development of both (1) an open list of built-in standard libraries, similar to library functions in FORTRAN and (2) a powerful set of operations with the library utilities. Examples for (1) and (2) are presented here and their powerful use is demonstrated with representative applications, including a problem pertaining to the torsion of a bimetal shaft and including the domain decomposition paradigm.

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