We survey parallel programming models and languages using 6 criteria [:] should be easy to program, have a software development methodology, be architecture-independent, be easy to understand, guranatee performance, and provide info about the cost of programs. ... We consider programming models in 6 categories, depending on the level of abstraction they provide.

Parallel skeletons intend to encourage programmers to build...

Parallel primitives (skeletons) intend to encourage programmers to build a parallel program from ready-made components for which efficient implementations are known to exist, making the parallelization process easier. However, programmers often suffer from the difficulty to choose a combination of proper parallel primitives so as to construct efficient parallel programs. To overcome this difficulty, we shall propose a new transformation, called diffusion, which can efficiently decompose a recursive definition into several functions such that each function can be described by some parallel primitive. This allows programmers to describe algorithms in a more natural recursive form. We demonstrate our idea with several interesting examples. Our diffusion transformation should be significant not only in development of new parallel algorithms, but also in construction of parallelizing compilers.

Solid modelling using constructive solid geometry (CSG) includes many examples of stylised divide-and-conquer algorithms. We identify the sources of these recurrent patterns and implement a Geometric Evaluation Library (GEL) which captures them as higher order functions. This library then become the basis of developing CSG applications quickly and concisely. GEL is currently implemented as a set of separately compiled modules in the pure functional language Hope+. We evaluate our work in terms of performance and general applicability. We also assess the benefits of the functional paradigm in this domain and the merits of programming with a set of higher order functions. 1 Introduction We present a case study in functional programming in the field of solid modelling using Constructive Solid Geometry (CSG). It is motivated by the observation that this application domain uses many (potentially parallel) stylised algorithms based on the divide-and-conquer (D&C) paradigm. Previous...

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Data parallelism is currently one of the most successful models for programming massively parallel computers. The central idea is to evaluate a uniform collection of data in parallel by simultaneously manipulating each data element in the collection. Despite many of its promising features, the current approach suffers from two problems. First, the main parallel data structures that most data parallel languages currently support are restricted to simple collection data types like lists, arrays or similar structures. But other useful data structures like trees have not been well addressed. Second, parallel programming relies on a set of parallel primitives that capture parallel skeletons of interest. However, these primitives are not well structured, and efficient parallel programming with these primitives is difficult. In this paper, we propose a polytypic framework for developing efficient parallel programs on most data structures. We showhow a set of polytypic parallel primitives can be formally defined for manipulating most data structures, how these primitives can be successfully structured into a uniform recursive definition, and how an efficient combination of primitives can be derived from a naive specification program. Our framework should be significant not only in development of new parallel algorithms, but also in construction of parallelizing compilers.

One problem of parallel computing is that parallel computers vary greatly in architecture so that a program written to run efficiently on a particular architecture, when porting to a different architecture, would often need to be changed and adapted substantially in order to run with reasonable performance on the target architecture. Porting with performance is, hence, labour-intensive and costly. A method of parallel programming using the Bird-Meertens Formalism where programs are formulated as compositions of (mainly) higher order functions on some data type in the data parallel functional style has been proposed as a solution. The library of (mainly) higher-order functions in which all communication and parallelism in a program is embedded could (it is argued) be implemented efficiently on different parallel architectures. This gives the advantage of portability between different architectures with reasonable and predictable performance without change in program source. ...