Abstract

This paper describes the transformation of (almost arbitrary) sequential functions on covers to parallel, collective operations (skeletons). This allows the direct re-use of existing, but sequential, code on parallel machines without the necessity to handcode the desired parallel operations. A necessary pre-requisite for this skeleton lifting is the availability of a cover which holds the mapping information of the local subobjects, including their topology information. The lifting transformation distinguishes sequential values, which are available on each processor, from parallel values, which are only stored once. Accesses to parallel values are either ignored locally if they will be computed on another processor, or they induce communication messages to transfer the necessary data, depending on the behavior of the original function.

Citations