Data-Parallel Primitives for Spatial Operations Using PM Quadtrees*

Quadtrees* Erik G. Hoel Hanan Samet Computer Science Department Computer Science Department Center for Automation Research Center for Automation Research Institute for Advanced Computer Sciences Institute for Advanced Computer Sciences University of Maryland University of Maryland College Park, Maryland 20742 College Park, Maryland 20742 Abstract Data-parallel primitives for performing operations on the PM1 quadtree and the bucket PMR quadtree are presented using the scan model. Algorithms are described for building these two data structures that make use of these primitives. The data-parallel algorithms are assumed to be main memory resident. They were implemented on a Thinking Machines CM-5 with 32 processors containing 1GB of main memory.