Efficient management of complex elements in physical IC design

An efficient data structure for the management of complex elements in physical design is described. The data structure is based on the use of low-level algorithms for the management of simple elements, such as rectangles and trapezoids. These algorithms constitute a generalization of those used for the management of the basic corner stitching data structure; the main enhancement is constituted by the possibility of managing simple elements with 45° sides. At a higher level, a hierarchical structure is implemented which is able to manage more complex elements such as generic nonrectilinear polygons. This is performed by providing the user with a complete set of procedures for the creation and management of polygons. The algorithm is based on the decomposition of a polygon into a disjoint set of simple elements, managed through the use of the available low-level procedures