Interval Maintenance of Dynamically Changing Flow Graphs

Many compilers incorporate an optimization phase during the development of the final object code. Most optimization phases utilize a flow graph and partition it into disjoint single entry regions to perform various global flow analyses. The interval is a commonly used single entry region and interval analyses have been developed for performing standard analyses such as live variable analysis, etc. This paper presents a technique for maintaining the interval structure as the underlying flow graph is dynamically modified. The techniques presented preserve the interval order required by many interval analyses and do not require that the underlying flow graph be reducible

Number of Binary Trees

A data encoding scheme involving binary tree encodements is presented and analyzed. A closed-form formula for the number of n-bit legal memory configurations is developed. It is shown that the storage capacity loss due the use of this scheme is not significant for large n

Communicative Processes: A Model of Communication

This paper introduces a conceptual model of communicative organization as a part of the formal semantic study of distributed computation. The model includes, as communication primitives, three independent modes of communication: mailing, posting, and broadcasting. Mailing models thin-wire communication, and posting models shared memory communication. While broadcasting is not prominent in today\u27s parallel programming languages, it has an important role to play in distributed computation. Other fundamental notions in the model are process, symbol, site, process class, symbol class and site class

The Syntax and Parsing of the Two-Dimensional Languages

This report introduces the idea of expressing programming concepts in a two-dimensional (pictorial) language. A specific two-dimensional language, Show and Tell, is briefly presented and formalisms that might be used to define the syntax of such a language are discussed. An abstraction of Show and Tell is defined, and a specific grammar formalism is presented for defining the syntax of this abstraction. The mechanisms found in expert systems are shown to be sufficient to parse languages defined by this formalism

Information Theoretic Estimation of Clone Overlap Probabilities

This technical report describes preliminary research investigating the relationship between information theory and Bayes\u27 theory for estimation of the probability of clone overlap for the use in DNA restriction mapping. A number of languages (along with information theoretic metrics) capable of describing a hypothesized overlap are presented. For each language, the MML criterion is applied to the encoded overlaps of a pair of clones to search for that overlap which is most probable. The objective is to order the pair\u27s encoded overlaps, based on the MML criterion, from the most to the least probable. This ordering is compared to the ordering suggestion by the Bayesian probabilistic approach