An important strategy to enhance both the reliability and performance of high-level program execution is to have computer architecture provided with the mechanisms, such as i) to address information in a unified manner regardless of the structure and/or of the size of information objects, and ii) to dynamically check the eligibility of information accesses. This paper firstly gives the foundation for such abstraction mechanisms through examining the semantic structure of information objects. Information is hereby formalized as a set of relations between an access and the entity that is accessed. The relations are hierarchically classified into four categories, each of which associates to the corresponding level of abstraction. Object-oriented architecture which reflects this hierarchical classification directly in its storage organization is then proposed. This architecture is called the abstract storage architecture. Issues in designing the abstract storage architecture are described. The effectiveness of such architecture is concluded from the view points of both the implementation of existing high-level languages and the design of future high-level languages.

This paper describes a microprogram optimization technique called MORIF. The technique is general enough to treat machines whose microoperations require multiple machine cycles on a subcycle basis. The technique is applicable to microinstruction formats varying from horizontal to partially encoded, and to vertical. The technique includes global optimization algorithms for microprograms containing loops and recursive subroutines. Evaluation of the technique is performed from both the viewpoints of the complexity of the devised algorithms, and efficiency of generated object microcodes.