Type determination in an optimizing compiler for APL

This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or "target " for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or dupUcate copy. Unless we meant to delete copyrighted materials that should not have been filmed, you will find

Idiom matching: an optimization technique for an APL compiler

This thesis describes the design of an idiom matching technique in a compiler for APL. Idioms are programming language constructs used by programmers for the logical primitive operations for which no language primitives exist. Due to APL\u27s richness of operators, idioms tend to appear at the expression level. APL users have to pay a very high price to execute their APL programs with operator-by-operator execution in conventional translators. However, each idiom can be treated as a unit. It has been shown (2) that the saving from optimizing such idioms can be very impressive. Other researchers (1,3) have collected lists of idioms for APL;Idiom matching consists of two problems, recognition and selection, which are dealt with in this work. The idiom recognition problem is solved by a finite tree automaton. This approach constructs an automaton directly from a regular tree expression for a set of idioms. A practical automaton minimization algorithm is developed that obtains a time bound of O(n(\u272)(.)log n) for any binary tree automaton with n states. The selection problem, locating the best non-overlapping idioms in an expression tree, is solved in O(n) time;1. Brown, W. E. Toward an Optimizing Compiler for a Very HighLevel Language. Ph.D. dissertation, Iowa State University, 1979;2. Miller, T. C. Tentative Compilation: A Design for an APLCompiler. Ph.D. dissertation, Yale University, 1978;3. Perlis, A. J. and Rugaber, S. The APL Idiom List. ResearchReport #87, Department of Computer Science, Yale University,April, 1977