A Parser-Generating System for Constructing Compressed Compilers This paper describes a parser-generating system (PGS) currently in use on the CDC-6500 computer at Purdue University. The PGS is a Fortran-coded compiler. In the input translation grammar, each BNF syntactic rule corresponds to a (possibly empty) "code generator" realizable as an assembly language, Fortran or Algol, subroutine that is called whenever that syntactic rule is applied in the parse of a program. Typical one-pass compilers constructed by the PGS translate source programs at speeds approaching 14,000 cards per minute. For an XPL compiler, the parser program and its tables currently occupy 288 words of 60-bit core memory of which 140 words are parsing table entries and 82 words are links to code generators. CACM November, 1973 Mickunas, M. D. Schneider, V. B. parser generators, translator writing systems, syntactic analysis, normal-form grammars, pushdown automata, translation grammars, translator optimization, compression algorithm 4.12 5.22 5.23 CA731103 JB January 20, 197810:41 AM 2179 4 2423 2423 4 2423 2423 4 2423 1337 5 2423 2015 5 2423 2423 5 2423 2423 5 2423 2423 5 2423 2733 5 2423 1781 6 2423 2179 6 2423 2423 6 2423 2786 6 2423 799 6 2423