Abstract
Compilers for some programming languages are traditionally considered to be best implemented with a front end 1991 that makes only one pass over the source program. A FORTRAN compiler was converted from such a design to one that uses two passes for the benefit of obtaining a front end that is easier to understand and maintain. The details of which language features motivated this conversion are presented. Performance results are also presented that show there was only a 4% increase in compile time after the conversion. © 1991, ACM. All rights reserved.