POFAC(ID:652/pof001)

A subset of Fortran as a virtual machine

Ecole Royale Militaire, Brussels, Belgium
Related languages
FORTRAN IV => POFAC   Extension of
References:
  • "POFAC Description", R. Haentjens, Report 19, Cenre d'Information, Ecole Royale Militaire, Brussels, 1973. view details
  • Gennart, P. E.; Haentjens, R.; Horne, R.; Lathuy, L.; Mathieu, J. "Portability of an ALGOL 68 compiler" view details
          in Machine Oriented Higher Level Languages (van der Poel, Maarsen, editors) North Holland 1974 view details
  • Brown, P. J. review of Gennart et al 1974 view details Abstract: This paper describes an abstract machine, called POFAC, for encoding the syntax analysis phase for an ALGot 68 compiler. POFAC is a subset of FORTRAN that is suitable for mapping by STAGE2. A program in POFAC contains a lot of ~ extra information, which, though not recognized by a' FORTRAN compiler, helps STAGE2 generate efficient code. For example, some lines that are written as FORTRAN comments are actually interpreted as instructions by STAGE2. Furthermore, certain variable names correspond to fixed registers on a STAGE2 mapping, and programs make great use of this to gain efficiency. l

    The advantages of POFAC being a subset of FORTRAN is that the FORTRAN compiler can be used during the debugging stages of a POFAC program. When the program is correct, STAGE2, which runs much slower but generates better code, can be used to perform the compilation. The paper contains some interesting figures on the relative sizes of object programs produced by various means. ~

          in ACM Computing Reviews 16(03) March 1975 view details