Systems Programming Language 

for Systems Programming Language.

D.B. Wortman, U Toronto. Philips Data Sys, Netherlands, 1971.

PL/I subset/extension for the P1000. Symbolic constants, pointer arithmetic, inline assembly code. Used to implement compilers, operating systems, and database.

Related languages
PL/I => SPL   Subset
SPL => Micro SPL   Subset
SPL => Student PL/I   Subset

  • Klunder, J."Experiences With SPL" pp385-393 view details
          in Machine Oriented Higher Level Languages (van der Poel, Maarsen, editors) North Holland 1974 view details
  • Frailey, D. J. Review of Klunder 1973 view details Abstract: SPL is a PL/I-based systems programming language for the Philips P1000 computer family. Though the language is incnded to be high level and machine independent, it incorpoates a few "windows" to allow access to machine functions. the net result is a PL/I subset, extended to allow (or make more convenient) a number of features essential to general sys symbolic constants (as in the SET or EQU pseudo-ops commonly found in assemblers), and global variables.

    The paper gives data from a variety of applications showing that the "expansion factor" (ratio of SPL to assembly language for the number of instructions generated or executed) ranges from .96 to 1.86. The greatest expansions tend to come from use of the highest level features of the language. Other data relate to programmer productivity and analysis of errors (although little comparison is made with assembly language in these areas). As might be expected, the greatest source of errors involves interfaces with external programs.

    In summary, the paper provides a set of interesting and believable data about the use of a high level systems programming language, as well as a good discussion of why PL/I is deficient for general systems programming work.

          in ACM Computing Reviews 16(02) February 1975 view details