FITZWATER Autocoder(ID:7957/)

Autocoder with Fortran loops and subscripts 

Extension of Autocoder by Fitzwater of Iowa State Uni to permit Fortran style subscripts and Do-style loops to Autocoder.

References:
  • Fitzwater, D. R. "A storage allocation and reference structure" pp542-545 view details Abstract: A method is proposed and discussed which allows a subscripted-variable capability (in the FORTRAN sense) to be added to AUTOCODER-Type assembly systems. External link: Online copy Extract: Introduction
    Introduction
    One of the common disadvantages of a machine-oriented language is the general lack of a convenient structure for referencing subscripted variables such as are provided by DO loops and subscripts in FORTRAN. The powerful structure of an AUTOCODER language, which permits addition of new macro generators, should be capable of containing convenient subscript and looping macro statements. Indeed, because of the generally greater flexibility of an AUTOCODER language, one would suspect that even more powerful facilities might be attempted. A very powerful and reasonably simple macro structure to provide such facilities has been developed, and is described here. Although the specific details are designed for application to the IBM 7070/72/74 series, the principles involved may be applicable in other computers.
    To obtain the flexibility which is required to exploit the AUTOCODER language, the storage allocation, or that portion to be referenced by this technique, is described by a list which is essentially in a standard outline form. All information as to storage allocation is contained in this list.
    The program may then be written without concern for the actual sizes or arrays, variable data fields, and so forth. A new macro statement, INDEX, contains information defining the symbols to be used in the program and also provides subscript range information. The purpose of INDEX is to make an appropriate set of index registers available to the programmer according to his subscript specifications in INDEX.
    The second new macro statement, LOOP, contains information about the nested loop level and also specifies the subscripted variables to be incremented in the loop process at that subscript level. Since the standard assumption is that all of the permissible subscript range will be processed by repeated looping, if a subrange is desired the appropriate range information must be supplied by the appropriate subscript entry in the corresponding INDEX statement.
    The two macro generators INDEX and LOOP have been programmed, debugged, and submitted to the GUIDE library. Only a brief and abbreviated description of the structure and capabilities of this technique is given here.
          in [ACM] CACM 7(09) September 1964 view details