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Macro Algorithm for ISMOD Index Sequential Access Method Module Name Generation

IP.com Disclosure Number: IPCOM000075515D
Original Publication Date: 1971-Oct-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Radencic, GA: AUTHOR

Abstract

The improved algorithm is described with respect to ISMOD; however, it can be used in any input/output module (I/O MOD) with a comparative saving in macro code and assembly time.

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Macro Algorithm for ISMOD Index Sequential Access Method Module Name Generation

The improved algorithm is described with respect to ISMOD; however, it can be used in any input/output module (I/O MOD) with a comparative saving in macro code and assembly time.

All I/O MOD's generate unique names according to options specified by the caller of the macro. They also generate entry point names for any options which are subsettable. For instance, an ISMOD with TYPEFILE=RANSEQ can handle the work of an ISMOD which specifies either RANDOM, SEQNTL, or RANSEQ.

Therefore, entry points are generated for all three functions. The current macro codes set binary switches (SETB's) to indicate the presence of various optims. De-entry point names are then determined by testing all possible combinations of the switch settings and setting a character variable (SETC) for each possible result in each position of the module name.

The improved algorithm uses these SETB's to generate numeric values, each of which indicates a respective correct character for the SETC's from a string of all the possible values. This eliminates the need for the tedious testing of SETB's and individual setting of SETC's. The savings in macro code are in the order of a 25 per cent reduction from the original method. The saving in Source Statement Library space, Local Dictionary size, and Assembly time is considerable. The algorithm is relatively simple to implement and can be used to great advantage in other I/...