Ada 9X Project Report, The Fixed-Point Facility in Ada
Abstract
This report addresses a number of issues involving fixed-point arithmetic in Ada. A number of possible Ada 9X requirements are suggested for consideration. Ada includes a facility for declaration of and arithmetic on fixed-point values. The model is deliberately intended to be as close as possible to the Ada floating-point model, including the notion of model numbers and model intervals. The major difference is that the error is absolute, rather than relative; in other words, the model numbers are spaced evenly in the fixed- point case. This fixed-point facility is intended for a variety of uses: 1) Poor man's floating-point; 2) Increased accuracy; 3) Mapping data from specialized hardware and other external data; 4) A special, but important, case of external world fixed-point data arises in fiscal calculations, where quantities of money are typically decimal scaled fixed-point values (e.g., $56.34).
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1990
- Accession Number
- ADA221374
Entities
People
- John B. Goodenough
- Robert B. Dewar
Organizations
- Carnegie Mellon University