Rationale for the Proposed Standard for a Generic Package of Primitive Functions for Ada

Abstract

This paper supplements the "Proposed Standard for a Generic Package of Primitive Functions for Ada," written by the ISO-IEC/JTC1/SC22/WG9 (Ada) Numerics Rapporteur Group. Based on recommendations made jointly by the ACM SIGAda Numerics Working Group and the Ada-Europe Numerics Working Group, the proposed primitive functions standard is the second of several anticipated secondary standards to address the interrelated issues of portability, efficiency, and robustness of numerical software written in Ada. Its purpose, features, and developmental history are outlined in this commentary.

Scientific Computing in the CH Programming Language

“…Even for IEEE machines, if there is no provision for propagating the sign of zeros, infinity, and NaN in a consistent and useful manner through the software support, they will have to be programmed as if zeros are unsigned without infinity and NaN. For example, the proposed Ada standard does not distinguish -0.0 from 0.0 and has no provision for consistent handling of infinity and NaN [13][14][15][16][17][18]. As another example, the standard mathematical C library implemented by Plauger [10] has provisions for signed infinities and NaN, but zeros are unsigned.…”