Floating-Point Formats and Environment

Abstract

Our main focus in this chapter is the IEEE¹ 754-1985 Standard for Floating-Point Arithmetic [10], and its recent revision [187]. A paper written in 1981 by Kahan, Why Do We Need a Floating-Point Standard? [202], depicts the rather messy situation of floating-point arithmetic before the 1980s. Anybody who estimates that the current standards are too constraining and that circuit and system manufacturers could build much more efficient machines without them should read that paper and think about it. Even if there were at that time a few reasonably good environments, the various systems available then were so different that writing portable yet reasonably efficient numerical software was extremely difficult.