
206 Chapter 6 Implementation of floating-point arithmetic on a computer
self-explanatory. The operands are always called x and y. The result is called z.Inthe
following algorithms, all operator symbols C, , , =, , , <, > are defined and used
in the sense of integer arithmetic. A left (resp. right) shift is expressed by a multiplica-
tion (resp. division) by powers of the base b. As a (rather awkward) device to describe
certain digit manipulations, we occasionally employ the function Œx :D entire.x/.It
determines the greatest integer less than or equal to x.
6.3 Addition and subtraction
We assume that the long accumulator is being used. We denote ...