
220 Chapter 6 Implementation of floating-point arithmetic on a computer
6.10 Algorithms using the short accumulator
In the case ex ey r C 1 of the algorithm for the addition shown in Figure 6.18,
the mantissa my may be shifted to the right as many as r C1 digits. Thus the ensuing
addition, as described above, requires an accumulator of 2r C 1 digits after the point.
The multiplication algorithm commences with a correct calculation of the product of
the mantissas mx my . As with addition, this operation can be conveniently accommo-
dated within an accumulator of 2r C 1 digits after the point. However, we mentioned
at the beginning of this chapter ...