Array indexing vs. pointers...
Andrew Koenig
ark at alice.UUCP
Thu Oct 6 11:07:52 AEST 1988
In article <1703 at dataio.Data-IO.COM>, bright at Data-IO.COM (Walter Bright) writes:
> The result may differ in the last bit of the significand because
> of this. However, in most cases, that is irrelevant and the
> multiply will be significantly faster.
If, however, you want your compiler to implement IEEE floating point,
you had better not substitute a multiply by 0.1 for a divide by 10.
IEEE defines the results of addition, subtraction, multiplication,
division, square root, and a few other operations precisely -- down
to the last bit. Either you get the right answer or you don't.
It is true that in many cases users don't need the last bit or so,
but a language implementer has an obligation to give it to the
people who demand it.
--
--Andrew Koenig
ark at europa.att.com
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