Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!bellcore!faline!thumper!ulysses!andante!alice!ark
From: ark@alice.UUCP (Andrew Koenig)
Newsgroups: comp.lang.c
Subject: Re: Array indexing vs. pointers...
Message-ID: <8267@alice.UUCP>
Date: 6 Oct 88 01:07:52 GMT
References: <836@proxftl.UUCP> <3105@hubcap.UUCP> <1700@dataio.Data-IO.COM> <1703@dataio.Data-IO.COM>
Organization: AT&T Bell Laboratories, Liberty Corner NJ
Lines: 18

In article <1703@dataio.Data-IO.COM>, bright@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@europa.att.com