Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!haven!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.lang.c
Subject: Re: ambiguous ?
Message-ID: <11371@smoke.BRL.MIL>
Date: 21 Oct 89 22:47:40 GMT
References: <1989Oct20.175352.20598@utzoo.uucp> <14102@lanl.gov> <1989Oct21.072905.9039@utzoo.uucp>
Reply-To: gwyn@brl.arpa (Doug Gwyn)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 17

In article <1989Oct21.072905.9039@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes:
>Most Fortran programmers, of course, either don't bother at all [to prove
>their use of hardware floating-point is correct] ...
>Avoiding this nasty compromise requires doing all math symbolically, using
>complex and difficult exact representations, or at the very least using
>a very carefully-designed interval-arithmetic package.  How one does any
>of these things in Fortran is beyond me.

To be fair, while I agree that most Fortran programmers don't do this
properly, the main emphasis of Fortran is numerical programming, and
there has been a lot of work put into resolving these problems.  The
whole issue is a major branch of the field of numerical analysis.
Some popular Fortran libraries are carefully designed in this regard.

You're right about hardware floating point concerns making C's usual
areas of "ambiguity" (really not the right term for it) appear piddling
by comparison.