Path: utzoo!attcan!uunet!husc6!bloom-beacon!gatech!uflorida!haven!ncifcrf!nlm-mcs!adm!smoke!gwyn
From: gwyn@smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: Rearranging FP expressions
Message-ID: <8591@smoke.ARPA>
Date: 3 Oct 88 03:25:23 GMT
References: <4700017@m.cs.uiuc.edu>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 10

In article <4700017@m.cs.uiuc.edu> wsmith@m.cs.uiuc.edu writes:
>The problem:  How can C know when it is safe to rearrange expressions,
>		especially floating point expressions.

You seem to be assuming that it is obvious what constitutes a
"rearranged" expression.  That is not at all obvious.  The
current proposed C standard spells out what arithmetic order
constraints must be obeyed by a conforming implementation, and
it does appear to have adequately addressed this aspect of
numerical programming needs.