Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!ucsd!ames!haven!ncifcrf!nlm-mcs!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn)
Newsgroups: comp.std.c
Subject: Re: Questions about NCEG
Message-ID: <13046@smoke.BRL.MIL>
Date: 4 Jun 90 16:33:25 GMT
References: <15576@bfmny0.BFM.COM> <1017@s6.Morgan.COM> <1762@tkou02.enet.dec.com>
Organization: U.S. Army Ballistic Research Laboratory, APG, MD.
Lines: 19

In article <1762@tkou02.enet.dec.com> diamond@tkou02.enet.dec.com (diamond@tkovoa) writes:
>Unfortunately, C errs in the opposite direction.  It would have been
>better to say nothing about precision (as is done for arithmetic and
>fprintf) than to encourage excessive carelessness.  The existing wording
>really ought to be changed one way or another by the interpretation
>committee.

To the contrary, apart from the fact that X3J11 during the interpretations
phase is not in a position to change wording in the standard, the existing
wording on this was carefully hammered out in consultation with numerical
programming specialists, and includes sufficient latitude to guarantee
reasonable implementation on a variety of real architectures.

I don't think the wording "encourages excessive carelessness", because to
assure conformance with the specification the implementor has to do pretty
much the same work as he would were the specification even tighter (which
it couldn't be without causing problems for many existing architectures).
After taking that much trouble to ensure adequate precision, why would one
expect the implementor to then deliberately provide suboptimal precision?