Path: utzoo!attcan!uunet!lll-winken!lll-lcc!ames!nrl-cmf!ukma!rutgers!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.std.c
Subject: Re: volatile registers
Message-ID: <9271@smoke.BRL.MIL>
Date: 4 Jan 89 07:21:48 GMT
References: <141@bms-at.UUCP> <275@twwells.uucp> <15166@mimsy.UUCP> <9236@smoke.BRL.MIL> <15171@mimsy.UUCP> <9316@ihlpb.ATT.COM>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 8

In article <9316@ihlpb.ATT.COM> nevin1@ihlpb.UUCP (55528-Liber,N.J.) asks:
>Is it even possible to have a strictly conforming C program whose
>behavior would change by declaring any of its variables volatile?

Declaring a truly non-volatile object as "volatile" would not affect
the virtual-machine semantics, but it would in general have an effect
on code generation (and thus reduce execution speed, etc.).  That's
why it's not the default.