Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!bu-cs!purdue!umd5!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: no noalias not negligible (long)
Message-ID: <7950@brl-smoke.ARPA>
Date: 21 May 88 15:01:27 GMT
References: <54080@sun.uucp> <11608@mimsy.UUCP>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 14

In article <11608@mimsy.UUCP> chris@mimsy.UUCP (Chris Torek) writes:
>Provide `#pragma's.  Some people claim that a pragma is not allowed to
>declare such semantics as volatility or lack of aliasing; I disagree.

Although you can find X3J11 committee members on both sides of this
debate, apparently all the editors of official documents are in
agreement that the proposed Standard does not permit (and certainly
is not intended to permit) #pragma to allow violation of any portion
of the rest of the Standard specifications.  Since the rest of the
proposed Standard requires honoring of aliasing, #pragma cannot be
used to change this.

I used to think otherwise but have been convinced of this.  I agree
that it is not obvious.