Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!cookie.dec.com!devine
From: devine@cookie.dec.com (Bob Devine)
Newsgroups: comp.lang.c
Subject: Re: `noalias' vs `register'
Message-ID: <8712170057.AA17035@decwrl.dec.com>
Date: 17 Dec 87 00:57:04 GMT
Organization: Digital Equipment Corporation
Lines: 21

In article <6833@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) ) writes:
>
>The "noalias" type qualifier promises that the object can only be
>modified by a single handle (as I said), thereby permitting the
>optimizer to do things that are not safe otherwise [...]

  I dislike this creation.  I can see that some time/space savings
is possible *if it is used correctly* but I doubt it.  I simply don't
see it as worth the bother.  Most folks would drop into assembly or
otherwise recode if they are that concerned with optimization.  I 
see problems with someone later recoding parts of a program and 
gets bitten by 'noalias' -- there are too many programmer (bad) habits.

  A better way, in hindsight, would have been to have a 'alias' keyword
that designates those cases where multiple handles are used; all other
cases could then be assumed to be optimizable.  Too late.

  Finally, if the committee wants to provide the negative-name for
attributes perhaps they should use 'noregister' instead of 'volatile'.

Bob Devine  ...!decwrl!cookie.dec.com!devine