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From: flee@shire.cs.psu.edu (Felix Lee)
Newsgroups: comp.std.c
Subject: Re: Volatile (was Re: observability)
Message-ID: <FLEE.89Sep14225129@shire.cs.psu.edu>
Date: 15 Sep 89 02:51:29 GMT
References: <28993@news.Think.COM> <7330001@hpfcso.HP.COM>
Sender: news@psuvax1.cs.psu.edu
Organization: Penn State University Computer Science
Lines: 11
In-reply-to: mike@hpfcso.HP.COM's message of 13 Sep 89 15:41:08 GMT

In <7330001@hpfcso.HP.COM>,
   Mike McNelly <mike@hpfcso.HP.COM> writes:
> Ah, but any compiler that has optimization capabilities that would allow
> it to nullify a useless program invariably does not do such optimization
> unless you ask for it with flags such as -O.

Bad assumption.  The High C compiler (on IBM RTs) always does at least
trivial optimization.  Warnings like "Expression has no side effects"
and "Variable is never referenced" mean relevant code has disappeared.
--
Felix Lee	flee@shire.cs.psu.edu	*!psuvax1!flee