Path: utzoo!mnetor!uunet!husc6!hao!oddjob!gargoyle!ihnp4!ttrdc!levy
From: levy@ttrdc.UUCP (Daniel R. Levy)
Newsgroups: comp.lang.c
Subject: Re: noalias, ordinary, volatile
Message-ID: <2047@ttrdc.UUCP>
Date: 20 Dec 87 01:59:22 GMT
References: <8712170057.AA17035@decwrl.dec.com> <6006@j.cc.purdue.edu>
Distribution: na
Organization: AT&T, Skokie, IL
Lines: 37

In article <6006@j.cc.purdue.edu>, ksb@j.cc.purdue.edu (Kevin Braunsdorf) writes:
> I have been working on an optimizer that would take advantage of the
> "noalias" concept (here we call it "exclusive" access, rather than
> "noalias" data)....

> 	i = 1;
> 	while (i)
> 		/*empty*/;

> [if i is declared as]
> exclusive:
> 	We scream and die, i cannot change in the loop (if you
> 	want to loop forever you have to use
> 		spin();
> 	for our flow analysis to pass your code.).

UGH.  I can see putting out a WARNING about the infinite loop, and it is poor
practice to just busy-wait (for something like a signal) but why DISALLOW
it unless the code uses your non-portable spin() call?

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-- 
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