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From: jer@peora.UUCP (J. Eric Roskos)
Newsgroups: net.arch
Subject: Re: Re: Where to do stack checking, etc.
Message-ID: <1656@peora.UUCP>
Date: Thu, 19-Sep-85 08:03:46 EDT
Article-I.D.: peora.1656
Posted: Thu Sep 19 08:03:46 1985
Date-Received: Fri, 20-Sep-85 06:06:59 EDT
References: <796@kuling.UUCP> <1713@orca.UUCP> <1599@peora.UUCP> <335@ihlpl.UUCP> <2384@uvacs.UUCP>
Organization: Perkin-Elmer SDC, Orlando, Fl.
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> I'm still looking for a machine that will trap references to uninitialized
> data.

This is a hard problem.  My dissertation advisor (R. I. Winner) did a good
bit of research on this problem; see, for example, Winner, R. I.,
"Unassigned Objects," ACM TOPLAS, October, 1984.  The problem is that either
you have to have a unique bit pattern representing unassigned data (which
means there's one value that has a special meaning), or you have to have a
tag bit denoting "unassigned".

Various interesting models of memory are possible if you generalize the
unassigned object.
-- 
Shyy-Anzr:  J. Eric Roskos
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