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From: djk@cs.columbia.edu (David Kurlander)
Newsgroups: comp.lang.clos
Subject: Object representation overhead
Message-ID: <1990Nov17.195029.27376@cs.columbia.edu>
Date: 17 Nov 90 19:50:29 GMT
Organization: Columbia University Department of Computer Science
Lines: 16

A quick experiment with Lucid 4.0's version of CLOS reveals that
simple-objects have an extra overhead of 20 bytes, while ordinary
structures have an overhead of 12.  What else tends to be stored in
objects aside from a pointer to a dispatch table?

(For that matter, why might structures have 12 bytes of overhead?  A 4
byte tag indicating structure + 4 byte tag indicating structure type
seems more than generous to me).

David


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David Kurlander				Department of Computer Science
djk@cs.columbia.edu			Columbia University