Path: utzoo!mnetor!uunet!husc6!cmcl2!brl-adm!umd5!purdue!i.cc.purdue.edu!j.cc.purdue.edu!pur-ee!uiucdcs!uxc.cso.uiuc.edu!ccvaxa!aglew
From: aglew@ccvaxa.UUCP
Newsgroups: comp.arch
Subject: Re: self-modifying code
Message-ID: <28200104@ccvaxa>
Date: 19 Feb 88 17:32:00 GMT
References: <486@taux01.UUCP>
Lines: 22
Nf-ID: #R:taux01.UUCP:486:ccvaxa:28200104:000:977
Nf-From: ccvaxa.UUCP!aglew    Feb 19 11:32:00 1988


Branch target caching in SOAR, and some 68000 SMALLTALK implementations,
is self modifying.

Smalltalk methods are multiway branches based on possibly complicated
conditions. Instead of evaluating all the conditions, these implementations
branch to the most recently used method, and do a simple validity check,
defaulting to the more general case. The general case patches a branch
back into the code.

Of course, there are other ways to do it...


Andy "Krazy" Glew. Gould CSD-Urbana.    1101 E. University, Urbana, IL 61801   
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