Article View: rec.games.corewar
Article #228Re: SLT
From: Jeff Raven
Date: Thu, 12 Nov 1992 23:31
Date: Thu, 12 Nov 1992 23:31
33 lines
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1540 bytes
>Well that isn't exactly what my problem is... Take the following code for
>instance :
> JMP lbl, #-1
> DAT #0, #0
> SLT -1, -2
>Now, the SLT compares #0 to #-1, but is #0 less than or greater than #-1
>???
>Is #-1 converted to CORESIZE-1 ??? Or does the comparison evaluate as true
>(i.e. #-1 is less than #0) ?
In corewars, there is no such thing as a negative value - all arithmetic
is done modulo CORESIZE. When the above commands are assembled, the lines
will become (assuming CORESIZE = 8000) :
JMP lbl, #7999
DAT #0, #0
SLT 7999, 7998
Therefore, the comparison will be between 0 and 7999. Then the SLT
will evaluate as true since 0 < 7999. The modulo arithmetic applies
to every command - so
one DAT #2
two DAT #1
SUB one, two
will change things to
one DAT #2
two DAT #7999
SUB one, two
Answer your question?
Jeff Raven
jar129@psuvm.psu.edu
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Path: arc1-ca.pugleaf.net!sparky!uunet!gossip.pyramid.com!decwrl!netsys!agate!usenet.ins.cwru.edu!magnus.acs.ohio-state.edu!zaphod.mps.ohio-state.edu!rpi!usc!sol.ctr.columbia.edu!eff!news.byu.edu!yvax.byu.edu!cunyvm!psuvm!jar129 Newsgroups: rec.games.corewar Subject: Re: SLT Message-ID: <92317.183133JAR129@psuvm.psu.edu> From: Jeff Raven <JAR129@psuvm.psu.edu> Date: Thu, 12 Nov 1992 18:31:33 EST References: <1992Nov8.195147.29858@cs.kuleuven.ac.be><9231710.16573@mulga.cs.mu.OZ.AU> <1992Nov12.163801.29914@cs.kuleuven.ac.be> Organization: Penn State University Lines: 33