Path: utzoo!attcan!uunet!munnari!mimir!hugin!augean!idall
From: idall@augean.OZ (Ian Dall)
Newsgroups: comp.arch
Subject: Re: A simple question on RISC
Message-ID: <419@augean.OZ>
Date: 14 Nov 88 06:06:44 GMT
References: <6544@xanth.cs.odu.edu> <75577@sun.uucp> <1618@imagine.PAWL.RPI.EDU>
Reply-To: idall@augean.OZ (Ian Dall)
Organization: Engineering Faculty, University of Adelaide, Australia
Lines: 17

In article <75577@sun.uucp> khb@sun.UUCP (Keith Bierman - Sun Tactical Engineering) writes:
>
> Or if they (wizzbang instructions) got used, it was
> so rare that it didn't matter. Or they got used, and it was slower
> than some combination of simple instructions. Or all of the above.

Can anyone tell me *why* some of these microcoded instructions were
slower than a combination of simpler instructions on the same machine?
I am not debating CISC vs RISK here since both cases run on the *same*
(cisc) machine.  If nothing else the second case must have resulted in
more memory accesses for instruction fetches. Was the difference
simply incompetence on the part of the micro code writer, or is there
some reason for this.
-- 
 Ian Dall           life (n). A sexually transmitted disease which afflicts
                              some people more severely than others.
idall@augean.oz