Path: utzoo!attcan!uunet!husc6!bloom-beacon!athena.mit.edu!tada
From: tada@athena.mit.edu (Michael Zehr)
Newsgroups: comp.arch
Subject: Comiplers for RISC v. CISC
Message-ID: <7832@bloom-beacon.MIT.EDU>
Date: 6 Nov 88 00:53:10 GMT
References: <156@gloom.UUCP> <890@cps3xx.UUCP> <10194@cup.portal.com> <10722@cup.portal.com>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: tada@athena.mit.edu (Michael Zehr)
Organization: Massachusetts Institute of Technology
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In article <10722@cup.portal.com> bcase@cup.portal.com (Brian bcase Case) writes:

>The architecture has little if anything to do with this.  The compiler
>is a comparatively-meager one-time investment, and getting a good one
>is very important.  A good optimizing compiler is probably easier to
>write for a simple machine (e.g. RISC) than for a complex machine.

A "simple" machine?  To use RISC to it's full benefit you have to try and
cut CPU to memory data exchange, keep piplines well-filled, probably try 
to keep memory references in burst to increase cache hit rate.  

My guess is that's it's easier to write a working compiler for RISC than
for CISC, but a good optimizing compiler would have to be very complicated.

DISCLAIMER:  I don't write compilers.  I mostly just use them.  But I've read
a number of articles saying that the main advantage of RISC is only reached
when you have a complicated compiler that uses all the fancy hardware in the
machine.

Any comment by people who have written compilers for both RISC anc CICS???

-michael j zehr