Newsgroups: comp.arch
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: '040 vs. SPARC (was: Next computer...)
Message-ID: <1990Feb12.202532.17784@utzoo.uucp>
Organization: U of Toronto Zoology
References: <8905@portia.Stanford.EDU> <160@zds-ux.UUCP> <38415@apple.Apple.COM> <2101@crdos1.crd.ge.COM> <19233@dartvax.Dartmouth.EDU> <604@bbxsda.UUCP>
Date: Mon, 12 Feb 90 20:25:32 GMT

In article <604@bbxsda.UUCP> scott@bbxsda.UUCP (Scott Amspoker) writes:
>Well, it doesn't take much to find instructions on a 680x0 that are
>not used by a C compiler.  However, my code tends to do a lot of
>structure accesses with pointers such as "pointer->field".  The
>68020 double-indirect-with-offset addressing mode is a real life
>saver and I haven't seen that on the few RISC machines I've used.

Have you measured the costs of doing without it?  Those fancy addressing
modes are usually quite slow.  Just because it's one addressing mode rather
than an instruction or two doesn't mean it's faster.
-- 
SVR4:  every feature you ever |     Henry Spencer at U of Toronto Zoology
wanted, and plenty you didn't.| uunet!attcan!utzoo!henry henry@zoo.toronto.edu