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From: chris@mimsy.UUCP (Chris Torek)
Newsgroups: comp.arch
Subject: Re: What with these Vector's anyways?
Message-ID: <8013@mimsy.UUCP>
Date: Tue, 18-Aug-87 01:02:03 EDT
Article-I.D.: mimsy.8013
Posted: Tue Aug 18 01:02:03 1987
Date-Received: Wed, 19-Aug-87 04:33:31 EDT
References: <218@astra.necisa.oz> <142700010@tiger.UUCP> <363@astroatc.UUCP> <558@winchester.UUCP>
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 25
Keywords: scalar vs. vectors, benchmarks, Dhrystone, sorting

In article <558@winchester.UUCP> mash@mips.UUCP (John Mashey) writes:
>Actually an amusing test was using the Pascal version on an 8600, using the
>Pastel compiler, which avoids the VAX CALL instructions in favor of compiler-
>constructed sequences.

The copy of Pastel I have botches the compiler-constructed subroutine
calls, unfortunately.

>This is NOT exactly comparable, ....

Indeed.

It is also amusing to note that the faster VAXen generally have
less of a spread between `average' instruction time and CALLS+RET
instruction time.  The ratio is ~14:1 on the 780, meaning you could
execute ~14 `regular' instructions in the time it takes to do one
call and one return; on the 8600, it is more like ~4:1, I think.
(The 8600 is pipelined, which makes such ratios a bit of a joke.
Perhaps I should construct some test cases and run it on the various
VAXen we have around here: KA630, KA785, KA825, KA860---the 750s
have been officially decomissioned at last!---but there are some
downstairs I guess I could borrow....)
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 454 7690)
Domain:	chris@mimsy.umd.edu	Path:	seismo!mimsy!chris