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From: bcase@apple.UUCP (Brian Case)
Newsgroups: comp.arch
Subject: Re: What with these Vector's anyways?
Message-ID: <1496@apple.UUCP>
Date: Tue, 18-Aug-87 12:45:07 EDT
Article-I.D.: apple.1496
Posted: Tue Aug 18 12:45:07 1987
Date-Received: Thu, 20-Aug-87 05:12:06 EDT
References: <218@astra.necisa.oz> <142700010@tiger.UUCP>
Reply-To: bcase@apple.UUCP (Brian Case)
Distribution: world
Organization: Apple Computer Inc., Cupertino, USA
Lines: 19
Keywords: scalar vs. vectors, benchmarks, Dhrystone, sorting

In article <567@gumby.UUCP> larry@gumby.UUCP (Larry Weber) writes:
>I wonder if any "dhrystone" runs actually have bugs in them
>but no one can tell because it computes nothing that can be tested.

This is a good point; I have one experience to relate.  While writing an
optimizing C compiler at AMD, I was a little worried that dhrystone was
running incorrectly.  To get a reasonably warm/fuzzy feeling, I put a line
like
	fprintf (outfile, "X\n");
where 'X' is a unique number (or a unique string, etc.), at each possible
fork in a branch (this includes procedure/function entrances, etc).  Then
I ran the program on the VAX and PC RT and simulated it on the Am29000.
In each case the outfile contained the same sequence of numbers.  At least
the *branching* behavior was equivalent in each case.  This seems like a
good first cut at correctness, and it should be possible to construct a
tool (based on a compiler front end) to insert the fprintf statements
automatically.  Is this reasonable or hairbrained?

    bcase