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From: nfs@notecnirp.Princeton.EDU (Norbert Schlenker)
Newsgroups: comp.os.minix
Subject: Re: Dhrystone 2.1 sample run
Message-ID: <20135@princeton.Princeton.EDU>
Date: 10 Oct 89 12:24:36 GMT
References: <24988@louie.udel.EDU> <2457@ucsfcca.ucsf.edu> <3545@ast.cs.vu.nl> <3593@ast.cs.vu.nl> <2482@ucsfcca.ucsf.edu>
Sender: news@princeton.Princeton.EDU
Reply-To: nfs@notecnirp.UUCP (Norbert Schlenker)
Organization: Dept. of Computer Science, Princeton University
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In article <2482@ucsfcca.ucsf.edu> root@cca.ucsf.edu (Systems Staff) writes:
>In article <3593@ast.cs.vu.nl>, ast@cs.vu.nl (Andy Tanenbaum) writes:
>> ...
>> I think the interface of the first dhrystone version that simply printed
>> the answer is much nicer.  Any objections if I delete all the garbage in
>> the MINIX version?
>
>Under no circumstances make such deletions!
>
>This code is needed to make sure that compilers don't perform sleight-of-
>hand and make a lot of the computation vanish. They consider anything
>that's computed but not used as irrelevant and subject to deletion.
> ...
> Thos Sumner       Internet: thos@cca.ucsf.edu

Before this goes any further, I'd like to point out that a lot of Minix
users use the ACK compilers.  The changes from Dhrystone 1.1 to 2.1 were
made solely to defeat optimizations by clever compilers, a category into
which the ACK compilers do not fall.  The difference on my machine between
the two versions is minor, since ACK is not good at detecting or removing
dead code.  Those who run gcc on ST's might see a difference.

I actually prefer 1.1, since it doesn't produce 50 lines of output, it
runs for more than 32767 iterations, and it DOESN'T USE FLOATING POINT to
calculate its results.

Norbert

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