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From: davidsen@sixhub.UUCP (Wm E. Davidsen Jr)
Newsgroups: comp.benchmarks
Subject: Re: Ole Swang's benchmark: Sum of Harmonic Series
Message-ID: <2720@sixhub.UUCP>
Date: 23 Dec 90 17:06:05 GMT
References: <OLES.90Dec13213301@kelvin.uio.no> <44125@mips.mips.COM> <1990Dec19.004003.20667@dirtydog.ima.isc.com>
Reply-To: davidsen@sixhub.UUCP (bill davidsen)
Organization: *IX Public Access UNIX, Schenectady NY
Lines: 21

In article <1990Dec19.004003.20667@dirtydog.ima.isc.com> suitti@ima.isc.com (Stephen Uitti) writes:

| The do-while is faster.  On the 386/25 with 387, the "for" loop
| took 101.6 seconds, and the "do-while" loop took 99.8 seconds.

    Nope. You have changed both the loop type and the algorithm here.
The corresponding for loop would be

	for (n=100000; --n; ) { ... }

and the reason your version runs faster is that it avoids the compare,
not because it's a do-while.

  As in most benchmarks the effect of changing the program to make it
faster also means the numbers no longer compare to the old values in a
meaningful way.
-- 
bill davidsen - davidsen@sixhub.uucp (uunet!crdgw1!sixhub!davidsen)
    sysop *IX BBS and Public Access UNIX
    moderator of comp.binaries.ibm.pc and 80386 mailing list
"Stupidity, like virtue, is its own reward" -me