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From: dswartz@bigbootay.sw.stratus.com (Dan Swartzendruber)
Newsgroups: comp.arch
Subject: Re: Re: a style question
Message-ID: <2580@lectroid.sw.stratus.com>
Date: 3 Oct 90 19:48:07 GMT
References: <1990Oct2.151644.1581@phri.nyu.edu> <1300002@hp-ptp.HP.COM> <2572@lectroid.sw.stratus.com> <41898@mips.mips.COM>
Sender: usenet@lectroid.sw.stratus.com
Reply-To: dswartz@bigbootay.sw.stratus.com (Dan Swartzendruber)
Organization: Stratus Computer, Software Engineering.
Lines: 30

In article <41898@mips.mips.COM> mash@mips.COM (John Mashey) writes:
:In article <2572@lectroid.sw.stratus.com> dswartz@bigbootay.sw.stratus.com (Dan Swartzendruber) writes:
::Can you say "nitpicking over whether to do == or < is silly micro-level
::optimization which can't even be relied on to behave the same from one
::machine to the next"?  I knew you could!
:
:At the code level, this is probably true, although it certainly is the
:case that there are fundamental computer system design reasons why
:== might be faster than <.  Whether these reasons show up in any
:given computer architecture is another issue, but certainly, if you care,
:the == or != tests are likely to be equal or faster on many machines,
:or equal on others, but seldom slower.
:It probably doesn't matter most places, except in some technical code
:with short loops with many iterations.

My point was only that I felt that any performance advantage (one or
two clocks was bandied about) is grossly outweighed by the rest of the
loop, and given that, I tend to prefer the < syntax (since it is pretty
much required for floating-point variables.)

:-- 
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--

Dan S.