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From: bengtl@maths.lth.se (Bengt Larsson)
Newsgroups: comp.arch
Subject: Re: Frequency of elementary functions (and other things)
Message-ID: <1991May21.010928.20316@lth.se>
Date: 21 May 91 01:09:28 GMT
Article-I.D.: lth.1991May21.010928.20316
References: <104811@sgi.sgi.com> <1991May19.080051.29716@lth.se> <12505@mentor.cc.purdue.edu>
Sender: newsuser@lth.se (LTH network news server)
Reply-To: bengtl@maths.lth.se (Bengt Larsson)
Organization: Lund Institute of Technology, Sweden
Lines: 41

In article <12505@mentor.cc.purdue.edu> hrubin@pop.stat.purdue.edu (Herman Rubin) writes:
>In article <1991May19.080051.29716@lth.se>, bengtl@maths.lth.se (Bengt Larsson) writes:
>> In article <12488@mentor.cc.purdue.edu> hrubin@pop.stat.purdue.edu (Herman Rubin) writes:
>> >The original thread, even cited, was the communication between integer and
>> >floating units.  Even such simple things as multiplication by variable
>> >integers are very likely as common as exponentiation.  
>> 
>> Give some qualified reason for it being likely common. 
>
>Other than having personally used it quite a bit, I cannot give you examples
>immediately.  

Figures.

>The use of the index of a do loop for floating point operations
>internally is not unusual.

"not unusual"? Prove it.

>Many function programs use table lookup.  This requires extracting the
>relevant bits from the floating point number, and frequently obtaining
>the difference.

Would be interesting to hear from someone who has _written_ such
"function programs" (assuming you mean subroutine libraries).

>Consider the sheer number of operations required on
>hardware without the communications capabilities.  

How big a number is "sheer", mr Rubin?

>How do you expect users who do not even know of the existence of the operations
>to use them?

By using a compiler which knows about them. More cost- and people effective
to do it that way, generally.

Bengt Larsson.
-- 
Bengt Larsson - Dep. of Math. Statistics, Lund University, Sweden
Internet: bengtl@maths.lth.se             SUNET:    TYCHE::BENGT_L