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From: cik@l.cc.purdue.edu (Herman Rubin)
Newsgroups: comp.arch
Subject: Re: Double Width Integer Multiplication and Division
Summary: Some comments
Message-ID: <1370@l.cc.purdue.edu>
Date: 30 Jun 89 12:01:48 GMT
References: <1035@aber-cs.UUCP>
Organization: Purdue University Statistics Department
Lines: 31

In article <1035@aber-cs.UUCP>, pcg@aber-cs.UUCP (Piercarlo Grandi) writes:
> In article <1989Jun26.195044.4197@cs.rochester.edu> crowl@cs.rochester.edu
> (Lawrence Crowl) writes:
> 
> 	[1] You are not supposed to write assembler programs on a RISC
> 	    machine. The compilers have sophisticated algorithms to generate
> 	    "optimal" multiplication/division out of simpler instructions.

I find this attitude arrogant.  Neither you nor anyone else knows what 
complicated operations I want to do.  Why should you try to make it 
difficult for me to use the power of the computer?

> 	[2] Fixed point and the "muldiv()" idea to me look very much in the
> 	    RISC philosphy of minimalism. Fixed point, and multiple precision
> 	    integer arithmetic, are in many many cases preferable to floating
> 	    point and its complexities. Too bad that mathematicians are lulled
> 	    in a false sense of familiarity by floating point's "scientific
> 	    notation" and apparent support for real numbers.

Do any mathematicians take this attitude?  Maybe if their only knowledge of
computers comes from HLLs and they swallow the hype.  Outside of the field
of numerical analysis, the "scientific notation" is rarely used in mathematics.

Mathematicians who know that floating point numbers are, in reality, only
approximations to real numbers will not be so confused.  And good numerical
analysts do not make this confusion.  In fact, mathematicians complain that
they are only offered limited precision floating point.
-- 
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907
Phone: (317)494-6054
hrubin@l.cc.purdue.edu (Internet, bitnet, UUCP)