Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!sun-barr!rutgers!cbmvax!jesup
From: jesup@cbmvax.commodore.com (Randell Jesup)
Newsgroups: comp.arch
Subject: Re: Compilers and efficiency
Message-ID: <21033@cbmvax.commodore.com>
Date: 29 Apr 91 04:35:13 GMT
References: <27fa3350.6bc2@petunia.CalPoly.EDU> <9782@mentor.cc.purdue.edu> <4082@batman.moravian.EDU> <11411@mentor.cc.purdue.edu>
Reply-To: jesup@cbmvax.commodore.com (Randell Jesup)
Organization: Commodore, West Chester, PA
Lines: 20

In article <11411@mentor.cc.purdue.edu> hrubin@pop.stat.purdue.edu (Herman Rubin) writes:
>If this was the case, the hardware was deficient.  To a mathematician, floating
>point arithmetic is a complicated version of fixed point arithmetic.  This is a
>point which the RISC designers do not see; the chip real estate for doing good
>integer arithmetic is already there in the floating point stuff, and the design
>should be such as to use it.  Floating point arithmetic uses fixed point 
>internally, so this would not be a problem AT THE TIME OF THE DESIGN OF THE
>ARCHITECTURE.  It is a problem afterward.

	The RPM-40 used the floating point HW for integer multiple and divide,
and I'm certain at least a few others have also.  However, don't do this if
you have only a couple FP registers (a problem the rpm40 had).

-- 
Randell Jesup, Keeper of AmigaDos, Commodore Engineering.
{uunet|rutgers}!cbmvax!jesup, jesup@cbmvax.commodore.com  BIX: rjesup  
Disclaimer: Nothing I say is anything other than my personal opinion.
Thus spake the Master Ninjei: "To program a million-line operating system
is easy, to change a man's temperament is more difficult."
(From "The Zen of Programming")  ;-)