From:	Tudor <tudor AT cam DOT org>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Floating Point vs. Fixed Point
Date:	Tue, 04 Mar 1997 14:01:30 -0800
Organization:	Communications Accesibles Montreal
Lines:	23
Message-ID:	<331C9BBA.4C95@cam.org>
References:	<5fhlm2$du6 AT alpha DOT hcst DOT com>
Reply-To:	tudor AT cam DOT org
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Bryan Murphy wrote:
> 
> I'm curious as to what advantages fixed point arithmatic has
> over floating point in relation to today's Pentiums and Pentium
> pro's.  I know traditionally Fixed point has been quicker, but
> is it losing that advantage?  Does MMX also promote the use of
> floating point over fixed point?  A lot of programs are being
> written using floating point now a days, and I'm curious if I
> should follow.
Yes, initially fixed point was faster than floating point (on 486's and
lower and especially on machines without a FPU/maths coprocessor).
But on a Pentium floating point is faster (ie. Shawn added floating
point opperations to Allegro; if you tartget pentium & up then use
floating point, else use fixed point).
Another example is Quake.
About MMX: I dunno.I heard you cannot use MMX instructions and floating
point instructions at the same time; they use the same pipe or
something.
cheers,
-- 
tudor 'at' cam 'dot' org
http://www.cam.org/~tudor
'This is Scott Nudds of the Borg. C is irrelevant.'

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