Mail Archives: djgpp/1997/03/04/17:22:06
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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