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Re: [colorforth] Intellasys question for Jeff Fox


On Fri, May 23, 2008 at 05:21:14PM -0700, Jeff Fox wrote:
> Dr. Monvelishsky wrote a CORDIC function in machineforth
> for our ANS P21forth in 1992 which also ran on F21 with
> a small mod.  I recall that I was impressed with the fact
> that p21 running Michael's code was 50x faster than Intel's
> 387 coprocessor on these transcendental functions at the
> time. Michael wrote a CORDIC for SEAforth so long ago that
> it probably needs to be updated now.  Such things will be
> included when more libraries are published.

That doesn't tell the whole story. Intel's result was for more
than 50 % the nearest presentable float, and never more than
the machine precision (epsilon) off.

So to complete the picture:
        How precise was the cordic?

(Todays Intel's can do a cosine in a couple of cycles of 284 pS.
It is not fair to compare the F21 to that, but indeed the world has
moved on.)

> Best Wishes

Groetjes Albert
--
Albert van der Horst, UTRECHT,THE NETHERLANDS
Economic growth -- like all pyramid schemes -- ultimately falters.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

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