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SubjectRe: Question: Using floating point in the kernel
In article <Pine.LNX.3.95.1000920141233.9629A-100000@chaos.analogic.com> you wrote:
> On Wed, 20 Sep 2000, Timur Tabi wrote:

> Well the code does a fnsave. Somebody never looked at the damn book! it
> takes 143 clocks for this, plus at least 3 for fwait. Then it sets a
> flag to let return code 'know' if the context has to be restored. This
> code `exists` sort of like moss. I don't think it is ever executed and
> if it is, you get to keep both broken pieces.

+--------------------------+-------------+
| non-MMX clear_page | 2382 cycles |
| MMX clear_page | 874 cycles |
+--------------------------+-------------|
| non-MMX copy_page | 4569 cycles |
| MMX copy_page | 1748 cycles |
+--------------------------+-------------+

(On a AMD Duron 700Mhz with 2 133Mhz DIMMs)

The numbers above don't include the fnsave. But as you can see the 150
cycles you mention above are still worth it.

Greetings,
Arjan van de Ven


< The test program is available at http://www.fenrus.demon.nl/athlon.c >
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