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Rep:Re: [f-cpu] Where I can put my asm code

Don't forget to put your licence with it (GPL !).

But i answer your question here it could interrest lot of people :

1) What distance should be used for prefectch (how many cycle beteween a
prefetch and the effective load)

It depend, if you're in cache no need for it (you lose a cycle for
nothing). If it's not in cache you could take 150-200 cycle. But if the
distance is too small, depending of the implementation, you could also
lose one cycle (because the underlying system didn't find the adress in
cache and relaunch a read to the DRAM). If it's too far, the data should
have been trash by another data.

Then trash or not and cache hit or not depend on the cache type (size
and associativity) so it depend on the effective memory adress of the
manipulated data. That's why i didn't like prefetch...but preload.

2) Usualy a prefetch is a "silent load" so it behave the same for the
cache. A cache miss will generate a complete cache line load. The VM of
cedric will be used to calibrate such things (size of the line...).

3)There is no asm finish yet, so there is no common interface for macro,
as far as i know.

4)So ASM didn't try to mix instruction to hide latency. Before writting
such assembler, a dumb one should be finish.

I hope i have miss nothing.


-----Message d'origine-----
De: Thomas Lavergne <thomas.lavergne@laposte.net>
A: f-cpu@seul.org
Date: 13/06/02
Objet: Re: [f-cpu] Where I can put my asm code

Michael Riepe wrote:
 > On Thu, Jun 13, 2002 at 01:24:01AM +0200, Thomas Lavergne wrote:
 > [...]
 >>Is it possible to make sub-directory, I will try to make some code to
 >>simple image processing, and I think is better if all this code was
 >>same directory.
 > I have created a subdirectory for you. It's called `examples' (we can
 > rename it later).

Thanks, but I have no acces to this directory so I've put my file in a 
simple zip file : "Image.zip"

Can I have a personal directory to put sample well organised ?

I have put the first two sample, simple but it could be usefull for show

how the ISA work.


for the moment I've used my calling convention until we could make a
good standard cc well defined.

I will try to update it with updated version (see limitation in asm
files) and put another filter that allow applying convolution matrix to 
an image in few days. (so few have filter like blur, sharpen or emboss)

If you have any comment, mail me.

Thomas Lavergne                       "Le vrai rÍveur est celui qui rÍve
                                        de l'impossible."  (Elsa
d-12@laposte.net    ICQ:#137121910     http://assoc.wanadoo.fr/thallium/

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