[Ffmpeg-devel] fastmemcpy in ffmpeg

[Ulrich von Zadow]

Gunnar von Boehn wrote:
> Hi Ulrich,
> 
> Ulrich von Zadow wrote:
>> Gunnar von Boehn wrote:
>>
>>> Hi
>>>
>>> Diego Biurrun wrote:
>>>
>>>> On Mon, Sep 25, 2006 at 10:47:40AM +0200, Michel Bardiaux wrote:
>>>>
>>>>
>>>>> Silvano Galliani (kysucix) wrote:
>>>>>
>>>>>
>>>>>> Is there some plan to include and use fastmemcpy implementation from
>>>>>> mplayer?
>>>
>>> I've once collected and benchmarked a number of memcopy routines both
>>> for x86 and PowerPC.
>>>
>>> http://www.greyhound-data.com/gunnar/glibc/
>>
>>
>> I only found ppc data on the site, which, while very interesting, is
>> only half of what you promised ;-). Did I just miss a link?
> 
> The charts of the detailed benchmarks only shows PPC CPUs, that is
> right. But it did some tests on x86 (Intel/AMD) CPUs as well.
> 
> This overview chart shows the difference between Linux memcpy and
> optimized version on different CPUs including x86.
> http://www.greyhound-data.com/gunnar/glibc/membench_memcpy.gif
> 
> A simple but very effective way to double the memcopy speed
> is to prefetch (stream) the source in while copying. Just by
> adding one prefetch instruction to the normal Linux memcpy you can speed
> it up a lot 50%.

I couldn't find the optimized intel code in the downloads - is it
possible to get it?

Regards,

  Uli