topic Re: fast CRC32 algorithm? in Intel® Integrated Performance Primitives

fast CRC32 algorithm?

robmaidment — Fri, 23 Nov 2007 12:33:42 GMT

Can anyone recommend a fast CRC32 algorithm? I thought the IPP might contain one but having downloaded it, it doesn't seem to.

thanks,

Rob

Re: fast CRC32 algorithm?

Vladimir_Dudnik — Fri, 23 Nov 2007 13:01:37 GMT

Rob, what do you mean 'it doesn't seem to'?

Did you find ippsCRC32_8u function in ippDC library?

Regards,
Vladimir

Re: fast CRC32 algorithm?

robmaidment — Fri, 23 Nov 2007 16:15:18 GMT

Vladimir

I meant I couldn't find any mention in the documentation. Obviously I wasn't looking hard enough, I've found it now and carried out some tests with it.

It's no faster than my home-grown version, but then I guess there's only so much you can do with a CRC32 generator.

I'm using it to create hashes of strings to avoid string comparisons. Is there a more efficient alternative do you think?

Thanks for you help,

Rob

Re: fast CRC32 algorithm?

Vladimir_Dudnik — Fri, 23 Nov 2007 16:34:00 GMT

We have two functions to calculate CRC32, one is specific for BZ2 (ippsCRC32_BZ2_8u)and other is general purpose ippsCRC32_8u

You are right, SSE will not help much in such calculations, so it may make sense to implement it inline to avoid function call overhead when you work on small amount of data.

Vladimir