Re: [OMPI devel] RFC: improve the hash function used by opal_hash_table_t

2013-06-11 Thread George Bosilca
On Jun 12, 2013, at 00:22 , Nathan Hjelm wrote: > Though a hardware accelerated crc32 (if available) would probably work great > as well. http://google-opensource.blogspot.fr/2011/04/introducing-cityhash.html with code available under MIT @ https://code.google.com/p/cityhash/ George.

Re: [OMPI devel] RFC: improve the hash function used by opal_hash_table_t

2013-06-11 Thread Nathan Hjelm
I think as long as we are updating this we might as well add a performant hash function. I see Murmur2 is 32-bit and has a public domain implementation: https://code.google.com/p/smhasher/source/browse/trunk/MurmurHash2.cpp Since Murmur2 hashes in 4-byte blocks I expect it probably would perform

Re: [OMPI devel] RFC: improve the hash function used by opal_hash_table_t

2013-06-11 Thread George Bosilca
The one-at-the-time version computes on chars, if the performance of the hash function is a critical element in the equation then you will be better off avoiding its usage. I would suggest going with Murmur (http://en.wikipedia.org/wiki/MurmurHash) instead, which is faster and perform well in r