Data.HashTable.hashInt seems somewhat sub-optimal
jmaessen at alum.mit.edu
Thu Aug 30 08:28:28 EDT 2007
On Aug 30, 2007, at 5:08 AM, Bulat Ziganshin wrote:
> Hello Jan-Willem,
> you may be interested to read hashing papers mentioned at
Not only did I read them, I tried out the Bob Jenkins hash function!
My conclusion is that for Data.HashTable we do not generally need a
strong hash; we need a reasonable hash that's cheap to evaluate. The
mulHi operation is cheap on most architectures (eg a single multiply
on 32-bit x86). Remember, for a hash table we're trading off hashing
cost with the cost of chain traversal. There are plenty of other
applications of hashing where we need to do a better job than this.
> Best regards,
> Bulat mailto:Bulat.Ziganshin at gmail.com
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