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Subject: Hash table question

Author: Sanjiv Karnataki

Date: 18:10:12 02/21/00


Hi,

Re hash tables:

a) I have noticed crafty uses two hash tables. why is that? Is it to handle
collisions by providing an extra bucket per key and thereby increasing hash
hits? If that is correct, does anyone here know how much benefit that provides
in terms of increase %hits?

b) Another thing about crafty: it stores 16 bytes in the hash table, 64 of which
are used to match the hashkey for verification. the other 64 are used to store
suggested move, score, score type etc. All very standard, _but_ while storing
the hash key it does not store it directly but instead stores the hashkey XOR
other 64bits of hash entry. What benefit does that provide?

Thank you in advance.

Sanjiv.



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