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Implement an old idea of Christian Tismer's: use polynomial division
instead of multiplication to generate the probe sequence. The idea is recorded in Python-Dev for Dec 2000, but that version is prone to rare infinite loops. The value is in getting *all* the bits of the hash code to participate; and, e.g., this speeds up querying every key in a dict with keys [i << 16 for i in range(20000)] by a factor of 500. Should be equally valuable in any bad case where the high-order hash bits were getting ignored. Also wrote up some of the motivations behind Python's ever-more-subtle hash table strategy.
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