Re: New CRC algorithm: Slicing by 8 - Mailing list pgsql-hackers

From Tom Lane
Subject Re: New CRC algorithm: Slicing by 8
Date
Msg-id 23093.1161611418@sss.pgh.pa.us
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In response to Re: New CRC algorithm: Slicing by 8  (Jeremy Drake <pgsql@jdrake.com>)
Responses Re: New CRC algorithm: Slicing by 8  (Jeremy Drake <pgsql@jdrake.com>)
List pgsql-hackers
Jeremy Drake <pgsql@jdrake.com> writes:
> So at this point I realize that intel's compiler is optimizing the loop
> away, at least for the std crc and probably for both.  So I make mycrc an
> array of 2, and substript mycrc[j&1] in the loop.

That's not a good workaround, because making mycrc expensive to access
means your inner loop timing isn't credible at all.  Instead try making the
buffer array nonlocal --- malloc it, perhaps.
        regards, tom lane


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