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List:       freebsd-hackers
Subject:    Re: memmem small optimalisation
From:       Joerg Sonnenberger <joerg () britannica ! bec ! de>
Date:       2012-02-24 8:11:51
Message-ID: 20120224081150.GB23692 () britannica ! bec ! de
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On Thu, Feb 23, 2012 at 05:34:03PM -0800, Xin Li wrote:
> Did you benchmarked the change?  Changes like this has to be done very
> carefully since it's possible that the extra time spent on addition
> and subtractions, when multiple by the length of the "long" string,
> may actually defeat the benefit of one less byte worth memory compare
> because the effect of CPU's data cache.

More importantly, if the input was originally aligned, the additional
byte is ~free.

Joerg
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