RFR: 8071571: Move substring of same string to slow path

Martin Buchholz martinrb at google.com
Wed May 13 23:12:47 UTC 2015


On Wed, May 13, 2015 at 4:06 PM, Vitaly Davidovich <vitalyd at gmail.com>
wrote:

> :) The branch avoiding versions may cause data dependence hazards whereas
> the branchy one just has branches but assuming perfectly predicted (and
> microbenchmarks typically are) can pipeline through.  Ivan, could you
> please post the asm here? Assuming you guys are interested in investigating
> this further.
>
there might be a new rule of thumb there: only eliminate branches if they
are unlikely to be predicted.



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