[ET Trac] [Einstein Toolkit] #516: Enable Vectorisation in McLachlan

Einstein Toolkit trac-noreply at einsteintoolkit.org
Thu Aug 25 09:40:02 CDT 2011


#516: Enable Vectorisation in McLachlan
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  Reporter:  barry.wardell          |       Owner:     
      Type:  enhancement            |      Status:  new
  Priority:  major                  |   Milestone:     
 Component:  EinsteinToolkit thorn  |     Version:     
Resolution:                         |    Keywords:     
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Comment (by eschnett):

 How do you know that SSE 4a was not used? This is autodetected in
 vectors-8-SSE2.h. It may be that this autodetection is faulty, of course,
 if e.g. the Intel and GNU compilers use different conventions here.

 Most of the vector instructions that we are using are defined in SSE 2.
 SSE 4.1 defines an instruction that allows a more efficient IfThen
 implementation, SSE 4a provides a more efficient implementation of a
 streaming partial store. Since you probably don't use streaming stores
 (Ian found them slower), it should make no difference whether SSE 4a is
 present or not.

-- 
Ticket URL: <https://trac.einsteintoolkit.org/ticket/516#comment:9>
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