Re: [R] when can we expect Prof Tierney's compiled R?

From: Peter Dalgaard <p.dalgaard_at_biostat.ku.dk>
Date: Thu 21 Apr 2005 - 04:24:15 EST

Luke Tierney <luke@stat.uiowa.edu> writes:

> Vectorized operations in R are also as fast as compiled C (because
> that is what they are :-)). A compiler such as the one I'm working on
> will be able to make most difference for non-vectorizable or not very
> vectorizable code. It may also be able to reduce the need for
> intermediate allocations in vectorizable code, which may have other
> benefits beyond just speed improvements.

Actually, it has struck me a couple of times that these operations are not as fast as they could be, since they are outside the scope of fast BLAS routines, but "embarrassingly parallel" code could easily be written for the relevant hardware. Even on uniprocessor systems there might be speedups that the C compiler cannot find (e.g. because it cannot assume that source and destination of the operation are distinct).

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard@biostat.ku.dk)             FAX: (+45) 35327907

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Received on Thu Apr 21 05:21:10 2005

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