Re: netcdf-3.6.2-beta6 released - last beta release of 3.6.2

• To: robl@xxxxxxxxxxx (Robert Latham)
• Subject: Re: netcdf-3.6.2-beta6 released - last beta release of 3.6.2
• From: Russ Rew <russ@xxxxxxxxxxxxxxxx>
• Date: Fri, 19 Jan 2007 23:49:02 -0700

Hi Rob,

> > Features of the 3.6.2 release (from the netCDF FAQ):
> > 
> >     * as much as 22% speedup for applications accessing floats or ints
> >     on little-endian platforms.
> 
> Apologies if this isn't the right forum, but this item really caught
> our attention.  As someone working on parallel-netcdf, I'd sure like
> to hear more about anything that speeds things up 22%.  What did you
> do to achieve this? ...

This resulted from unrolling a loop in the function swapn4b() in
libsrc/ncx.c (the source was actually libsrc/ncx.m4).  If your
compiler already unrolls loops aggressively, you may not see this much
speedup.

--Russ

_____________________________________________________________________

Russ Rew                                         UCAR Unidata Program
russ@xxxxxxxxxxxxxxxx                     http://www.unidata.ucar.edu

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• References:
  • Re: netcdf-3.6.2-beta6 released - last beta release of 3.6.2
    • From: Robert Latham