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R Installation Manual - ATLAS BLAS guidance that is not in the current version

2 messages · Adler, Avraham, Brian Ripley

Original
Adler, Avraham
# 
Good afternoon.

I am trying to compile a version of Rblas.dll based on ATLAS for the Corei7. I had remembered that there was mention of which file to adjust and that "xerbla" needed to be removed from one of the outputs from the last time I tried a few years ago. The most recent version of the R Installation manual does not say anything about this. An older version (2.10 I believe) has the following text:

      Optionally, you can install a version of ATLAS
      (`math-atlas.sourceforge.net'
      (http://math-atlas.sourceforge.net/)) tuned to your system for
      fast linear algebra routines. Pre-built `Rblas.dll' for various
      Pentium and AthlonXP chips are available in the
      `windows/contrib/ATLAS' area on CRAN.  If you are building R from
      source, there are macros `USE_ATLAS' and `ATLAS_PATH' in the file
      `MkRules'.  Set `USE_ATLAS = YES' and `ATLAS_PATH' to where the
      ATLAS libraries are located.  You will need to make the libraries
      yourself(1): none of the binaries we have seen are compiled for
      the correct compiler.  Since R has its own `xerbla' it is best to
      delete that in ATLAS by
 
           ar d /path/to/libf77blas.a xerbla.o

Would it be possible to restore the above information to the next version of the manual for future reference, please?
 
Thank you,

Avraham Adler
3 days later
Brian Ripley
#
On 09/05/2012 19:54, Adler, Avraham wrote:
Corei7. I had remembered that there was mention of which file to adjust
and that "xerbla" needed to be removed from one of the outputs from the
last time I tried a few years ago. The most recent version of the R
Installation manual does not say anything about this. An older version
(2.10 I believe) has the following text:
No, as this is no longer supported (and various attempts to make it work 
have failed with incorrect results/segfaults).

We do support the use of the legacy Goto BLAS these days (64-bit only, 
but anyone who cares about performance will be using 64-bit).

As you have found in another thread, avoid over-optimizing code: the 
risk of incorrect answers is serious and the performance gains small.