On Mar 27, 2008, at 6:02 AM, Prof Brian Ripley wrote: > On Thu, 27 Mar 2008, Alexy Khrabrov wrote: > >> Greetings -- which BLAS/LAPACk are used by R 2.6.2 with gfortran 4.2 >> on Leopard? > > Whatever you compile it against! It looks like you didn't consult the > R-admin manual before posting, so please do study it now. > > I believe that the binary versions distributed from CRAN are compiled > against vecLib: > > blacklark% otool -L libRblas.dylib > libRblas.dylib: > > /Library/Frameworks/R.framework/Versions/2.6/Resources/lib/ > libRblas.dylib > (compatibility version 0.0.0, current version 0.0.0) > /System/Library/Frameworks/vecLib.framework/Versions/A/vecLib > (compatibility version 1.0.0, current version 192.15.0) > /usr/lib/libgcc_s.1.dylib (compatibility version 1.0.0, > current > version 1.0.0) > /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, > current > version 88.3.9) >
Only for completeness, the CRAN binary currently ships with both vecLib-based Rblas (libRblas.veclib.dylib) and reference Rblas (libRblas.0.dylib) libraries. Which one is used can be influenced by setting libRblas.dylib symbolic link to one or the other (thanks to -- enable-BLAS-shlib option): cd /Library/Frameworks/R.framework/Resources/lib # for vecLib use ln -sf libRblas.vecLib.dylib libRblas.dylib # for R reference BLAS use ln -sf libRblas.0.dylib libRblas.dylib (I have added this info to the R for Mac FAQ). Cheers, Simon > since the recommended configure sequence is > > ./configure --with-blas='-framework vecLib' --with-lapack \ > --with-aqua --enable-R-framework > > (see the R-admin manual). > > Note that we prefer to have correct answers rather than fast ones, > and the > reference BLAS given by the default options is often more accurate and > more reliable (and so is the LAPACK distributed -- is is 3.1 so has > bugfixes against 3.0, but not the several incorrect bugfixes that some > Linux distributions have). So personally I only recommend using an > optimized BLAS when you need the performance (and few R sessions use > enough matrix algebra to do so). > > I've checked that --with-blas='-framework Accelerate' also works, > but I > see no real performance difference (and small differences can be > hard to > detect). (I tested i386, but x86_64 seems also to work.) > >> Macresearch.org instructs to use Accelerate, effectively switching >> from > > Hmm, actually it tells you Accelerate uses vecLib for BLAS/LAPACK. > > >> # LIBPATH = -L$/usr/local/lib >> # BLAS = -llapack -lf77blas -latlas > > That's always wrong: lapack should never be part of the BLAS. > >> to >> >> BLAS = -Wl,-framework -Wl,Accelerate >> >> -- per: >> >> http://macresearch.org/performance_tutorial_part_i_introducing_accelerate >> >> -- is this compatible with that packaged gfortran? > > Ultimately, we don't know. Different compilers can have different > argument-passing conventions on the same platform, so we would have to > look at every call (in vecLib, which is not AFAIK Open Source) on each > MacOS X architecture to *know*. > > This is not idle speculation: gcc3 and gcc4 ('Gnu Compiler > Collection') > have used different calling conventions on x86_64 on Linux and > Solaris, so > it is likely that not all Fortran compilers on x86_64 on MacOS are > compatible. (And AFAIR that is why there are vecLibg95c.c and > vecLibg95f.f in the R sources, and why there are configure tests in > R for > this.) > > >> Also -- if I want to try out xlf from IBM, how does that affect the >> choices of BLAS/LAPACK/Accelerate -- are they compatible or does xlf >> come with its own? (And why I can download trial versions of xlf for >> AIX/Linux but not for Mac?...) > > Ask IBM. > > -- > Brian D. Ripley, [EMAIL PROTECTED] > Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 > > _______________________________________________ > R-SIG-Mac mailing list > [email protected] > https://stat.ethz.ch/mailman/listinfo/r-sig-mac > > _______________________________________________ R-SIG-Mac mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-mac
