[R-sig-hpc] Choosing Intel MKL BLAS when compiling R
edd at debian.org
Wed Nov 2 16:35:00 CET 2011
On 2 November 2011 at 11:18, Simon Urbanek wrote:
| On Nov 2, 2011, at 10:57 AM, Michael Braun wrote:
| > Interesting. Incidentally, I mis-typed my link link below. Usually I link to MKL using -lmkl_rt -liomp5 (without the -lpthread). I'm still learning the vagaries of C++ and system libraries, but does this mean that I have been bypassing the Apple implementation? If Intel's libiomp5 does not have this problem, would that explain why my code seems to be working? Or is this an unrelated issue?
| I think you may be misunderstanding - what Dirk said is that MKL and OMP in R don't mix well and I said that we don't use OMP in R on OS X so it is irrelevant for OS X.
>From NEWS (and the text is still identical between r-devel and 2.14.0)
o configure looks for support for OpenMP and if found compiles R
with appropriate flags and also makes them available for use in
packages: see 'Writing R Extensions'.
This is currently experimental, and is only used in R with a
single thread for colSums() and colMeans(). Expect it to be more
widely used in later versions of R.
This can be disabled by the --disable-openmp flag.
It is my understanding that more of this will be forthcoming. Is that not correct?
Michael Rutter actually gets the credit in noticing the issue.
"Outside of a dog, a book is a man's best friend. Inside of a dog, it is too
dark to read." -- Groucho Marx
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