Slow MATMUL

[Tobias Burnus]

Am 12.12.2010 14:24, schrieb N.M. Maclaren:
> On Dec 12 2010, Tobias Burnus wrote:
>> If one tries the NETLIB version directly, the performance is improved:

(Directly = compiling the required files only with the same options - 
and linking with LTO [link-time optimization], which might help. - Here, 
LTO didn't.)

> One certainly can improve it, but the problems are doing so without
> introducing system dependencies or reserved names (*gemm).  I suspect
> that is what you really mean.

Well, gfortran has the option -fexternal-blas, which optionally replaces 
MATMUL by a call to a user-provided BLAS library, whether it is Netlib's 
BLAS, the one of ACML, the MKL or ESSL.

The question was more what one could do to improve the performance when 
not using (a vendor) BLAS for MATMUL but the standard libgfortran function.

Tobias