Re:LFortran: Modern interactive LLVM-based Fortran compiler
by antoinealb on Friday July 03, 2020 @04:54AM
(#23722284)
You can define EIGEN_USE_BLAS and then Eigen will delegate matrix operations to BLAS routines (such as gemm) instead of its own engine [0]. Then, you could link your program to a BLAS implementation written in Fortran.
However, when I last researched this for my previous work, OpenBLAS was the fastest open source implementation and is written in a mix of C and assembly, not Fortran. The repository contains quite a lot of Fortran, but it is mostly for the LAPACK implementation, which is not part of BLAS.
In our testing we got a nice speedup of our signal processing pipeline when enabling EIGEN_USE_BLAS, but this was on ARM64, so your experience may differ.
However, when I last researched this for my previous work, OpenBLAS was the fastest open source implementation and is written in a mix of C and assembly, not Fortran. The repository contains quite a lot of Fortran, but it is mostly for the LAPACK implementation, which is not part of BLAS.
In our testing we got a nice speedup of our signal processing pipeline when enabling EIGEN_USE_BLAS, but this was on ARM64, so your experience may differ.
[0] https://eigen.tuxfamily.org/dox/TopicUsingBlasLapack.html