Use MKL FFTW interface instead of manually interfacing with MKL
Intel MKL provides an FFTW interface that means we should be able to remove all of our custom MKL code and just use a different header file. Explanations here:
- https://software.intel.com/en-us/mkl-developer-reference-c-fftw3-interface-to-intel-math-kernel-library
- https://software.intel.com/en-us/mkl-developer-reference-c-building-an-application-with-fftw3-interface-wrappers
From those links I think the --enable-intelfft
option would only need to check for the fftw3.h
file in the {prefix}/include/fftw/
directory - but I have no idea how to use automake...
/cc @adam-mercer