WIP: Adding the guru interface

[psteinb]

some wrapper libraries for fftw only allow higher rigors than ESTIMATE when using the guru interface of fftw

[emmenlau]

Hi @psteinb ! I just found this PR and I'm curios which wrapper libraries require the guru interface for higher rigors than ESTIMATE?

[psteinb]

Hah, good that you asked. I had to check the docs again. So this is for ARM and one or two months back, I digged up the documentation that said so. I checked again to send you the link for reference: https://developer.arm.com/docs/101004/1910 Turns out, they now support the the full fftw interface plus the guru interface. So we can vote, if we should add the guru interface or not. AFAIK, it's mostly useful for special data layouts. So drop me a :thumbsup: if you want a guru interface. Otherwise, I drop this and check ARMPL again. ;)

[emmenlau]

Always nice to have a guru interface! And fftw evolves pretty slowly so there is not much maintenance overhead with the interface...