Potential memory leak in FFT subroutines

[xcompact3d]

Potential memory leak in FFT subroutines

[mathrack]

A potential fix : mathrack@b796a12

[mathrack]

After investigation, the absence of "deallocate" statements should not leak memory because the array is not declared with the save attribute. https://community.intel.com/t5/Intel-Fortran-Compiler/Retention-of-allocated-memory-within-a-subroutine-that-is-called/td-p/1072829

[pbartholomew08]

It might still be worth doing deallocate:

1. It makes it explicit what is happening
2. Different compilers seem to treat SAVE (or lack of) differently from what I've read, so I wouldn't rely on it :)

[mathrack]

Makes sense. The fix I have proposed could be simplified : at the end of the subroutines, we could add

#ifndef OVERWRITE
if (allocated(wk1)) deallocate(wk1)
#endif

[pbartholomew08]

👍 looks good to me