2-d IMSL fft -> gfortran

[Peter Bromirski]

Hello,

    I have obtained a relatively old fortran code that uses 2-d IMSL  
FFT routines, forward and inverse.

Is there a gfortran implementation available that I can substitute?

I'm not a fortran programmer, so ...

As far as I can tell, the rest of the code is standard fortran, so  
any optimization flags to get this
code running as fast as possible would be helpful.

I'm running on a Mac OSX Tiger Intel 64-bit machine.

Thanks much.

---peter