Hi Liam,
Today, I had some time to take a look at the (slow) speed of the FFT tests. I found that having the tests as is and adding declarations only gives a speed-up of (barely) 10%. I think I'll need to thoroughly rewrite the tests to find/solve the problem. I need to do this anyway, since a small number of tests still keeps on failing and I haven't been able to track down _that_ problem yet.
As such, I'll begin "from scratch", rewriting each test. This might take some time, and due to a shortage of that due to work-related things, this might take even longer than anticipated. This situation is quite annoying since, naturally, the FFT tests should be enabled in the gsll-tests package, and not only for completeness. I'll do my best allocating time to this.
Regards, Sumant