Frequently asked questions

I am getting an error with the message: “error: ‘cufftXtSetJITCallback’ was not declared in this scope”

Please, make sure you are including the correct cufftXt.h header, shipped with the cuFFT LTO preview package. This header can be dropped-in as replacement in the CUDA Toolkit ‘include’ folder.

I am getting an error with the message: “undefined reference to ‘cufftXtSetJITCallback’”

Similarly to the error above, please ensure you are linking against the correct version of libcufft.so / libcufft_static.a shipped in the cuFFT LTO preview package. The libraries can be dropped-in as replacement in the CUDA Toolkit ‘lib64’ folder.

My existing callback works fine without LTO (using cufftXtSetCallback) but planning fails when attempting to use LTO callbacks (cufftXtSetJITCallback)

There could be several reasons for this; the most likely cause is that inlining the callback function in the cuFFT kernel causes the kernel to run out of resources. Please, contact us with your feedback or use case so we can investigate further. We continue working to improve the amount of runtime linking information given by cuFFT to help users debug their application.