Hi,

You use unsigned long instead of uint64_t, because GMP forces you to do so.

I had the same problem with GSL , and I solved it writing a wrapper around its functions, and adding some compile-time assertions to ensure that the types are the same.

I would like to show you an example of what I did, so that if you like it, you can apply it to your code. I think it will look better with uint64_t.

Assertions:
https://github.com/alejandro-colomar/libalx/blob/master/inc/libalx/base/assert/assert.h

Wrappers:
https://github.com/alejandro-colomar/libalx/blob/master/inc/libalx/extra/gsl/statistics/mean.h

You could either write wrappers (I would do that), or just assert that the types are the same and use the typedefs directly.

When compiling the gpuworker, I'm getting a fatal error from CL/cl.h being missing. There isn't any file in the repository for this file, so how do I get it?

cc -std=c89 -pedantic -Wall -Wextra -march=native -O3 -D_XOPEN_SOURCE=500 -DCL_TARGET_OPENCL_VERSION=220 -DCL_USE_DEPRECATED_OPENCL_1_2_APIS -DSIEVE_LOGSIZE=16 -DTASK_UNITS=16 -DUSE_ASYNC_CALL gpuworker.c -lOpenCL -o
gpuworker
gpuworker.c:11:10: fatal error: CL/cl.h: No such file or directory
11 | #include <CL/cl.h>
| ^~~~~~~~~
compilation terminated.
make: *** [<builtin>: gpuworker] Error 1

The website (collatz-problem.org) seems to have a glitch that's making the assignment percentage show as more than 100%. Also, the time left for verification is stuck on Calculating...

Since the website isn't clear, I'm just wondering if this project is distributed (such as BOINC) or if this project just runs on your computer?

Would you be able to share the code for the results in your new paper? It was very interesting.
Thanks.