Problems casting from int to uchar in OpenCL kernel

It is hard to tell if there is a problem with the algorithm or the compiler.

I recommend that you update to the new 14.1 version, which includes some bug fixes.

You can also try performing the matrix vector-product using uchar, but storing the final data as int? This may narrow down the problem and may be a work-around solution.

If these do not work, you can open a service request and share your code; then the Altera team can find the root cause of the problem.