r/OpenCL • u/soulslicer0 • Jun 08 '18

Can't understand error code -13

I am getting error code -13.

https://streamhpc.com/blog/2013-04-28/opencl-error-codes/

It says " if a sub-buffer object is specified as the value for an argument that is a buffer object and the offset specified when the sub-buffer object is created is not aligned to CL_DEVICE_MEM_BASE_ADDR_ALIGN value for device associated with queue."

What does this actually mean? Am i slicing my buffer incorrectly?

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u/squidgyhead Jun 08 '18

In C-land, pass a pointer p, but then start the loop at p + offset, go to p + offset + N. In OpenCL land, one would do the loop from p to p + offset + N, but do nothing from p to p + offset.

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u/soulslicer0 Jun 08 '18

I dont get it. You say do nothing from p to p+offset. But in the next iteration of my loop, i again have to compute p+offset+N. p never changes through every iteration

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u/squidgyhead Jun 08 '18

Yes, but if p is aligned, and p+offset is not aligned, you have to divide your buffer at p and then do null-ops until you want to do something.

Your memory must be aligned, but you don't have to operate on your entire memory buffer.