What is special about cl specific data types?

OpenCL
1

Hi folks

I’ve just started learning OpenCL. I see many cl specific data types such as cl_int' andcl::vector’ (I am using the C++ bindings). How are these data types different from the standard ones?

Is it that only the cl data types can be used when talking to devices?

Thanks

2

C99 does not guarantee that any basic data types such as “int”, “long”, etc. have a specific size. The cl_ data types are guaranteed to have specific sizes and sign representations, and additionally they are guaranteed to match the OpenCL C (kernel) data types.

For example, “int” could be 16-bits while “cl_int” is guaranteed to be a 32-bit signed integer in two’s complement format.

Whenever you use OpenCL, please stick to cl_ data types.

3

Thanks David. That makes a lot of sense. I see now that it’s all mentioned in the OpenCL spec. I’ll be careful to look at that when deciding what datatypes to use.