Atomic opertations

Hi,

I'm learning to program an FPGA using the OpenCL, in particular use DE1-Soc.

I'm trying to use atomic operations as atom_add, atom_inc ecc.

However, the compiler says: "ERROR: no matching function for call to 'atom_add.'"

I also tried using atomic_add, but with same result.

I also set# pragma OpenCL EXTENSION cl_khr_local_int32_base_atomics: enable.

What else should I do?