> input.cl:34:106: error: call to 'mad' is ambiguous This looks to be caused by the lack of half precision builtins in libclc. GCN+ GPUs advertise support for cl_khr_fp16 in CLC but libclc is not ready yet. You can try my experimental cl_khr_fp16 branch: https://github.com/jvesely/libclc/tree/cl_khr_fp16