Solved by tom in post #2 
              
              
                From what I recall, you want to disable the built-in fp16 ops for PyTorch, something like 
-DCUDA_HAS_FP16=1 -D__CUDA_NO_HALF_OPERATORS__ -D__CUDA_NO_HALF_CONVERSIONS__ -D__CUDA_NO_HALF2_OPERATORS__

or somesuch. 
Quite likely the flags PyTorch itself builds with are indicative for what you need. 
I…