How to make a kernel function which callable from both the host and device?

Question

The following trial presents my intention, which failed to compile:

__host__ __device__ void f(){}

int main()
{
    f<<<1,1>>>();
}
         


        

Answer 1

The tutorial you are looking at is so old, 2008? It might not be compatible with the version of CUDA you are using.

You can use __global__ and that means __host__ __device__, this works:

__global__ void f()
{
    const int tid = threadIdx.x + blockIdx.x * blockDim.x;
}

int main()
{
    f<<<1,1>>>();
}