问题
i am new to CUDA and is trying to learn the usage. can someone please help. i have the following in the main function (i am in visual studio and my source and header files are .cu and .cuh respectively)
thrust::device_vector<float> d_vec(100);
kernel<<<100,1>>>(d_vec);
and then in the kernel i have
template <typename T> __global__ kernel(thrust::device_vector<T> d_vec)
{ int tid = threadIdx.x + blockIdx.x*blockDim.x;
T xxx = 3.0;
d_vec[tid] = xxx;
}
my objective is to call the kernel once with float and once with double. Also note that in this simple example i have variable xxx (which in my real case is some computation producing double or float numbers).
and i get two error:
1> calling a __host__ function (operator =) from a __global__ function is not allowed
2> calling a __host__ function (operator []) from a __global__ function is not allowed
so i guess "[]" and "=" in "d_vec[tid] = .." is the problem. But my question is how do i access the device vector inside my kernel. Can someone please clarify what is the correct procedure and what i am doing wrong. thanks in advance
回答1:
thrust::device_vector objects/references can not be used as kernel parameters. You could use raw pointers to pass the device vector data.
thrust::device_vector<float> d_vec(100);
float* pd_vec = thrust::raw_pointer_cast(d_vec.data());
kernel<<<100,1>>>(pd_vec);
and here's the prototype of the kernel
template <typename T> __global__ kernel(T* pd_vec)
You Q is similar to this one. how to cast thrust::device_vector<int> to raw pointer
来源：https://stackoverflow.com/questions/14443001/thrustdevice-vector-in-cuda