如何在Opencl内核的本地地址空间中传递数组

Question

I want to pass an array to the OpenCL kernel in local address space. But I get CL_invalid_VALUE .

int a[]={1,2,3,4,5};

We don't need to create a buffer to pass data in Local address space. So:

clSetKernelArg(kernel, 21, sizeof(int)*5,a);

In Kernel

__kernel void abc(__local int *a)
{} 

If i change the __local to __global , everything works fine. Please tell me how to do this.

Answer 1

You cannot pass anything to local memory from host.

The purpose of spesifying a local pointer in kernel parameters is to spesify the size of the local buffer at the runtime. Then on the clSetKernelArg call the 3rd parameter is the size and the 4th parameter must be NULL. Documentation

Assuming you are using GPU you can either pass it to Constant memory, initialize the local memory in the kernel if it's always the same or just pass it to global memory and then load it in the kernel to local memory preferably using async_work_group_copy.