OpenCL application with 3 different kernels

0
votes

I just started with OpenCL and I want to port an app I have in CUDA. The problem I'm facing now is the kernel stuff. In CUDA I have all my kernel functions in the same file, on the contrary, OpenCL asks to read the file with the kernel source code and then do some other stuff.

My question is: Can I have one single file with all my kernel functions and then build the program in OpenCL OR I have to have one file for each of my kernel functions?

It would be nice if you give a little example.

1
cudaopencl

1 Answers

1
votes

The only difference between OpenCL and CUDA (in this specific regard) is that CUDA allows to mix device with host code in the same source file, while OpenCL requires you to load the program source as an external string and compile it at runtime.

But nevertheless it is absolutely no problem to put many kernel functions into a single OpenCL program, or even into a single OpenCL program source string. The kernels (say the C API kernel objects) themselves are then extracted from the program object using their respective function names.

pseudocode simplifying OpenCL's ugly C interface:

single OpenCL file:

__kernel void a(...) {}
__kernel void b(...) {}

C file:

source = read_cl_file();
program = clCreateProgramWithSource(source);
clBuildProgram(program);
kernel_a = clCreateKernel(program, "a");
kernel_b = clCreateKernel(program, "b");