title: OpenCl maximum work-items per compute unit
body: <p>I am writing an <code>OpenCL</code> code to find an optimum work-group size to have maximum occupancy on GPU. For this, I want a function that returns the maximum number of work-items per compute unit.</p>
  
  <p>Basically, I am deriving this from a <code>CUDA</code> code and I want an equivalent of <code>maxThreadsPerMultiProcessor</code>.
  In CUDA these were the values returned on device query:
  Maximum number of threads per multiprocessor:  2048
  Maximum number of threads per block:           1024</p>
  
  <p>In OpenCL:
  CL_DEVICE_MAX_WORK_GROUP_SIZE:    1024</p>
  
  <p>In CUDA it doesn't asks for kernel info to return this value.
  I need an equivalent function for OpenCL.
  Thanks in advance.</p>