title: work group barrier not working
body: <p>as a simple test to see whether or not the OpenCL 2.0 functions work for me, I've written a small kernel that calls work_group_barrier.  However, for the life if me, I can't figure out why the kernel becomes invalid.<br>
  Considering that the kernel will be valid if "barrier" is used, and work_group_barrier is just a renamed version of barrier, this doesn't make sense.  </p>
  
  <p>The kernel in question:</p>
  
  <pre><code>#pragma OPENCL EXTENSION cl_amd_printf : enable
  #pragma OPENCL EXTENSION cl_khr_subgroups : enable
  
  //pragmas go here
  #define TRUE 1
  #define FALSE 0
  
  __kernel void my_dumb_test(
  
  __global float *in0, 
  __global float *in1, 
  __global float *out
  ){
  
  int global_num = get_global_id(0);
  int local_num = get_local_id(0);
  int local_size = get_local_size(0);
  int global_size = get_global_size(0);
  int group_id = get_group_id(0);
  int group_num = get_num_groups(0);
  local int a;    
  int b = 2;
  //a = work_group_broadcast(b, local_num);
  //uint sub_group_size = get_sub_group_size();
  //printf("in0[%d]: %f\n", global_num, in0[global_num]);
  //printf("max sub group size: %d\n", sub_group_size);
  //work_group_barrier(CLK_GLOBAL_MEM_FENCE);
  //barrier(CLK_GLOBAL_MEM_FENCE);
  printf("global id: %d local id: %d group id: %d num groups %d\n", global_num, local_num, group_id, group_num);
  }
  </code></pre>
  
  <p>The funny thing is, the host-side OpenCL 2.0 functions work.  Using clCreateCommandQueueWithProperties returns with a success.  In the older versions of OpenCL, this function existed as clCreateCommandQueue.    CL_DEVICE_VERSION pings back OpenCL 2.0.  I'm running with the AMD Radeon R9 290X 4GB GDDR5, running Ubuntu 14.04, with the latest drivers, and the AMD-APP-SDK 3.0 beta.</p>
  
  <p>Any help is appreciated.  </p>