After I ran the oclvanitygen.exe with a test address it came up this:

Available OpenCL platforms:

0: [Advanced Micro Devices, Inc.] AMD Accelerated Parallel Processing
  0: [Advanced Micro Devices, Inc.] Hawaii
  1: [Advanced Micro Devices, Inc.] Hawaii
  3: [Advanced Micro Devices, Inc.] Hawaii
  4: [GenuineIntel] Intel Core i5-4570 CPU @ 3.20GHz

But I don't know how to add the AMD gpu so that it will start working with it. What should I write in the command line for it to do it with the gpu?