cltorch googlenet.lua: attempt to index global 'cudnn' (a nil value)

[yige-hu]

Operating System: Ubuntu 16.04.3 LTS, Linux kernel 4.13.0
GPU: AMD RX 580
ROCm backend.

~/convnet-benchmarks/cltorch$ th imagenet_winners/benchmark.lua 
libthclnn_searchpath    /storage/home/yige/torch-cl/install/lib/lua/5.1/libTHCLNN.so
Running on device: gfx803
Using Advanced Micro Devices, Inc. , OpenCL platform: AMD Accelerated Parallel Processing
Using OpenCL device: gfx803
ModelType: OverFeat[fast]       Kernels: clnn   Input shape: 128x3x231x231
clnn                                    :updateOutput():     673.86
clnn                                 :updateGradInput():     344.01
clnn                               :accGradParameters():     480.27
clnn                                           :Forward:     673.86
clnn                                          :Backward:     824.27
clnn                                             :TOTAL:    1498.13
ModelType: AlexNet      Kernels: clnn   Input shape: 128x3x224x224
clnn                                    :updateOutput():     311.44
clnn                                 :updateGradInput():     158.93
clnn                               :accGradParameters():     623.55
clnn                                           :Forward:     311.44
clnn                                          :Backward:     782.48
clnn                                             :TOTAL:    1093.92
ModelType: VGG Model-A  Kernels: clnn   Input shape: 64x3x224x224
clnn                                    :updateOutput():     671.76
clnn                                 :updateGradInput():     508.20
clnn                               :accGradParameters():    1174.33
clnn                                           :Forward:     671.76
clnn                                          :Backward:    1682.52
clnn                                             :TOTAL:    2354.29
/storage/home/yige/torch-cl/install/bin/luajit: ./imagenet_winners/googlenet.lua:33: attempt to index global 'cudnn' (a nil value)
stack traceback:
        ./imagenet_winners/googlenet.lua:33: in function <./imagenet_winners/googlenet.lua:30>
        imagenet_winners/benchmark.lua:34: in main chunk
        [C]: in function 'dofile'
        ...e/torch-cl/install/lib/luarocks/rocks/trepl/scm-1/bin/th:145: in main chunk
        [C]: at 0x00405e90