[DOC] How to compile runtime for aarch64 with opencl

Troubleshooting
#1

Hello,

I have created simple instruction how to create runtime with opencl

  • TVM_REPO is place where you clones tvm
  • install in the system llvm in version 12
  • clone https://github.com/KhronosGroup/OpenCL-Headers inside $TVM_REPO
  • time to find OpenCL library. I have found it, on target devices. Inside android, it’s usually /system/vendor/lib64/. I have placed it in folder $TVM_REPO/opencl_external_libs/system/vendor/lib64 
rm -rf $TVM_REPO/build-llvm12-arm-api-28-opencl/*
mkdir -p $TVM_REPO/build-llvm12-arm-api-28-opencl
cp $TVM_REPO/cmake/config.cmake $TVM_REPO/build-llvm12-arm-api-28-opencl
cd $TVM_REPO/build-llvm12-arm-api-28-opencl
sed -i 's/set(USE_OPENCL OFF)/set(USE_OPENCL ON)/g' config.cmake
sed -i 's/set(USE_LLVM OFF)/set(USE_LLVM \/usr\/lib\/llvm-12\/bin\/llvm-config)/g' config.cmake
cmake .. \
    -DUSE_RPC=ON \
    -DCMAKE_SYSTEM_NAME=Linux \
    -DCMAKE_SYSTEM_VERSION=1 \
    -DCMAKE_C_COMPILER=$ANDROID_NDK/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android28-clang \
    -DCMAKE_CXX_COMPILER=$ANDROID_NDK/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android28-clang++ \
    -DCMAKE_FIND_ROOT_PATH=$ANDROID_NDK/toolchains/llvm/prebuilt/linux-x86_64/ \
    -DCMAKE_FIND_ROOT_PATH_MODE_PROGRAM=NEVER \
    -DCMAKE_FIND_ROOT_PATH_MODE_LIBRARY=ONLY \
    -DMACHINE_NAME=armv7a-linux-gnu \
    -DOpenCL_INCLUDE_DIR=$TVM_REPO/OpenCL-Headers \
    -DOpenCL_LIBRARY=$TVM_REPO/opencl_external_libs/system/vendor/lib64/libOpenCL.so \
    -DUSE_LLVM=/usr/lib/llvm-12/bin/llvm-config
make -j4 runtime

Few notes:

  • do not use OpenCL headers/sdk from ubuntu repository - it doesn’t work
  • specify manually headers and from-phone library (DOpenCL_INCLUDE_DIR and DOpenCL_LIBRARY)
  • do not specify OpenCL-SDK(https://github.com/KhronosGroup/OpenCL-SDK) in cmake.config as USE_OPENCL value - it doesn’t work
  • make sure you have library and cross-compiler in the same architecture