NPU Integration Information

Steps

Environment Preparation

Besides basic Environment Preparation, HUAWEI HiAI DDK, which contains APIs (including building, loading models and calculation processes) and interfaces implemented to encapsulate dynamic libraries (namely libhiai*.so), is required for the use of NPU. Download DDK 100.510.010.010, and set the directory of extracted files as ${HWHIAI_DDK}. Our build script uses this environment viriable to seek DDK.

Build

Under the Linux operating system, one can easily build MindSpore Lite Package integrating NPU interfaces and libraries using build.sh under the root directory of MindSpore Source Code. The command is as follows. It will build MindSpore Lite’s package under the output directory under the MindSpore source code root directory, which contains the NPU’s dynamic library, the libmindspore-lite dynamic library, and the test tool Benchmark.

export MSLITE_ENABLE_NPU=ON
bash build.sh -I arm64 -j8

For more information about compilation, see Linux Environment Compilation.

Integration

Integration instructions

When developers need to integrate the use of NPU features, it is important to note:
- Configure the NPU backend. For more information about using Runtime to perform inference, see Using Runtime to Perform Inference (C++).
- Compile and execute the binary. If you use dynamic linking, please set environment variables to dynamically link libhiai.so, libhiai_ir.so, libhiai_ir_build.so, and libhiai_hcl_model_runtime.so. For example,
```
export LD_LIBRARY_PATH=mindspore-lite-{version}-android-{arch}/runtime/third_party/hiai_ddk/lib/:$LD_LIBRARY_PATH
```
  For more information about compilation, please refer to Compilation Output with compilation option -I arm64 or -I arm32.
Using Benchmark testing NPU inference

Users can also test NPU inference using MindSpore Lite’s Benchmark tool. Pass the build package to the /data/local/tmp/ directory of an Android phone equipped with NPU chips and test NPU inference using the Benchmark tool on the phone, as shown in the example below:
- Test performance
```
./benchmark --device=NPU --modelFile=./models/test_benchmark.ms --timeProfiling=true
```
- Test precision
```
./benchmark --device=NPU --modelFile=./models/test_benchmark.ms --inDataFile=./input/test_benchmark.bin --inputShapes=1,32,32,1 --accuracyThreshold=3 --benchmarkDataFile=./output/test_benchmark.out
```

For more information about the use of Benchmark, see Benchmark Use.

For environment variable settings, you need to set the directory where the libmindspore-lite.so (under the directory mindspore-lite-{version}-android-{arch}/runtime/lib) and NPU libraries (under the directory mindspore-lite-{version}-android-{arch}/runtime/third_party/hiai_ddk/lib/) are located, to ${LD_LIBRARY_PATH}.

Supported Chips

For supported NPU chips, see Chipset Platforms and Supported HUAWEI HiAI Versions.

Supported Operators

For supported NPU operators, see Lite Operator List.