Static Library Cropper Tool

Overview

MindSpore Lite provides the libmindspore-lite.a static library cropping tool for runtime, which can filter out the operators in the ms model, crop the static library files, and effectively reduce the size of the library files.

The operating environment of the library cutting tool is x86_64, and currently supports the cropping of CPU or GPU operators, and the GPU library supports setting CMAKE’s MSLITE_GPU_BACKEND to opencl.

Environment Preparation

To use the Cropper tool, you need to prepare the environment as follows:

Compilation: The code of the Cropper tool is stored in the mindspore/lite/tools/cropper directory of the MindSpore source code. For details about the build operations, see the Environment Requirements and Compilation Example in the build document to compile version x86_64.
Run: Obtain the cropper tool and configure environment variables. For details, see Output Description in the build document.

Parameter Description

The command used for crop the static library based on Cropper is as follows:

./cropper [--packageFile=<PACKAGEFILE>] [--configFile=<CONFIGFILE>]
          [--modelFile=<MODELFILE>] [--modelFolderPath=<MODELFOLDERPATH>]
          [--outputFile=<MODELFILE>] [--help]

The following describes the parameters in detail.

Parameter	Attribute	Function	Parameter Type	Default Value	Value Range
`--packageFile=<PACKAGEFILE>`	Mandatory	The path of the `libmindspore-lite.a` to be cropped.	String	-	-
`--configFile=<CONFIGFILE>`	Mandatory	The path of the configuration file of the cropper tool. The file path of `cropper_mapping_cpu.cfg` or `cropper_mapping_gpu.cfg` needs to be set to crop the CPU or GPU library.	String	-	-
`--modelFolderPath=<MODELFOLDERPATH>`	Optional	The model folder path, according to all the `ms` models existing in the folder for library cropping. `modelFile` or `modelFolderPath` parameters must be selected.	String	-	-
`--modelFile=<MODELFILE>`	Optional	The model file path is cut according to the specified `ms` model file. Multiple model files are divided by `,`. `modelFile` or `modelFolderPath` parameters must be selected.	String	-	-
`--outputFile=<OUTPUTFILE>`	Optional	The saved path of the cut library `libmindspore-lite.a`, it overwrites the source file by default.	String	-	-
`--help`	Optional	Displays the help information about the `cropper` command.	-	-	-

The configuration file cropper_mapping_cpu.cfg cropper_mapping_gpu.cfg exists in the tools/cropper directory in the mindspore-lite-{version}-linux-x64 package.

Example

The Cropper tool obtains the operator list by parsing the ms model, and crop the libmindspore-lite.a static library according to the mapping relationship in the configuration file configFile.

Pass in the ms model through the folder, and pass the folder path where the model file is located to the modelFolderPath parameter to crop the libmindspore-lite.a static library of arm64-cpu.

./cropper --packageFile=/mindspore-lite-{version}-android-aarch64/runtime/lib/libmindspore-lite.a --configFile=./cropper_mapping_cpu.cfg --modelFolderPath=/model --outputFile=/mindspore-lite/lib/libmindspore-lite.a

This example will read all the ms models contained in the /model folder, crop the libmindspore-lite.a static library of arm64-cpu, and the cropped libmindspore-lite.a static library will be saved to /mindspore-lite/lib/ directory.

Pass in the ms model by file, pass the path where the model file is located to the modelFile parameter, and crop the libmindspore-lite.a static library of arm64-cpu.

./cropper --packageFile=/mindspore-lite-{version}-android-aarch64/runtime/lib/libmindspore-lite.a --configFile=./cropper_mapping_cpu.cfg --modelFile=/model/lenet.ms,/model/retinaface.ms  --outputFile=/mindspore-lite/lib/libmindspore-lite.a

In this example, the libmindspore-lite.a static library of arm64-cpu will be cropped according to the ms model passed by modelFile, and the cropped libmindspore-lite.a static library will be saved to /mindspore-lite/lib/ directory.

Pass in the ms model through the folder, and pass the folder path where the model file is located to the modelFolderPath parameter to crop the libmindspore-lite.a static library of arm64-gpu.

./cropper --packageFile=/mindspore-lite-{version}-android-aarch64/runtime/lib/libmindspore-lite.a --configFile=./cropper_mapping_gpu.cfg --modelFolderPath=/model --outputFile=/mindspore-lite/lib/libmindspore-lite.a

This example will read all the ms models contained in the /model folder, crop the libmindspore-lite.a static library of arm64-gpu, and the cropped libmindspore-lite.a static library will be saved to /mindspore-lite/lib/ directory.

Pass in the ms model by file, pass the path where the model file is located to the modelFile parameter, and crop the libmindspore-lite.a static library of arm64-gpu.

./cropper --packageFile=/mindspore-lite-{version}-android-aarch64/runtime/lib/libmindspore-lite.a --configFile=./cropper_mapping_gpu.cfg --modelFile=/model/lenet.ms,/model/retinaface.ms  --outputFile=/mindspore-lite/lib/libmindspore-lite.a

In this example, the libmindspore-lite.a static library of arm64-gpu will be cropped according to the ms model passed by modelFile, and the cropped libmindspore-lite.a static library will be saved to /mindspore-lite/lib/ directory.

Compiling Static Library Into Dynamic Library (Optional)

After cropping the static library, if necessary, the cropped static library can be compiled into a dynamic library. The compilation environment requirements refer to the compilation requirements of MindSpore Lite . The compilation commands used for packages under different architectures are different. The specific commands can be obtained through the commands printed during the compilation of MindSpore Lite . Refer to the example steps below.

Add the following command to lite/Cmakelist.txt to enable the compilation process to print.
```
set(CMAKE_VERBOSE_MAKEFILE on)
```
Refer to the MindSpore Lite compilation to compile the runtime package on the specific architecture required.

After the compilation is completed, find the command for compiling libminspore-lite.so in the printed compilation information. The following is the print command when compiling the runtime package of arm64 architecture, where /home/android-ndk-r20b is the path of the installed Android SDK.

/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=aarch64-none-linux-android21 --gcc-toolchain=/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64 --sysroot=/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64/sysroot -fPIC -D_FORTIFY_SOURCE=2 -O2 -Wall -Werror -Wno-attributes -Wno-deprecated-declarations         -Wno-missing-braces -Wno-overloaded-virtual -std=c++17 -fPIC -fPIE -fstack-protector-strong  -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -fno-addrsig -Wa,--noexecstack -Wformat -Werror=format-security    -fomit-frame-pointer -fstrict-aliasing -ffunction-sections         -fdata-sections -ffast-math -fno-rtti -fno-exceptions -Wno-unused-private-field -O2 -DNDEBUG  -Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack -s  -Wl,--exclude-libs,libgcc.a -Wl,--exclude-libs,libatomic.a -static-libstdc++ -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Qunused-arguments -Wl,-z,noexecstack  -shared -Wl,-soname,libmindspore-lite.so -o libmindspore-lite.so @CMakeFiles/mindspore-lite.dir/objects1.rsp  -llog -ldl -latomic -lm

Modify the command, replace the object to be compiled, and compile the cropped static library into a dynamic library.

Take the above print command as an example to find the object @CMakeFiles/mindspore-lite.dir/objects1.rsp to be compiled in the command, replace with the cropped static library object -Wl,--whole-archive ./libmindspore-lite.a -Wl,--no-whole-archive, Where ./libmindspore-lite.a is the cropped static library path. You can replace it with the path of your own library. The modified command is as follows.

/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64/bin/clang++ --target=aarch64-none-linux-android21 --gcc-toolchain=/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64 --sysroot=/home/android-ndk-r20b/toolchains/llvm/prebuilt/linux-x86_64/sysroot -fPIC -D_FORTIFY_SOURCE=2 -O2 -Wall -Werror -Wno-attributes -Wno-deprecated-declarations         -Wno-missing-braces -Wno-overloaded-virtual -std=c++17 -fPIC -fPIE -fstack-protector-strong  -DANDROID -fdata-sections -ffunction-sections -funwind-tables -fstack-protector-strong -no-canonical-prefixes -fno-addrsig -Wa,--noexecstack -Wformat -Werror=format-security    -fomit-frame-pointer -fstrict-aliasing -ffunction-sections         -fdata-sections -ffast-math -fno-rtti -fno-exceptions -Wno-unused-private-field -O2 -DNDEBUG  -Wl,-z,relro -Wl,-z,now -Wl,-z,noexecstack -s  -Wl,--exclude-libs,libgcc.a -Wl,--exclude-libs,libatomic.a -static-libstdc++ -Wl,--build-id -Wl,--warn-shared-textrel -Wl,--fatal-warnings -Wl,--no-undefined -Qunused-arguments -Wl,-z,noexecstack  -shared -Wl,-soname,libmindspore-lite.so -o libmindspore-lite.so -Wl,--whole-archive ./libmindspore-lite.a -Wl,--no-whole-archive  -llog -ldl -latomic -lm

Use this command to compile the clipped static library into a dynamic library and generate ‘libminspore-lite.so’ in the current directory.

In the command example, -static-libstdc++ indicates the integration of static STD library. You can delete the command and link the dynamic STD library instead to reduce the package size.