This repository contains a reference implementation of Similar Function Elimination, a post build optimization pass for the Emscripten transpiler that coalesces functions that share similar structure but different literals or identifiers into helper functions. It maintains asm.js compliance as well.
Can be found here.
- The ability to run (a hopefully recent version of) Emscripten. This has been tested with version 1.37.16.
- Some flavor of Linux (might work on Windows and OSX but not tested on those platforms). This has been tested on CentOS 7.
- A version of NodeJS that understands ES6. Tested with version 8.4.0.
- There are a number of tests for SFE located under tests/unit_tests/
- To run them, first set up your environment from the root directory of your repository.
source ./bin/sfe_env.sh - Then run:
mocha ./tests/unit_tests/*.js
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Clone the repository and check out the master branch
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Navigate to the examples directory. Make sure that you can run emcc from your command line.
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Run the following command: sh ./run.sh
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This will run Emscripten on the printContainers.cpp example code, followed by a subsequent execution of SFE. In our testing, we see the following results.
-rw-r--r-- 1 achoudhury domain users 627268 Aug 17 16:46 printContainer.js
-rw-r--r-- 1 achoudhury domain users 505126 Aug 17 16:46 printContainer_reduced.js
SFE works quite well on template heavy codebases. On our simple example where we were printing the contents of a number of STL containers, we see a 20% size reduction with SFE. Your mileage may vary depending on how template heavy your codebase is.