Leveraging property access optimization in the V8 JavaScript engine for improved runtime performance

Abstract: The ability of JavaScript-objects to alter memory layout during runtime requires the V8  JavaScript engine to perform a search operation everytime an object property is accessed. To improve performance, the V8 JavaScript engine attempts to optimize object property accesses upon JIT-compilation. The efficacy of these access optimizations depends on the application JavaScript source code. We analyzed the effect of poorly optimized property accesses and mitigation strategies using compiler analysis tools, benchmarking and literature studies. We found that property access is around four times slower when poorly optimized. In addition, we reduced the total execution time of an Octane 2.0 benchmark application with 25% by detecting poorly optimized property accesses and making a few changes in the application source code that helps the V8 JavaScript engine to better optimize these property accesses.