Speeding Up CRuby's FFI with JIT Compilation

This article explores using Just-In-Time (JIT) compilation to improve the performance of Ruby's Foreign Function Interface (FFI). Benchmarks demonstrate FFI's performance drawbacks compared to native extensions. The author introduces FJIT, a solution leveraging RJIT and custom machine code generation to create runtime machine code for calling external functions, bypassing FFI overhead. FJIT outperforms native extensions in tests, offering a high-performance alternative for Ruby developers. Currently a prototype supporting only ARM64, FJIT's future expansion to other architectures and more complex function calls is anticipated.