Worked on AVX type casting enhancements in the emscripten-core/emscripten repository, focusing on improving interoperability between AVX and legacy SIMD code. Leveraging C programming and AVX intrinsics, the developer redefined __m256* as vector types using __vector_size, enabling seamless casting among AVX types. The approach preserved existing AVX function implementations by introducing internal per-lane conversions, allowing calls to route through legacy m128 paths without disrupting current workflows. This work addressed cross-compatibility issues, reduced integration friction for SIMD workloads, and laid the foundation for improved maintainability and potential performance gains in the WebAssembly toolchain’s SIMD-related code paths.