Worked on performance-oriented backend development in the rust-lang/gcc repository, focusing on optimizing AArch64 SIMD instruction sequences for improved loop performance on 64-bit ARM architectures. Developed an enhancement that replaced the mvn+shrn sequence with mvni+subhn, leveraging assembly language and compiler optimization expertise to streamline critical code paths. Integrated automated tests in C to ensure the correctness and regression safety of the new optimization, supporting robust and maintainable code. Demonstrated a strong understanding of SIMD instructions and low-level performance tuning, contributing to the repository’s goals of efficient execution and reliable backend behavior for performance-critical workloads on ARM platforms.