Worked on the espressif/llvm-project repository to address a compile-time regression affecting performance and stability. Focused on optimizing the SSAUpdater component by implementing an instruction order optimization that leverages existing instruction ordering numbers, thereby eliminating the need to scan basic blocks during evaluation. This approach reduced unnecessary computation and improved compile-time efficiency, leading to more predictable CI and build times. The work involved code refactoring and performance tuning using C++, with an emphasis on compiler optimization techniques. By resolving a key bug, the developer contributed to smoother development workflows and enhanced productivity for teams relying on the espressif/llvm-project.