Worked on the rust-lang/gcc repository to address a critical alignment issue in the SH architecture’s libgcc when using the -mrelax option. Focused on low-level programming and compiler development, the work involved aligning the ashiftrt_r4_32 instruction and enforcing mova alignment within movemem to ensure correct instruction positioning. This fix, implemented in Assembly, targeted regressions that previously caused build failures, thereby improving toolchain reliability for embedded systems. The patch was prepared, reviewed, and validated with targeted SH builds, contributing upstream to enhance build stability and reduce potential release blockers for -mrelax-enabled configurations in the SH architecture toolchain.