also does codegen-units = 1 really help in our case? Setting it to 1 doesn't guarantee better optimization, therefore just asking haha

@swanandx From official documentation:

This flag controls how many code generation units the crate is split into. It takes an integer greater than 0.

When a crate is split into multiple codegen units, LLVM is able to process them in parallel. Increasing parallelism ?may speed up compile times, but may also produce slower code. Setting this to 1 may improve the performance of generated code, but may be slower to compile.