Hi there, We know that GCC has options that control optimization. What I tried to do was to align functions with the -falign-functions option. However I noticed that this option only controls the user code, without affecting the library instructions. Although finally I modified linker script to fulfill my goal. I still want to know how gcc handles the alignment options? I guess it does so by passing some option to ld.. But why doesn't the option affect the libraries? Thank you very much.