- mov %rsp,%rbx # The current sp marks start of new frame.
- push %rbp # fp in save location S0
- sub $16,%rsp # Ensure 3 slots are allocated, one above.
- mov %rbx,%rbp # Switch to new frame.
+ push %rbp # Dummy for return address
+ push %rbp # fp in save location S1
+ mov %rsp,%rbp # The current sp marks start of new frame.
+ sub $8,%rsp # Ensure 3 slots are allocated, two above.