94.574 Elements of Computer Systems

SCE 574

Returning from a Jump

äWhat do we do? How do we branch back to another part of our code?

äCan hard code a finite state machine into our assembly language program

äBut what if we want to branch back to where we came from, and we can come from many places?

äCould store a return address in a chosen register, branch to its address at the end of the call

äThis would be a calling convention

äMore general support is available from subroutine CALL and RET operations

A: goto B

B: If X >0

goto C

Else Goto D

C: goto A

D: goto B