1b and 1f in GNU assembly

Question

I am analyzing a linux exception code. By the way I can\'t understand gnu assembly syntax.

    svc_preempt:
    mov r8, lr
1:  bl  preempt_schedule_irq               


        

Answer 1

These are relative branches (so many bytes forwards or backwards relative to the current position) so they don't really have a label. However, when visualizing code it is easier to actually have some kind of visualization of where it goes to - hence the "not-label" of 1 and the backwards and forwards jumps.

I had to work with the alternative on the IBM370 mainframe - believe me, that's not fun!