2.9BSD - /usr/src/lib/c/crt/mcount.s

   1: / count subroutine calls during profiling
   2: 
   3: .globl  mcount
   4: .comm   countbase,2
   5: 
   6: mcount:
   7:         mov     (r0),r1
   8:         bne     1f
   9:         mov     countbase,r1
  10:         beq     2f
  11:         add     $6,countbase
  12:         mov     (sp),(r1)+
  13:         mov     r1,(r0)
  14: 1:
  15:         inc     2(r1)
  16:         bne     2f
  17:         inc     (r1)
  18: 2:
  19:         rts     pc

Defined functions

Defined variables