2.9BSD - /usr/src/lib/c/sys/mpxcall.s

   1: .globl _mpxcall, cerror
   2: 
   3: _mpxcall:
   4:         mov     r5,-(sp)
   5:         mov     sp,r5
   6:         mov     4(r5),0f
   7:         mov     6(r5),0f+2
   8: call:
   9:         sys     0; 9f
  10:         bec     1f
  11:         jmp     cerror
  12: 1:
  13:         mov     (sp)+,r5
  14:         rts     pc
  15: .data
  16: 9:
  17:         sys     mpx; 0:..; ..

Defined functions