2.9BSD - /usr/src/lib/c/nonfpcrt/almul.s

   1: /
   2: / 32-bit multiplication routine for fixed pt hardware.
   3: /  Implements *= operator
   4: / Credit to an unknown author who slipped it under the door.
   5: .globl  almul
   6: .globl  csv, cret
   7: 
   8: almul:
   9:         jsr     r5,csv
  10:         mov     4(r5),r4
  11:         mov     2(r4),r2
  12:         sxt     r1
  13:         sub     (r4),r1
  14:         mov     8.(r5),r0
  15:         sxt     r3
  16:         sub     6.(r5),r3
  17:         mul     r0,r1
  18:         mul     r2,r3
  19:         add     r1,r3
  20:         mul     r2,r0
  21:         sub     r3,r0
  22:         mov     r0,(r4)+
  23:         mov     r1,(r4)
  24:         jmp     cret

Defined functions