;---------------------------------------------------------------------------
; 16x16 => 32 unsigned multiplication routine.
;
-; lhs rhs result result also in
-; -------------------------------------------------------------
-; ptr1 ax ax:sreg ptr1:sreg
+; routine lhs rhs result result also in
+; -----------------------------------------------------------------------
+; umul16x16r32 ptr1 ax ax:sreg ptr1:sreg
+; umul16x16r32m ptr1 ptr3 ax:sreg ptr1:sreg
+;
+; ptr3 is left intact by the routine.
;
umul16x16r32: