1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
.global ___smulhi3 ___smulhi3: lda #0 mult1: ldx <r4 beq done lsr <r4 bcc mult2 clc adc <r5 mult2: asl <r5 bra mult1 done: sta <r0 rtl