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        riddles >> cs >> How to divide with SIC sbn instruction
        
(Message started by: MOR on Mar 25^th, 2013, 2:26am)

Title: How to divide with SIC sbn instruction
Post by MOR on Mar 25^th, 2013, 2:26am

Hello there,

I want to implement the C code

Code:

c = a div b;

on SIC with sbn instruction.
Any help with this?

The command does the following:

sbn a,b,c # Mem[a] = Mem[a] – Mem[b];if (Mem[a]<0) go to c

I am looking forward to hearing from you and i would appreciate any kind of help. thank you.

Title: Re: How to divide with SIC sbn instruction
Post by akasina9 on Apr 2^nd, 2013, 9:29pm

You can look at division as a subtraction loop. The following code block assumes that the initial instruction starts at address n:

Code:

sbn u, u # Initialize u to 0
sbn c, c # Initialize c to 0
sbn u, ONE # Initialize u to -1
sbn a, b, n+6 # Subtract b from a until it is less than zero
sbn c, u # increment c by one each time a is positive
sbn ZERO, ONE, n+3 # Unconditional jump to the subtraction step
exit