[SOLVED] testing in a while loop (MARIE)

testing in a while loop (MARIE)

I'm trying to write a while loop, while N > 5.

While I understand just making a loop point and jumping back to it, how should I write a skipcond test for N > 5?

I looked at the one other MARIE question regarding while loops, but didn't quite get an answer out of it.

EDIT: Forgot to mention my idea was to subtract 5 from N, then skipcond 800 to see if it is true or not. Is this a proper way of doing it?

Solution

Here is what a while loop close to yours looks like in MARIE.

Regarding your question, subtracting 5 from N after you write Loop, Load N, should work just fine.

 X := 1;
 while X < 10 do
     X := X + 1;
 endwhile;

----- Marie Code of above

ORG 100
         Load One
         Store X      /Initialize X
Loop,    Load X       /Load loop constant
         Subt Ten     /Compare X to 10
         SkipCond 000 /If AC<0 (X is less than 10), continue loop
         Jump Endloop /If X is not less than 10, terminate loop
         Load X       /Begin body of loop
         Add One      /Add 1 to X
         Store X      /Store new value in X
         Jump Loop    /Continue loop
Endloop, Halt         /Terminate program
X,       Dec 0        /Storage for X
One,     Dec 1        /The constant value 1
Ten,     Dec 10       /The loop constant