From 9220a2a66c883e75117d01eb80bfa7bbf6f221e4 Mon Sep 17 00:00:00 2001
From: Isaac <i.hall@cityoflondonschool.org.uk>
Date: Sat, 25 Mar 2023 20:16:58 +0000
Subject: [PATCH] Unrolled loop

Does two iterations per loop, so doesn't need 3rd register for swapping
---
 programs/fib.as | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/programs/fib.as b/programs/fib.as
index acbecfc..bf0cc7d 100644
--- a/programs/fib.as
+++ b/programs/fib.as
@@ -6,15 +6,16 @@ define iterations 13
 
       ldi r1 #0
       ldi r2 #1
-      ldi r3 #0
       ldi r4 iterations
       ldi r7 number_display
 .loop str r3
       cmp r4 r0
       bif zero .done
-      cpy r1 r2
-      cpy r2 r3
-      add r3 r1 r2
+      add r1 r1 r2
+      add r2 r1 r2
+      dec r4 r4
+      cmp r4 r0
+      bif zero .done
       dec r4 r4
       jmp .loop
 .done hlt