From 5b6637fb92c54b8f367ec8751f53f6f238d8dbed Mon Sep 17 00:00:00 2001
From: Jan Tuomi <jans.tuomi@gmail.com>
Date: Sun, 9 Apr 2023 18:26:25 +0300
Subject: Remake ALU

---
 src/test_fibo.atk16 | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 src/test_fibo.atk16

(limited to 'src/test_fibo.atk16')

diff --git a/src/test_fibo.atk16 b/src/test_fibo.atk16
new file mode 100644
index 0000000..7f1abb9
--- /dev/null
+++ b/src/test_fibo.atk16
@@ -0,0 +1,47 @@
+@opt stack_pointer RG
+
+@label program
+  ; call fibo subroutine with parameter 10
+  ldi RA 10
+  csr fibo
+  hlt
+
+@label fibo
+  ; function fibo
+  ; parameters:
+  ;  RA   n : u16
+  ; return value:
+  ;  RA   fibo(n) : u16
+
+  spu RB                ; prelude
+  spu RC
+
+  ldi RC 2              ; if n < 2, return n
+  sub RA RC RA
+  bri f_sign fibo_early
+
+  spu RD                 ; prelude
+  spu RE
+
+  ldi RE 1               ; constant 1
+  ldi RB 0               ; a = 0
+  ldi RC 1               ; b = 1
+@label fibo_loop
+  add RB RC RD           ; v = a + b
+  mov RC RB              ; a = b
+  mov RD RC              ; b = v
+  sub RA RE RA           ; n -= 1
+  bri f_zero fibo_done   ; loop while n > 0
+  jpi fibo_loop
+
+@label fibo_early
+  spo RC
+  spo RB
+  rsr
+@label fibo_done
+  ldr RD RA
+  spo RE
+  spo RD
+  spo RC
+  spo RB
+  rsr
-- 
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