From 091c684bf1d2cca09da001b9170b205dbe5c333f Mon Sep 17 00:00:00 2001
From: Freya Murphy <freya@freyacat.org>
Date: Tue, 1 Oct 2024 18:22:10 -0400
Subject: add recursion test, add noops for branch delay slots

---
 test/masm/recursion.asm | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 test/masm/recursion.asm

(limited to 'test/masm/recursion.asm')

diff --git a/test/masm/recursion.asm b/test/masm/recursion.asm
new file mode 100644
index 0000000..38982e1
--- /dev/null
+++ b/test/masm/recursion.asm
@@ -0,0 +1,41 @@
+# Copyright (c) 2024 Freya Murphy
+
+# file: recursion.asm
+# test: should recurse sum n..0 numbers
+
+.text
+.align 2
+.globl main
+
+main:
+	# init $a0
+	li	$a0, 5
+
+sum:
+	# save stack
+	addiu	$sp, $sp, -8
+	sw	$ra, 0($sp)
+	sw	$s0, 4($sp)
+
+	# load n from a0
+	move	$s0, $a0
+
+	# skip if n is zero
+	li	$v0, 0
+	beq	$s0, $zero, add
+	nop
+	jal	sum
+	addi	$a0, $s0, -1
+
+add:
+	# n = n + returned
+	add	$v0, $s0, $v0
+
+	# restore stack
+	lw	$ra, 0($sp)
+	lw	$s0, 4($sp)
+	addiu	$sp, $sp, 8
+
+	# return
+	jr	$ra
+	nop
-- 
cgit v1.2.3-freya