1 files changed, 41 insertions, 0 deletions
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