Add home/compare.asm

1 files changed, 35 insertions, 0 deletions

diff --git a/home/compare.asm b/home/compare.asm
new file mode 100755
index 00000000..bd665ef4
--- /dev/null
+++ b/home/compare.asm
@@ -0,0 +1,35 @@
+CompareBytes::
+; Compare c bytes at de and hl.
+; Return z if they all match.
+.loop
+	ld a, [de]
+	cp [hl]
+	ret nz
+	inc de
+	inc hl
+	dec c
+	jr nz, .loop
+	ret
+
+CompareBytesLong::
+; Compare bc bytes at de and hl.
+; Return carry if they all match.
+.loop
+	ld a, [de]
+	cp [hl]
+	jr nz, .diff
+
+	inc de
+	inc hl
+	dec bc
+
+	ld a, b
+	or c
+	jr nz, .loop
+
+	scf
+	ret
+
+.diff:
+	and a
+	ret
\ No newline at end of file