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-rw-r--r--home/compare.asm35
1 files changed, 35 insertions, 0 deletions
diff --git a/home/compare.asm b/home/compare.asm
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index 000000000..26b7567fd
--- /dev/null
+++ b/home/compare.asm
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+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