From fb13d9fdcecc92d3603c7d8ed556910bf93fcd65 Mon Sep 17 00:00:00 2001
From: "Adrian.Conlon" <adrian.conlon@gmail.com>
Date: Sun, 13 Aug 2017 21:34:19 +0100
Subject: [PATCH] Correct GB: SWAP r operation. The demoted high nibble was
 being effectively zeroed each time.

Signed-off-by: Adrian.Conlon <adrian.conlon@gmail.com>
---
 LR35902/src/LR35902.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/LR35902/src/LR35902.cpp b/LR35902/src/LR35902.cpp
index f0a8761..4e28c16 100644
--- a/LR35902/src/LR35902.cpp
+++ b/LR35902/src/LR35902.cpp
@@ -342,7 +342,7 @@ void EightBit::LR35902::ccf(uint8_t& a, uint8_t& f) {
 uint8_t EightBit::LR35902::swap(uint8_t& f, uint8_t operand) {
 	auto low = lowNibble(operand);
 	auto high = highNibble(operand);
-	operand = promoteNibble(low) | demoteNibble(high);
+	operand = promoteNibble(low) | high;
 	adjustZero<LR35902>(f, operand);
 	clearFlag(f, NF | HC | CF);
 	return operand;