From 6e90d1e433811ceca4bf37473ac1c76770afdf7c Mon Sep 17 00:00:00 2001
From: Lioncash <mathew1800@gmail.com>
Date: Thu, 9 Jul 2015 13:08:37 -0400
Subject: [PATCH] SI_DeviceGCController: Remedy undefined behavior regarding
 shifts

Left shifting a negative left-hand operand is undefined behavior per section 5.8.2 of the C++11 standard.
---
 Source/Core/Core/HW/SI_DeviceGCController.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Source/Core/Core/HW/SI_DeviceGCController.h b/Source/Core/Core/HW/SI_DeviceGCController.h
index f738ad16fd..1a341051e4 100644
--- a/Source/Core/Core/HW/SI_DeviceGCController.h
+++ b/Source/Core/Core/HW/SI_DeviceGCController.h
@@ -118,7 +118,11 @@ public:
 	virtual bool GetData(u32& _Hi, u32& _Low) override
 	{
 		CSIDevice_GCController::GetData(_Hi, _Low);
-		_Hi &= ~PAD_USE_ORIGIN << 16;
+
+		// Unset all bits except those that represent
+		// A, B, X, Y, Start and the error bits, as they
+		// are not used.
+		_Hi &= ~0x20FFFFFF;
 		return true;
 	}
 };