From ab03580e88adf3f4dec4201994d1dd1cd344f9b7 Mon Sep 17 00:00:00 2001
From: kudzu_cp <6d05c8c8ef5431987001abfdb2eadc9593ac9498>
Date: Mon, 23 Aug 2010 15:50:42 +0000
Subject: [PATCH] Fix for loading of sbyte in ldc

---
 source2/IL2PCU/Cosmos.IL2CPU/ILReader.cs | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/source2/IL2PCU/Cosmos.IL2CPU/ILReader.cs b/source2/IL2PCU/Cosmos.IL2CPU/ILReader.cs
index c475c998f..51eff05d8 100644
--- a/source2/IL2PCU/Cosmos.IL2CPU/ILReader.cs
+++ b/source2/IL2PCU/Cosmos.IL2CPU/ILReader.cs
@@ -289,7 +289,15 @@ namespace Cosmos.IL2CPU {
           case OperandType.ShortInlineI:
             switch (xOpCodeVal) {
               case ILOpCode.Code.Ldc_I4_S:
-                    xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);
+                    // x = x & 0xFFFFFFFC;
+                    // The above code produces:
+                    // ldc.i4.s -4
+                    // But its getting loaded into a I4, so we have to "extend" it
+                    //
+                    // First we have to cast it to a signed byte, so .NET will extend it properly to a uint.
+                    sbyte xSVal = (sbyte)xIL[xPos];
+                    uint xVal = (uint)xSVal;
+                    xILOpCode = new ILOpCodes.OpInt(ILOpCode.Code.Ldc_I4, xOpPos, xPos + 1, xVal, xCurrentHandler);
                 break;
               default:
                 xILOpCode = new ILOpCodes.OpInt(xOpCodeVal, xOpPos, xPos + 1, xIL[xPos], xCurrentHandler);