source2/IL2PCU/Cosmos.IL2CPU.X86/Cosmos.IL2CPU.X86.csproj

@@ -347,6 +347,7 @@
     <Compile Include="X86\Registers.cs" />
     <Compile Include="X86\Return.cs" />
     <Compile Include="X86\RotateThroughCarryRight.cs" />
+    <Compile Include="X86\Scas.cs" />
     <Compile Include="X86\SetInterruptFlag.cs" />
     <Compile Include="X86\ShiftLeft.cs" />
     <Compile Include="X86\ShiftRight.cs" />

source2/IL2PCU/Cosmos.IL2CPU.X86/X86/Scas.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace Cosmos.IL2CPU.X86
+{
+    [OpCode("scas")]
+    public class Scas: InstructionWithSize, IInstructionWithPrefix
+    {
+        public static void InitializeEncodingData(Instruction.InstructionData aData)
+        {
+        }
+
+        public InstructionPrefixes Prefixes
+        {
+            get;
+            set;
+        }
+
+        public override void WriteText(Cosmos.IL2CPU.Assembler aAssembler, System.IO.TextWriter aOutput)
+        {
+            if ((Prefixes & InstructionPrefixes.RepeatTillNotEqual) != 0)
+            {
+                aOutput.Write("repne ");
+            }
+            switch (Size)
+            {
+                case 32:
+                    aOutput.Write("scasd");
+                    return;
+                case 16:
+                    aOutput.Write("scasw");
+                    return;
+                case 8:
+                    aOutput.Write("scasb");
+                    return;
+                default: throw new Exception("Size not supported!");
+            }
+        }
+    }
+}

source2/IL2PCU/Cosmos.IL2CPU.X86/X86/_Infra/IInstructionWithPrefix.cs

@@ -9,7 +9,7 @@ namespace Cosmos.IL2CPU.X86 {
         None,
         Lock,
         Repeat,
-        RepeatNotEqual
+        RepeatTillNotEqual
     }
 
     public interface IInstructionWithPrefix {