fix bugs in pointer decompilation

ICSharpCode.Decompiler/CSharp/ExpressionBuilder.cs

@@ -349,7 +349,24 @@ namespace ICSharpCode.Decompiler.CSharp
 			var resolverWithOverflowCheck = resolver.WithCheckForOverflow(inst.CheckForOverflow);
 			var left = Translate(inst.Left);
 			var right = Translate(inst.Right);
-			var rr = resolverWithOverflowCheck.ResolveBinaryOperator(op, left.ResolveResult, right.ResolveResult);
+			ResolveResult rr;
+			if (left.Type.IsKnownType(KnownTypeCode.IntPtr) || left.Type.IsKnownType(KnownTypeCode.UIntPtr)
+			    || right.Type.IsKnownType(KnownTypeCode.IntPtr) || right.Type.IsKnownType(KnownTypeCode.UIntPtr)) {
+				IType targetType;
+				if (inst.Sign == Sign.Unsigned) {
+					targetType = compilation.FindType(KnownTypeCode.UInt64);
+				} else {
+					targetType = compilation.FindType(KnownTypeCode.Int64);
+				}
+				left = left.ConvertTo(targetType, this);
+				right = right.ConvertTo(targetType, this);
+				rr = new OperatorResolveResult(targetType, BinaryOperatorExpression.GetLinqNodeType(op, inst.CheckForOverflow), left.ResolveResult, right.ResolveResult);
+				var resultExpr = new BinaryOperatorExpression(left.Expression, op, right.Expression)
+					.WithILInstruction(inst)
+					.WithRR(rr);
+				return resultExpr.ConvertTo(compilation.FindType(inst.ResultType.ToKnownTypeCode()), this);
+			} else {
+				rr = resolverWithOverflowCheck.ResolveBinaryOperator(op, left.ResolveResult, right.ResolveResult);
 				if (rr.IsError || rr.Type.GetStackType() != inst.ResultType
 				    || !IsCompatibleWithSign(left.Type, inst.Sign) || !IsCompatibleWithSign(right.Type, inst.Sign))
 				{
@@ -363,6 +380,7 @@ namespace ICSharpCode.Decompiler.CSharp
 					.WithILInstruction(inst)
 					.WithRR(rr);
 			}
+		}
 
 		/// <summary>
 		/// Gets whether <paramref name="type"/> has the specified <paramref name="sign"/>.

ICSharpCode.Decompiler/IL/ILReader.cs

@@ -878,10 +878,22 @@ namespace ICSharpCode.Decompiler.IL
 			int target = shortForm ? reader.ReadSByte() : reader.ReadInt32();
 			target += reader.Position;
 			ILInstruction condition = Pop();
-			if (condition.ResultType == StackType.O) {
+			switch (condition.ResultType) {
+				case StackType.O:
 					// introduce explicit comparison with null
 					condition = new Ceq(condition, new LdNull());
 					negate = !negate;
+					break;
+				case StackType.I:
+					// introduce explicit comparison with 0
+					condition = new Ceq(condition, new LdcI4(0));
+					negate = !negate;
+					break;
+				case StackType.I8:
+					// introduce explicit comparison with 0
+					condition = new Ceq(condition, new LdcI8(0));
+					negate = !negate;
+					break;
 			}
 			if (negate) {
 				condition = new LogicNot(condition);