private static Value Modulo(ISnapshotReadWrite snapshot, IntervalValue <int> leftOperand,
int rightOperand)
{
IntervalValue <int> result;
if (leftOperand.Start >= 0)
{
result = PositiveDividendModulo(snapshot, leftOperand.Start,
leftOperand.End, rightOperand);
}
else
{
if (leftOperand.End <= 0)
{
result = NegativeDividendModulo(snapshot, leftOperand.Start,
leftOperand.End, rightOperand);
}
else
{
var negative = NegativeDividendModulo(snapshot, leftOperand.Start, 0, rightOperand);
var positive = PositiveDividendModulo(snapshot, 0, leftOperand.End, rightOperand);
result = snapshot.CreateIntegerInterval(negative.Start, positive.End);
}
}
if (result.Start < result.End)
{
return(result);
}
else
{
return(snapshot.CreateInt(result.Start));
}
}
/// <summary>
/// Perform bitwise operation for given integer operands.
/// </summary>
/// <param name="snapshot">Read-write memory snapshot used for fix-point analysis.</param>
/// <param name="operation">Operation to be performed, only the bitwise one gives a result.</param>
/// <param name="leftOperand">Left integer operand of bitwise operation.</param>
/// <param name="rightOperand">Right integer operand of bitwise operation.</param>
/// <returns>If operation is bitwise, it returns integer result, otherwise <c>null</c>.</returns>
public static IntegerValue Bitwise(ISnapshotReadWrite snapshot, Operations operation,
int leftOperand, int rightOperand)
{
switch (operation)
{
case Operations.BitAnd:
return(snapshot.CreateInt(leftOperand & rightOperand));
case Operations.BitOr:
return(snapshot.CreateInt(leftOperand | rightOperand));
case Operations.BitXor:
return(snapshot.CreateInt(leftOperand ^ rightOperand));
case Operations.ShiftLeft:
return(snapshot.CreateInt(leftOperand << rightOperand));
case Operations.ShiftRight:
return(snapshot.CreateInt(leftOperand >> rightOperand));
default:
return(null);
}
}