/// <summary>
/// Evaluates the given 32-bit operation and parameters to evaluate the status of the Overflow Flag
/// </summary>
/// <param name="arithmeticOperation"></param>
/// <param name="result"></param>
/// <param name="destination"></param>
/// <param name="source"></param>
public void EvaluateOverflow(EnumArithmeticOperation arithmeticOperation, uint result = 0,
uint destination = 0, uint source = 0)
{
var setFlag = false;
switch (arithmeticOperation)
{
case EnumArithmeticOperation.Addition:
{
//positive+positive==negative
if (!destination.IsNegative() && !source.IsNegative() &&
result.IsNegative())
{
setFlag = true;
}
//negative+negative==positive
if (destination.IsNegative() && source.IsNegative() &&
!result.IsNegative())
{
setFlag = true;
}
break;
}
case EnumArithmeticOperation.Subtraction:
{
// negative-positive==positive
if (destination.IsNegative() && !source.IsNegative() &&
!result.IsNegative())
{
setFlag = true;
}
// positive-negative==negative
if (!destination.IsNegative() && source.IsNegative() &&
result.IsNegative())
{
setFlag = true;
}
break;
}
default:
throw new ArgumentOutOfRangeException(nameof(arithmeticOperation), arithmeticOperation,
"Unsupported Carry Flag Operation for Evaluation");
}
if (setFlag)
{
SetFlag(EnumFlags.OF);
}
else
{
ClearFlag(EnumFlags.OF);
}
}
/// <summary>
/// Evaluates the given 32-bit operation and parameters to evaluate the status of the Carry Flag
/// </summary>
/// <param name="arithmeticOperation"></param>
/// <param name="result"></param>
/// <param name="destination"></param>
/// <param name="source"></param>
public void EvaluateCarry(EnumArithmeticOperation arithmeticOperation, uint result = 0,
uint destination = 0, uint source = 0)
{
bool setFlag = arithmeticOperation switch
{
EnumArithmeticOperation.Addition => ((ulong)source + destination) > uint.MaxValue,
EnumArithmeticOperation.Subtraction => result > destination,
EnumArithmeticOperation.ShiftLeft => !result.IsNegative() && destination.IsNegative(),
_ => throw new ArgumentOutOfRangeException(nameof(arithmeticOperation), arithmeticOperation,
"Unsupported Carry Flag Operation for Evaluation")
};
if (setFlag)
{
SetFlag(EnumFlags.CF);
}
else
{
ClearFlag(EnumFlags.CF);
}
}