public void XorBitwiseByte(IRegisters registers, IALU.TargetRegister targetRegister, byte value)
{
byte result;
switch (targetRegister)
{
case IALU.TargetRegister.A:
result = registers.A;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.B:
result = registers.B;
break;
case IALU.TargetRegister.C:
result = registers.C;
break;
case IALU.TargetRegister.D:
result = registers.D;
break;
case IALU.TargetRegister.E:
result = registers.E;
break;
case IALU.TargetRegister.H:
result = registers.H;
break;
case IALU.TargetRegister.L:
result = registers.L;
break;
default:
throw new ArgumentException();
}
result ^= value;
if (result == 0)
{
registers.ZeroFlag = true;
}
registers.NegativeFlag = false;
registers.HalfCarryFlag = false;
registers.FullCarryFlag = false;
switch (targetRegister)
{
case IALU.TargetRegister.A:
registers.A = result;
break;
case IALU.TargetRegister.F:
registers.F = result;
break;
case IALU.TargetRegister.B:
registers.B = result;
break;
case IALU.TargetRegister.C:
registers.C = result;
break;
case IALU.TargetRegister.D:
registers.D = result;
break;
case IALU.TargetRegister.E:
registers.E = result;
break;
case IALU.TargetRegister.H:
registers.H = result;
break;
case IALU.TargetRegister.L:
registers.L = result;
break;
}
}
public void DecrementRegister(IRegisters registers, IALU.TargetRegister targetRegister)
{
int result;
bool is16Bit = false;
switch (targetRegister)
{
case IALU.TargetRegister.A:
result = registers.A;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.AF:
is16Bit = true;
result = registers.AF;
break;
case IALU.TargetRegister.B:
result = registers.B;
break;
case IALU.TargetRegister.C:
result = registers.C;
break;
case IALU.TargetRegister.BC:
is16Bit = true;
result = registers.BC;
break;
case IALU.TargetRegister.D:
result = registers.D;
break;
case IALU.TargetRegister.E:
result = registers.E;
break;
case IALU.TargetRegister.DE:
is16Bit = true;
result = registers.DE;
break;
case IALU.TargetRegister.H:
result = registers.H;
break;
case IALU.TargetRegister.L:
result = registers.L;
break;
case IALU.TargetRegister.HL:
is16Bit = true;
result = registers.HL;
break;
case IALU.TargetRegister.SP:
is16Bit = true;
result = registers.SP;
break;
default:
throw new ArgumentException();
}
int originalValue = result;
result -= 1;
if (!is16Bit)
{
registers.NegativeFlag = true;
if ((result & 0xFF) == 0)
{
registers.ZeroFlag = true;
}
if (!(((originalValue & 0x0F) - (1 & 0x0F)) < 0))
{
registers.HalfCarryFlag = true;
}
//ignore carry flag
}
switch (targetRegister)
{
case IALU.TargetRegister.A:
registers.A = (byte)result;
break;
case IALU.TargetRegister.F:
registers.F = (byte)result;
break;
case IALU.TargetRegister.B:
registers.B = (byte)result;
break;
case IALU.TargetRegister.C:
registers.C = (byte)result;
break;
case IALU.TargetRegister.D:
registers.D = (byte)result;
break;
case IALU.TargetRegister.E:
registers.E = (byte)result;
break;
case IALU.TargetRegister.H:
registers.H = (byte)result;
break;
case IALU.TargetRegister.L:
registers.L = (byte)result;
break;
case IALU.TargetRegister.HL:
registers.HL = (byte)result;
break;
case IALU.TargetRegister.SP:
registers.SP = (byte)result;
break;
}
}
public void SubtractUshort(IRegisters registers, IALU.TargetRegister targetRegister, ushort value, bool useCarry)
{
int result;
switch (targetRegister)
{
case IALU.TargetRegister.AF:
result = registers.AF;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.BC:
result = registers.BC;
break;
case IALU.TargetRegister.DE:
result = registers.DE;
break;
case IALU.TargetRegister.HL:
result = registers.HL;
break;
default:
throw new ArgumentException();
}
int originalValue = result;
result -= value + (useCarry && registers.FullCarryFlag ? 1 : 0);
//Zero flag is ignored
registers.NegativeFlag = true;
if (!(((originalValue & 0x0FFF) - (value & 0x0FFF)) < 0))
{
registers.HalfCarryFlag = true;
}
if (result < 0)
{
registers.FullCarryFlag = true;
}
switch (targetRegister)
{
case IALU.TargetRegister.AF:
registers.AF = (ushort)result;
break;
case IALU.TargetRegister.BC:
registers.BC = (ushort)result;
break;
case IALU.TargetRegister.DE:
registers.DE = (ushort)result;
break;
case IALU.TargetRegister.HL:
registers.HL = (ushort)result;
break;
}
}
public void SubtractSbyte(IRegisters registers, IALU.TargetRegister targetRegister, sbyte value, bool useCarry)
{
int result;
switch (targetRegister)
{
case IALU.TargetRegister.A:
result = registers.A;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.B:
result = registers.B;
break;
case IALU.TargetRegister.C:
result = registers.C;
break;
case IALU.TargetRegister.D:
result = registers.D;
break;
case IALU.TargetRegister.E:
result = registers.E;
break;
case IALU.TargetRegister.H:
result = registers.H;
break;
case IALU.TargetRegister.L:
result = registers.L;
break;
default:
throw new ArgumentException();
}
int originalValue = result;
result -= value + (useCarry && registers.FullCarryFlag ? 1 : 0);
registers.NegativeFlag = true;
registers.ZeroFlag = false;
if (!(((originalValue & 0x0F) - (value & 0x0F)) < 0))
{
registers.HalfCarryFlag = true;
}
if (result < 0)
{
registers.FullCarryFlag = true;
}
switch (targetRegister)
{
case IALU.TargetRegister.A:
registers.A = (byte)result;
break;
case IALU.TargetRegister.F:
registers.F = (byte)result;
break;
case IALU.TargetRegister.B:
registers.B = (byte)result;
break;
case IALU.TargetRegister.C:
registers.C = (byte)result;
break;
case IALU.TargetRegister.D:
registers.D = (byte)result;
break;
case IALU.TargetRegister.E:
registers.E = (byte)result;
break;
case IALU.TargetRegister.H:
registers.H = (byte)result;
break;
case IALU.TargetRegister.L:
registers.L = (byte)result;
break;
}
}
public void RotateRegister(IRegisters registers, IALU.TargetRegister targetRegister, IALU.RotateDirection direction, bool useCarry)
{
int result;
switch (targetRegister)
{
case IALU.TargetRegister.A:
result = registers.A;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.B:
result = registers.B;
break;
case IALU.TargetRegister.C:
result = registers.C;
break;
case IALU.TargetRegister.D:
result = registers.D;
break;
case IALU.TargetRegister.E:
result = registers.E;
break;
case IALU.TargetRegister.H:
result = registers.H;
break;
case IALU.TargetRegister.L:
result = registers.L;
break;
default:
throw new ArgumentException();
}
if (direction == IALU.RotateDirection.Left)
{
if (!useCarry)
{
if ((result & 0x80) > 0)
{
registers.FullCarryFlag = true;
}
result = (result << 1) | ((result & 0x80) > 0 ? 0x01 : 0x00);
}
else
{
bool currentCarry = registers.FullCarryFlag;
if ((result & 0x80) > 0)
{
registers.FullCarryFlag = true;
}
result = (result << 1) | (currentCarry ? 0x01 : 0x00);
}
}
else
{
if (!useCarry)
{
if ((result & 0x01) > 0)
{
registers.FullCarryFlag = true;
}
result = (result >> 1) | ((result & 0x01) > 0 ? 0x80 : 0x00);
}
else
{
bool currentCarry = registers.FullCarryFlag;
if ((result & 0x10) > 0)
{
registers.FullCarryFlag = true;
}
result = (result >> 1) | (currentCarry ? 0x80 : 0x00);
}
}
registers.NegativeFlag = false;
registers.ZeroFlag = false;
registers.HalfCarryFlag = false;
switch (targetRegister)
{
case IALU.TargetRegister.A:
registers.A = (byte)result;
break;
case IALU.TargetRegister.F:
registers.F = (byte)result;
break;
case IALU.TargetRegister.B:
registers.B = (byte)result;
break;
case IALU.TargetRegister.C:
registers.C = (byte)result;
break;
case IALU.TargetRegister.D:
registers.D = (byte)result;
break;
case IALU.TargetRegister.E:
registers.E = (byte)result;
break;
case IALU.TargetRegister.H:
registers.H = (byte)result;
break;
case IALU.TargetRegister.L:
registers.L = (byte)result;
break;
}
}
public void CompareByte(IRegisters registers, IALU.TargetRegister targetRegister, byte value)
{
int result;
switch (targetRegister)
{
case IALU.TargetRegister.A:
result = registers.A;
break;
case IALU.TargetRegister.F:
result = registers.F;
break;
case IALU.TargetRegister.B:
result = registers.B;
break;
case IALU.TargetRegister.C:
result = registers.C;
break;
case IALU.TargetRegister.D:
result = registers.D;
break;
case IALU.TargetRegister.E:
result = registers.E;
break;
case IALU.TargetRegister.H:
result = registers.H;
break;
case IALU.TargetRegister.L:
result = registers.L;
break;
default:
throw new ArgumentException();
}
int originalValue = result;
result -= value;
registers.NegativeFlag = true;
if ((result & 0xFF) == 0)
{
registers.ZeroFlag = true;
}
if (!(((originalValue & 0x0F) - (value & 0x0F)) < 0))
{
registers.HalfCarryFlag = true;
}
if (result < 0)
{
registers.FullCarryFlag = true;
}
//don't register
}
