/// <summary>
/// Method for performing MUL instruction
/// </summary>
public static bool Multiply(ModuleBase module, MixInstruction.Instance instance)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress == int.MinValue)
{
return(false);
}
Register rA = module.Registers.RA;
Register rX = module.Registers.RX;
long rAValue = rA.LongValue;
long memoryWordValue = WordField.LoadFromFullWord(instance.FieldSpec, module.Memory[indexedAddress]).LongValue;
var result = decimal.Multiply(rAValue, memoryWordValue);
rA.Sign = rX.Sign = result.GetSign();
result = result.GetMagnitude();
var rXResultValue = (long)(result % ((long)1 << rX.BitCount));
var rAResultValue = (long)decimal.Truncate(result / ((long)1 << rX.BitCount));
rA.MagnitudeLongValue = rAResultValue;
rX.MagnitudeLongValue = rXResultValue;
return(true);
}
/// <summary>
/// Method for performing the STZ instruction
/// </summary>
public static bool StoreZero(ModuleBase module, MixInstruction.Instance instance)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress != int.MinValue)
{
var word = new FullWord();
WordField.LoadFromFullWord(instance.FieldSpec, word).ApplyToFullWord(module.Memory[indexedAddress]);
}
return(true);
}
/// <summary>
/// Method for performing CMPx instructions
/// </summary>
public static bool Compare(ModuleBase module, MixInstruction.Instance instance)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress == int.MinValue)
{
return(false);
}
int registerIndex = instance.MixInstruction.Opcode - opcodeBase;
Register register = module.Registers[registerIndex];
module.Registers.CompareIndicator = WordField.LoadFromFullWord(instance.FieldSpec, register.FullWordValue).CompareTo(module.Memory[indexedAddress]).ToCompValue();
return(true);
}
/// <summary>
/// Method for performing DIV instruction
/// </summary>
public static bool Divide(ModuleBase module, MixInstruction.Instance instance)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress == int.MinValue)
{
return(false);
}
long memoryWordValue = WordField.LoadFromFullWord(instance.FieldSpec, module.Memory[indexedAddress]).LongValue;
if (memoryWordValue == 0L)
{
module.ReportOverflow();
return(true);
}
Register rA = module.Registers.RA;
Register rX = module.Registers.RX;
long rAValue = rA.LongValue;
long rXValue = rX.LongValue;
decimal rAXValue = (decimal)rAValue * ((long)1 << rX.BitCount) + rXValue;
decimal divider = rAXValue / memoryWordValue;
rX.Sign = rA.Sign;
rA.Sign = divider.GetSign();
divider = divider.GetMagnitude();
if (divider > rA.MaxMagnitude)
{
module.ReportOverflow();
return(true);
}
decimal remainder = rAXValue % memoryWordValue;
rA.MagnitudeLongValue = (long)divider;
rX.MagnitudeLongValue = (long)remainder;
return(true);
}
static bool DoLoad(ModuleBase module, MixInstruction.Instance instance, int registerIndex, bool negateSign)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress == int.MinValue)
{
return(false);
}
var memoryField = WordField.LoadFromFullWord(instance.FieldSpec, module.Memory[indexedAddress]);
if (negateSign)
{
memoryField.InvertSign();
}
memoryField.ApplyToRegister(module.Registers[registerIndex]);
return(true);
}
/// <summary>
/// Method for performing ADD and SUB instructions
/// </summary>
public static bool AddSubstract(ModuleBase module, MixInstruction.Instance instance)
{
var indexedAddress = InstructionHelpers.GetValidIndexedAddress(module, instance.AddressValue, instance.Index);
if (indexedAddress == int.MinValue)
{
return(false);
}
Register rA = module.Registers.RA;
long rALongValue = rA.LongValue;
long memoryWordValue = WordField.LoadFromFullWord(instance.FieldSpec, module.Memory[indexedAddress]).LongValue;
if (instance.MixInstruction.Opcode == substractOpcode)
{
memoryWordValue = -memoryWordValue;
}
long sumValue = rALongValue + memoryWordValue;
if (sumValue != 0L)
{
rA.Sign = sumValue.GetSign();
sumValue = sumValue.GetMagnitude();
}
if (sumValue > rA.MaxMagnitude)
{
module.ReportOverflow();
sumValue &= rA.MaxMagnitude;
}
rA.MagnitudeLongValue = sumValue;
return(true);
}