void Halt(HaltCode code)
{
// TODO: add halt reasong as parameter and support in translator
NextState.State = CPUState.Halt;
NextState.HaltCode = code;
// calls to Debugger and Trace are not translated into HDL.
Trace.WriteLine($"CPU halted: {code}");
Debugger.Break();
}
/// <summary>
/// Execute a program
/// </summary>
/// <returns>Boolean based on how program stopped, false if it can be continued (opcode 99) or true if its waiting on input</returns>
public HaltCode ExecuteProgram(int startOpcodeAddress = 0)
{
// stop immediately if start address is out of memory
if (startOpcodeAddress < 0 || startOpcodeAddress >= memory.Length)
{
LastHaltCode = HaltCode.InvalidPointer;
return(HaltCode.InvalidPointer);
}
// pointer to address of current opcode
int opcodePointer = startOpcodeAddress;
// possible parameters
long a, b;
while (true)
{
// get op code
long opCode = memory[opcodePointer];
long[] param;
switch (opCode % 100)
{
// +
case 1:
param = GetParameters(opcodePointer, 2);
a = param[0];
b = param[1];
if ((memory[opcodePointer] / 100_0_0) % 10 == 2)
{
SetMemory(memory[opcodePointer + 3] + relativeBase, a + b);
}
else if ((memory[opcodePointer] / 100_0_0) % 10 == 0)
{
SetMemory(memory[opcodePointer + 3], a + b);
}
/// <summary>
/// Execute loaded program
/// </summary>
/// <returns>Reason for halting VM</returns>
public HaltCode ExecuteProgram(long startAddress = 0)
{
// stop immediately if start address is negative
if (startAddress < 0)
{
LastHaltReason = HaltCode.InvalidOpCodePointer;
return(HaltCode.InvalidOpCodePointer);
}
// pointer to address of current opcode
long opcodePointer = startAddress;
// parameters
long[] longParams;
// execute program
while (true)
{
long opCode = GetMemory(opcodePointer);
// instruction
switch (opCode % 100)
{
// addition
case 1:
longParams = GetParamAddresses(opcodePointer, 3);
SetMemory(longParams[2], GetMemory(longParams[0]) + GetMemory(longParams[1]));
opcodePointer += 4;
break;
// multiplication
case 2:
longParams = GetParamAddresses(opcodePointer, 3);
SetMemory(longParams[2], GetMemory(longParams[0]) * GetMemory(longParams[1]));
opcodePointer += 4;
break;
// get input
case 3:
longParams = GetParamAddresses(opcodePointer, 1);
long?input = GetNextInput();
// halt VM till input is given
if (input == null)
{
pausedOpCodePointer = opcodePointer;
LastHaltReason = HaltCode.WaitingForInput;
return(HaltCode.WaitingForInput);
}
else
{
SetMemory(longParams[0], (long)input);
}
opcodePointer += 2;
break;
// output
case 4:
longParams = GetParamAddresses(opcodePointer, 1);
outputs.Add(GetMemory(longParams[0]));
opcodePointer += 2;
break;
// jump if not zero
case 5:
longParams = GetParamAddresses(opcodePointer, 2);
if (GetMemory(longParams[0]) != 0L)
{
opcodePointer = GetMemory(longParams[1]);
}
else
{
opcodePointer += 3;
}
break;
// jump if zero
case 6:
longParams = GetParamAddresses(opcodePointer, 2);
if (GetMemory(longParams[0]) == 0L)
{
opcodePointer = GetMemory(longParams[1]);
}
else
{
opcodePointer += 3;
}
break;
// less than
case 7:
longParams = GetParamAddresses(opcodePointer, 3);
SetMemory(longParams[2], GetMemory(longParams[0]) < GetMemory(longParams[1]) ? 1 : 0);
opcodePointer += 4;
break;
// equals
case 8:
longParams = GetParamAddresses(opcodePointer, 3);
SetMemory(longParams[2], GetMemory(longParams[0]) == GetMemory(longParams[1]) ? 1 : 0);
opcodePointer += 4;
break;
// change base offset
case 9:
longParams = GetParamAddresses(opcodePointer, 1);
baseOffset += GetMemory(longParams[0]);
opcodePointer += 2;
break;
// end program
case 99:
LastHaltReason = HaltCode.Finished;
return(HaltCode.Finished);
// unknown opcode
default:
// write error to console
Console.BackgroundColor = ConsoleColor.Black;
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine($"Fatal VM error: unknown opcode {opCode % 100} ({opCode}) at address {opcodePointer}");
Console.ForegroundColor = ConsoleColor.White;
LastHaltReason = HaltCode.UnknownOpCode;
return(HaltCode.UnknownOpCode);
}
}
}
public void Visit(HaltCode code)
{
}
