private void Load(string[] operands)
{
if (operands.Length == 2)
{
if (RegisterSyntax.TryParse(operands[0], out var register) && AddressSyntax.TryParse(operands[1], _symbolTable, out var address))
{
_bytes.Add(((byte)Opcode.ImmediateLoad, register.Index).Combine(), _currentLineNumber);
_bytes.Add(address, _currentLineNumber);
return;
}
if (RegisterSyntax.TryParse(operands[0], out register) && AddressSyntax.TryParse(operands[1], _symbolTable, out address, BracketExpectation.Present))
{
_bytes.Add(((byte)Opcode.DirectLoad, register.Index).Combine(), _currentLineNumber);
_bytes.Add(address, _currentLineNumber);
return;
}
if (RegisterSyntax.TryParse(operands[0], out var register1) && RegisterSyntax.TryParse(operands[1], out var register2, BracketExpectation.Present))
{
_bytes.Add(((byte)Opcode.IndirectLoad, (byte)0x0).Combine(), _currentLineNumber);
_bytes.Add((register1.Index, register2.Index).Combine(), _currentLineNumber);
return;
}
}
throw new AssemblyException("Invalid operands for load instruction.", _currentLineNumber);
}
private void JmpEQ(string[] operands)
{
if (operands.Length == 2)
{
string[] registers = operands[0].Split('=');
if (!RegisterSyntax.TryParse(registers[1], out var rightRegister) || rightRegister.Index != 0)
{
throw new AssemblyException("Expected a comparison with R0.", _currentLineNumber);
}
if (RegisterSyntax.TryParse(registers[0], out var leftRegister) && AddressSyntax.TryParse(operands[1], _symbolTable, out var address))
{
_bytes.Add(((byte)Opcode.JumpEqual, leftRegister.Index).Combine(), _currentLineNumber);
_bytes.Add(address, _currentLineNumber);
return;
}
}
throw new AssemblyException("Invalid operands for jmpeq instruction.", _currentLineNumber);
}
private void Jmp(string[] operands)
{
bool invalidSyntax = false;
if (operands.Length != 1)
{
invalidSyntax = true;
}
else if (AddressSyntax.TryParse(operands[0], _symbolTable, out var address))
{
_bytes.Add(((byte)Opcode.JumpEqual, (byte)0x0).Combine(), _currentLineNumber);
_bytes.Add(address, _currentLineNumber);
}
else
{
invalidSyntax = true;
}
if (invalidSyntax)
{
throw new AssemblyException("Expected a single address.", _currentLineNumber);
}
}
private void JmpLE(string[] operands)
{
if (operands.Length == 2)
{
if (RegisterSyntax.TryParse(operands[0].Split('<', '=')[0], out var register) && AddressSyntax.TryParse(operands[1], _symbolTable, out var address))
{
_bytes.Add(((byte)Opcode.JumpLessEqual, register.Index).Combine(), _currentLineNumber);
_bytes.Add(address, _currentLineNumber);
return;
}
}
throw new AssemblyException("Invalid operands for jmple instruction.", _currentLineNumber);
}