/// <summary>
/// Parses an instruction and generates the binary code for it.
/// </summary>
/// <param name="address">The address of the instruction being parsed in the .text segment.</param>
/// <param name="args">An array containing the arguments of the instruction.</param>
/// <returns>One or more 32-bit integers representing this instruction. If this interface is implemented
/// for a pseudo-instruction, this may return more than one instruction value.</returns>
public override IEnumerable <int> GenerateCodeForInstruction(int nextTextAddress, string[] args)
{
if (args.Length != 2)
{
throw new ArgumentException("Invalid number of arguments provided. Expected 2, received " + args.Length + '.');
}
int rs2 = RegisterMap.GetNumericFloatingPointRegisterValue(args[0]);
var retList = new List <int>();
ParameterizedInstructionArg arg = ParameterizedInstructionArg.ParameterizeArgument(args[1]);
int instruction = 0;
int upperOffset = (arg.Offset & 0xFE0);
int lowerOffset = (arg.Offset & 0x1F);
instruction |= (upperOffset << 25);
instruction |= (rs2 << 20);
instruction |= (arg.Register << 15);
const int FUNC_CODE = 2;
instruction |= (FUNC_CODE << 12);
instruction |= (lowerOffset << 7);
instruction |= 0x27;
retList.Add(instruction);
return(retList);
}
/// <summary>
/// Takes an argument (e.g. 4(x9)) and parameterizes it into the offset component
/// and its numeric register ID.
/// </summary>
/// <param name="trimmedArgToken">The token to parameterize, with whitespace trimmed on both left/right sides.</param>
/// <returns>A parameterized register/offset structure.</returns>
public static ParameterizedInstructionArg ParameterizeArgument(string trimmedArgToken)
{
string[] parameterizedArgs = trimmedArgToken.Split(new[] { '(', ')' }, StringSplitOptions.RemoveEmptyEntries).Apply((str) => str.Trim()).ToArray();
// we should expect one or two arguments.
if (parameterizedArgs.Length != 1 && parameterizedArgs.Length != 2)
{
throw new ArgumentException(trimmedArgToken + " was not in a valid format.");
}
ParameterizedInstructionArg retVal = default(ParameterizedInstructionArg);
// if we have one argument, assume its the register name, and that the offset is 0.
if (parameterizedArgs.Length == 1)
{
int registerId = RegisterMap.GetNumericRegisterValue(parameterizedArgs[0]);
retVal = new ParameterizedInstructionArg(0, registerId);
}
else
{
bool isValidOffset = IntExtensions.TryParseEx(parameterizedArgs[0], out short offsetVal) && ((offsetVal & 0xF000) == 0);
if (!isValidOffset)
{
throw new ArgumentException(parameterizedArgs[0] + " is not a valid 12-bit offset.");
}
int registerId = RegisterMap.GetNumericRegisterValue(parameterizedArgs[1]);
retVal = new ParameterizedInstructionArg(offsetVal, registerId);
}
return(retVal);
}
/// <summary>
/// Parses an instruction and generates the binary code for it.
/// </summary>
/// <param name="address">The address of the instruction being parsed in the .text segment.</param>
/// <param name="args">An array containing the arguments of the instruction.</param>
/// <returns>One or more 32-bit integers representing this instruction. If this interface is implemented
/// for a pseudo-instruction, this may return more than one instruction value.</returns>
public override IEnumerable <int> GenerateCodeForInstruction(int address, string[] args)
{
if (args.Length != 2)
{
throw new ArgumentException("Invalid number of arguments provided. Expected 2, received " + args.Length + '.');
}
int rdReg = RegisterMap.GetNumericFloatingPointRegisterValue(args[0]);
var retList = new List <int>();
const int FUNC_CODE = 0x2;
if (IsParameterizedToken(args[1]))
{
ParameterizedInstructionArg arg = ParameterizedInstructionArg.ParameterizeArgument(args[1]);
int instruction = 0;
instruction |= ((arg.Offset & 0xFFF) << 20);
instruction |= (arg.Register << 15);
instruction |= (FUNC_CODE << 12);
instruction |= (rdReg << 7);
instruction |= 0x7;
retList.Add(instruction);
}
else
{
Symbol sym = SymbolTable.GetSymbol(args[1]);
int shiftedAddress = sym.Address >> 12;
retList.AddRange(new LuiProcessor().GenerateCodeForInstruction(address, new[] { args[0], shiftedAddress.ToString() }));
int numericOffset = sym.Address & 0xFFF;
int instruction = 0;
instruction |= (numericOffset << 20);
instruction |= (rdReg << 15);
instruction |= (FUNC_CODE << 12);
instruction |= (rdReg << 7);
instruction |= 0x7;
retList.Add(instruction);
}
return(retList);
}
