private List <IMOperation> GenerateStringConcat(IMGeneratorEnv env, IMOperand target, IMOperand operand1, IMOperand operand2)
{
var result = new List <IMOperation>(20);
var op1LengthLocation = IMOperand.Reference(DataType.U64, operand1);
var op2LengthLocation = IMOperand.Reference(DataType.U64, operand2);
//Calculate new string length
var lengthLocation = env.NewTempLocal(DataType.U64);
result.Add(IMOperation.Mov(lengthLocation, op1LengthLocation));
result.Add(IMOperation.Add(lengthLocation, lengthLocation, op2LengthLocation));
//Calculate new string byte size
var byteSizeLocation = env.NewTempLocal(DataType.U64);
result.Add(IMOperation.Mov(byteSizeLocation, lengthLocation));
result.Add(IMOperation.Add(lengthLocation, lengthLocation, IMOperand.Immediate(DataType.U64, 9L)));
//Reserve new memory on stack, which is freed automatically
result.Add(IMOperation.SAloc(target, byteSizeLocation));
//Copy target address
var targetAddressLocation = env.NewTempLocal(target.DataType);
result.Add(IMOperation.Mov(targetAddressLocation, target));
//Write new string length to target
result.Add(IMOperation.Mov(IMOperand.Reference(DataType.U64, targetAddressLocation), lengthLocation));
//Move pointer to first char
result.Add(IMOperation.Add(targetAddressLocation, targetAddressLocation, IMOperand.Immediate(DataType.U64, 8L)));
var targetRefLocation = IMOperand.Reference(DataType.CHAR8, targetAddressLocation);
//Get address of first char of operand1
var sourceAddressLocation = env.NewTempLocal(target.DataType);
result.Add(IMOperation.Mov(sourceAddressLocation, operand1));
result.Add(IMOperation.Add(sourceAddressLocation, sourceAddressLocation, IMOperand.Immediate(DataType.U64, 8L)));
var sourceRefLocation = IMOperand.Reference(DataType.CHAR8, sourceAddressLocation);
var startLabel = env.NewLabelName();
var endLabel = env.NewLabelName();
//Start label
result.Add(IMOperation.Labl(startLabel));
//Check if more chars to copy (string ends with 0 char)
result.Add(IMOperation.JmpE(sourceRefLocation, IMOperand.Immediate(DataType.CHAR8, "\0"), endLabel));
//Copy char
result.Add(IMOperation.Mov(targetRefLocation, sourceRefLocation));
//Inc target and source pointers
result.Add(IMOperation.Add(targetAddressLocation, targetAddressLocation, IMOperand.Immediate(DataType.U64, 1L)));
result.Add(IMOperation.Add(sourceAddressLocation, sourceAddressLocation, IMOperand.Immediate(DataType.U64, 1L)));
//Next iteration
result.Add(IMOperation.Jmp(startLabel));
result.Add(IMOperation.Labl(endLabel));
//Get address of first char of operand2
result.Add(IMOperation.Mov(sourceAddressLocation, operand2));
result.Add(IMOperation.Add(sourceAddressLocation, sourceAddressLocation, IMOperand.Immediate(DataType.U64, 8L)));
startLabel = env.NewLabelName();
endLabel = env.NewLabelName();
//Start label
result.Add(IMOperation.Labl(startLabel));
//Check if more chars to copy (string ends with 0 char)
result.Add(IMOperation.JmpE(sourceRefLocation, IMOperand.Immediate(DataType.CHAR8, "\0"), endLabel));
//Copy char
result.Add(IMOperation.Mov(targetRefLocation, sourceRefLocation));
//Inc target and source pointers
result.Add(IMOperation.Add(targetAddressLocation, targetAddressLocation, IMOperand.Immediate(DataType.U64, 1L)));
result.Add(IMOperation.Add(sourceAddressLocation, sourceAddressLocation, IMOperand.Immediate(DataType.U64, 1L)));
//Next iteration
result.Add(IMOperation.Jmp(startLabel));
result.Add(IMOperation.Labl(endLabel));
//Terminating 0
result.Add(IMOperation.Mov(targetRefLocation, IMOperand.Immediate(DataType.U8, (byte)0)));
return(result);
}
