assembler.cpp

/******************************************************************************
Filename: Assembler.cpp
By: Matthew DeBord and Ronald Radut
Created: 04/11/2011
Last Modified: 04/20/2011
Description: This cpp code builds and executes the
assembler turning our .s to .o
******************************************************************************/
#include <iostream>
#include <sstream>
#include <vector>
#include "Assembler.h"
using namespace std;

Assembler::Assembler()
{
    this->rd=-1;
    this->rs=-1;
    this->constant=-129;
}
void Assembler::assemble()
{
    fstream assemblyProg;
    assemblyProg.open("prog.s", ios::in);
    if (!assemblyProg.is_open()) {
    cout << "prog.s failed to open.\n";
    exit(1);
    }

    getline(assemblyProg, this->line);
    while (!assemblyProg.eof())
    {
        defineInst(this->line); // send line to defineInst to be parsed
        getline(assemblyProg, this->line);
    }
    assemblyProg.close();

    fstream outFile;
    outFile.open("prog.o", ios::out);
    for (int i=0;i<v.size();i++)
        {
        outFile << v[i] << endl; // write each instruction to a new line in the prog.o file.
        }
    outFile.close();
}
void Assembler::defineInst(string line)
{
        istringstream str(line.c_str()); //convert to c-string
        str >> opcode;
        if (opcode!="!")
        {
            if (opcode == "load")
            {
                optemp = 0;
                imm = 0;
                str >> rd >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }


            else if (opcode == "loadi")
            {
                optemp = 0;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }

            else if (opcode == "store")
            {
                optemp = 1;
                imm = 0;
                str >> rd >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }

            else if (opcode == "add")
            {
                optemp = 2;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                v.push_back(instruction);
            }

            else if (opcode == "addi") //set carry
            {
                optemp = 2;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }

            else if (opcode == "addc") //set carry
            {
                optemp = 3;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                v.push_back(instruction);
            }

            else if (opcode == "addci") //set carry
            {
                optemp = 3;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }

            else if (opcode == "sub") //set carry
            {
                optemp = 4;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                cout << instruction;
            }
            else if (opcode == "subi") //set carry
            {
                optemp = 4;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }
            else if (opcode == "subc") //set carry
            {
                optemp = 5;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                cout << instruction;
            }
            else if (opcode == "subci") //set carry
            {
                optemp = 5;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }
            else if (opcode == "and")
            {
                optemp = 6;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                cout << instruction;
            }
            else if (opcode == "andi")
            {
                optemp = 6;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }
            else if (opcode == "xor")
            {
                optemp = 7;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                cout << instruction;
            }
            else if (opcode == "xori")
            {
                optemp = 7;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }
            else if (opcode == "compl")
            {
                optemp = 8;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "shl") //set carry
            {
                optemp = 9;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "shla") //set carry and sign extend
            {
                optemp = 10;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "shr") //set carry
            {
                optemp = 11;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "shra") //set carry and sign extend
            {
                optemp = 12;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "compr")
            {
                optemp = 13;
                imm = 0;
                str >> rd >> rs;
                int instruction = buildFormat1(optemp, rd, rs, imm);
                cout << instruction;
            }
            else if (opcode == "compri")
            {
                optemp = 13;
                imm = 1;
                str >> rd >> constant;
                int instruction = buildFormat2(optemp, rd, imm, constant);
                v.push_back(instruction);
            }
            else if (opcode == "getstat")
            {
                optemp = 14;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "putstat")
            {
                optemp = 15;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "jump")
            {
                optemp = 16;
                imm = 0;
                str >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }
            else if (opcode == "jumpl")
            {
                optemp = 17;
                imm = 0;
                str >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }
            else if (opcode == "jumpe")
            {
                optemp = 18;
                imm = 0;
                str >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }
            else if (opcode == "jumpg")
            {
                optemp = 19;
                imm = 0;
                str >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }
            else if (opcode == "call")
            {
                optemp = 20;
                imm = 0;
                str >> address;
                int instruction = buildFormat2(optemp, rd, imm, address);
                v.push_back(instruction);
            }
            else if (opcode == "return")
            {
                optemp = 21;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "read")
            {
                optemp = 22;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "write")
            {
                optemp = 23;
                imm = 0;
                str >> rd;
                int instruction = buildFormat2(optemp, rd, imm, 0);
                v.push_back(instruction);
            }
            else if (opcode == "halt")
            {
                optemp = 24;
                imm = 0;
                optemp = optemp << 11;
                int instruction = optemp;
                v.push_back(instruction);
            }
            else if (opcode == "noop")
            {
                optemp = 25;
                imm = 0;
                optemp = optemp << 11;
                int instruction = optemp;
                v.push_back(instruction);
            }

            else
            {
                cout << "OPCODE:" << opcode << " is unkown." << endl << "Press any key to exit." << endl;
                cin.get();
                exit(1);
            }
        }
}
int Assembler::buildFormat1(int opcode, int rd, int rs, int imm)
{
    if (rd<0||rd>3||rs<0||rs>3) // error checking for legal register values
        {
            cout << "Invalid register" << endl << "Press any key to exit";
            cin.get();
            exit(1);
        }
    int finalvalue;
    opcode = opcode <<11; // begin bit shifts
    rd = rd << 9;
    rs = rs << 6;
    imm = imm << 8;
    finalvalue = opcode+rd+rs+imm;
    return finalvalue;
}
int Assembler::buildFormat2(int opcode, int rd, int imm, int tail)
{
    if (rd<0||rd>3) // error checking for legal register values
        {
            cout << "Invalid register" << endl << "Press any key to exit";
            cin.get();
            exit(1);
        }
    int finalvalue;
    opcode = opcode << 11; // begin bit shifts
    rd = rd << 9;
    imm = imm << 8;
    if (tail<0) // must use masking to get the final 2's compliment value inserted to rightmost 8 bits of instruction.
        {
        finalvalue = opcode+rd+imm;
        finalvalue = finalvalue + 255;
        finalvalue = tail&finalvalue;
        }
    else
        {
        finalvalue = opcode+rd+imm+tail;
        }
    return finalvalue;
}