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462 lines (404 loc) · 11.4 KB
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//Mark Klara
//mak241@pitt.edu
//CS 1622 - Project 3
//CodeGenerator.java
package codegen;
import java.io.*;
import IR.*;
import helper.Label;
import symboltable.Variable;
import java.util.List;
import java.util.Hashtable;
import regalloc.RegisterAllocator;
public class CodeGenerator
{
private String output;
private List<Quadruple> IRList;
private Hashtable<Quadruple, List<Label>> labels;
private List<Variable> varList;
private RegisterAllocator allocator;
public CodeGenerator(List<Quadruple> list, Hashtable<Quadruple, List<Label>> label, List<Variable> vars, String fileName)
{
IRList = list;
output = fileName;
labels = label;
varList = vars;
allocator = new RegisterAllocator();
}
public void generateMIPS()
{
boolean printedExit = false; //Used to track the closing of main
try
{
FileWriter fw = new FileWriter(output);
BufferedWriter bw = new BufferedWriter(fw);
//Allocated Variables
bw.write(".data\n");
generateDataSeg(varList, bw);
bw.write(".text\n", 0, 6);
bw.write("main:\n", 0, 6);
//Iterate through the IR instructions
for(int i = 0; i < IRList.size(); i++)
{
Quadruple q = IRList.get(i);
List<Label> labelList = labels.get(q);
//Print any labels before this instruction
if(labelList != null)
{
for(Label l : labelList)
{
if(l.printBefore == true)
{
//Print system exit at the end of main
if(l.toString().equals("L1:"))
{
String temp = "jal _system_exit\n";
bw.write(temp, 0, temp.length());
printedExit = true;
}
else //Print jr return jump before the label
{
if(!l.toString().equals("L0:"))
{
String temp = "jr $ra\n";
bw.write(temp, 0, temp.length());
}
}
//Print label
String temp = l.toString() + "\n";
bw.write(temp, 0, temp.length());
}
}
}
if(q instanceof AssignmentIR)
{
handleAssignment(q, bw);
}
else if(q instanceof CallIR)
{
functionCall(IRList, i, bw);
}
else if(q instanceof ReturnIR)
{
handleReturn(q, bw);
}
//Print any labels after
if(labelList != null)
{
for(Label l : labelList)
{
if(l.printBefore == false)
{
//Print system exit at the end of main
if(l.toString().equals("L1:"))
{
String temp = "jal _system_exit\n";
bw.write(temp, 0, temp.length());
printedExit = true;
}
else //Print jr return jump before the label
{
if(!l.toString().equals("L0:"))
{
String temp = "jr $ra\n";
bw.write(temp, 0, temp.length());
}
}
//Print label
String temp = l.toString() + "\n";
bw.write(temp, 0, temp.length());
}
}
}
}
//Print the closing exit/return
if(printedExit == true)
{
String temp = "jr $ra\n";
bw.write(temp, 0, temp.length());
}
else
{
String temp = "jal _system_exit\n";
bw.write(temp, 0, temp.length());
}
//Close output file resources
if(bw != null)
bw.close();
}
catch (IOException e)
{
e.printStackTrace();
}
}
private void generateDataSeg(List<Variable> varList, BufferedWriter bw)
{
for(int i = 0; i < varList.size(); i++)
{
try
{
String name = varList.get(i).getName();
String type = varList.get(i).getType();
String value = "";
if(type.equals("int") || type.equals("boolean"))
{
type = ".word";
value = "0"; //Default value of 0d or false
}
else //Don't handle objects or int[] yet
{
return;
}
String data = name + ": " + type + " " + value + "\n";
bw.write(data, 0, data.length());
}
catch (IOException e)
{
e.printStackTrace();
}
}
}
private void handleReturn(Quadruple instruction, BufferedWriter bw)
{
try
{
Variable arg1 = (Variable)instruction.getArg1();
String temp = "";
if(arg1.getType().equals("constant"))
{
temp = "li $v0, " + arg1.getName() + "\n";
}
else if(arg1.getType().equals("temporary"))
{
temp = "move $v0, " + allocator.allocateReg(arg1.getName()) + "\n";
}
else //Variable
{
temp = "lw $v0, " + arg1.getName() + "\n";
}
bw.write(temp, 0, temp.length());
}
catch(IOException e)
{
e.printStackTrace();
}
}
private void handleAssignment(Quadruple instruction, BufferedWriter bw)
{
try
{
String op = (String)instruction.getOp();
Variable result = (Variable)instruction.getResult();
Variable arg1 = (Variable)instruction.getArg1();
Variable arg2 = (Variable)instruction.getArg2();
String temp = "";
if(op.equals("+"))
{
if(result.getType().equals("temporary"))
{
String resultReg = allocator.allocateReg(result.getName());
//Handle arg1 -- Store the first parameter in the result register
if(arg1.getType().equals("constant"))
{
temp = "li " + resultReg + ", " + arg1.getName() + "\n";
}
else if(arg1.getType().equals("temporary"))
{
temp = "move " + resultReg + ", " + allocator.allocateReg(arg1.getName()) + "\n";
}
else //Variable arg1
{
temp = "lw " + resultReg + ", " + arg1.getName() + "\n";
}
bw.write(temp, 0, temp.length());
//Handle arg2 -- Add it to the second parameter in the result register
if(arg2.getType().equals("constant"))
{
temp = "addi " + resultReg + ", " + resultReg + ", " + arg2.getName() + "\n";
}
else if(arg2.getType().equals("temporary"))
{
temp = "add " + resultReg + ", " + resultReg + ", " + allocator.allocateReg(arg2.getName()) + "\n";
}
else //Variable arg2
{
String tempReg = allocator.allocateTempReg(0);
temp = "lw " + tempReg + ", " + arg2.getName() + "\n";
bw.write(temp, 0, temp.length());
temp = "add " + resultReg + ", " + resultReg + ", " + tempReg + "\n";
}
bw.write(temp, 0, temp.length());
}
else //Variable result
{
String resultReg = allocator.allocateTempReg(0);
String tempReg = allocator.allocateTempReg(1);
String resultName = (String)result.getName();
//Handle arg1 -- Store the first parameter in the temporary register
if(arg1.getType().equals("constant"))
{
temp = "li " + tempReg + ", " + arg1.getName() + "\n";
}
else if(arg1.getType().equals("temporary"))
{
temp = "move " + tempReg + ", " + allocator.allocateReg(arg1.getName()) + "\n";
}
else //Variable arg1
{
temp = "lw " + tempReg + ", " + arg1.getName() + "\n";
}
bw.write(temp, 0, temp.length());
//Handle arg2 -- Add it to the second parameter in the temp register
if(arg2.getType().equals("constant"))
{
temp = "addi " + tempReg + ", " + tempReg + ", " + arg2.getName() + "\n";
}
else if(arg2.getType().equals("temporary"))
{
temp = "add " + tempReg + ", " + tempReg + ", " + allocator.allocateReg(arg2.getName()) + "\n";
}
else //Variable arg2
{
temp = "lw " + resultReg + ", " + arg2.getName() + "\n"; //Use "resultReg" as a temporary register here
bw.write(temp, 0, temp.length());
temp = "add " + tempReg + ", " + tempReg + ", " + resultReg;
}
bw.write(temp, 0, temp.length());
//Load address of variable
temp = "la " + resultReg + ", " + resultName + "\n";
bw.write(temp, 0, temp.length());
//Store result from tempReg into the variable address
temp = "sw " + tempReg + ", 0(" + resultReg + ")\n";
bw.write(temp, 0, temp.length());
}
}
else if(op.equals("-")) //Subtraction
{
//To be completed...
}
else if(op.equals("*")) //Multiplication
{
//To be completed...
}
else if(op.equals("<")) //Less Than
{
//To be completed...
}
else //And
{
//To be completed...
}
}
catch (IOException e)
{
e.printStackTrace();
}
}
private void functionCall(List<Quadruple>IRList, int index, BufferedWriter bw)
{
try
{
CallIR instruction = (CallIR)IRList.get(index);
int paramCount = Integer.parseInt((String)instruction.getArg2());
//Store $ra on stack
String temp = "addi $sp, $sp, -68\n"; //Make enough space on stack to save all reg
bw.write(temp, 0, temp.length());
temp = "sw $ra, 64($sp)\n";
bw.write(temp, 0, temp.length());
//Store $a0 - $a3 on stack
for(int i = 0; i < 4; i++)
{
temp = "sw $a" + i + ", " + (60 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Store $t0-$t9 on the stack
for(int i = 0; i < 10; i++)
{
temp = "sw $t" + i + ", " + (44 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Store $v0-$v1 on the stack
for(int i = 0; i < 2; i++)
{
temp = "sw $v" + i + ", " + (4 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Store the (up to 4) params in register
if(paramCount > 4)
{
System.err.println("Invalid number of parameters. A max of 4 params per function in our MIPS output.");
return;
}
int paramIndex = index - paramCount;
for(int i = 0; i < paramCount; i++)
{
ParameterIR param = (ParameterIR)IRList.get(paramIndex+i);
String reg = "$a" + i;
String argName = ((Variable)param.getArg1()).getName();
String argType = ((Variable)param.getArg1()).getType();
if(argType.equals("constant"))
{
temp = "li " + reg + ", " + argName + "\n";
}
else if(argType.equals("temporary"))
{
temp = "move " + reg + ", " + allocator.allocateReg(argName) + "\n";
}
else //Variable
{
temp = "lw " + reg + ", " + argName + "\n";
}
bw.write(temp, 0, temp.length());
}
//Jump to the function
String function = (String)instruction.getArg1();
if(function.equals("System.out.println") == true)
{
function = "_system_out_println";
}
temp = "jal " + function + "\n";
bw.write(temp, 0, temp.length());
//Restore $t0-$t9 from the stack
for(int i = 9; i >= 0; i--)
{
temp = "lw $t" + i + ", " + (44 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Restore $a0-$a3 on the stack
for(int i = 3; i >= 0; i--)
{
temp = "lw $a" + i + ", " + (60 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Move return value into the result register
if(!function.equals("_system_out_println")) //println is the only 'void' function in minijava
{
Variable result = (Variable)instruction.getResult();
if(result.getType().equals("temporary"))
{
temp = "move " + allocator.allocateReg(result.getName()) + ", $v0\n";
}
else //Variable
{
temp = "sw $v0, " + result.getName() + "\n";
}
bw.write(temp, 0, temp.length());
}
//Restore $v0-$v1 from the stack
for(int i = 1; i >= 0; i--)
{
temp = "lw $v" + i + ", " + (4 - (4*i)) + "($sp)\n";
bw.write(temp, 0, temp.length());
}
//Restore $ra from the stack
temp = "lw $ra, 64($sp)\n";
bw.write(temp, 0, temp.length());
temp = "addi $sp, $sp, 68\n"; //Cleanup space on stack from all saved reg
bw.write(temp, 0, temp.length());
}
catch (IOException e)
{
e.printStackTrace();
}
}
}