//File codegen.cpp

#include "codegen.h"
#include "token.h"
#include "quad.h"
#include "instlist.h"
#include "pmglobs.h"
#include "qadfiler.h"
#include "codfiler.h"
#include <iostream.h>
#include <stdlib.h>
#include <string.h>

void codegenerator::distributeprogname(char* pname) {
  char fname[STRSIZE];
  int len=strlen(pname)-3;
  strncpy(fname,pname,len);
  fname[len]='\0';
  strcat(fname,".qad");
  qf.store(fname);
  len=strlen(fname)-4;
  fname[len]='\0';
  strcat(fname,".cod");
  cf.store(fname);
};

void codegenerator::emitallinsts() {
  instruction inst;
  instnode* q;
  headnode* p=ilist.head;
  while (p!=NULL) {
    q=p->nextinst;
    while (q!=NULL) {
      inst.setopcode(q->opcode);
      inst.setopnd(q->operand);
      cf.emitcode(inst);
      q=q->nextinst;
    };
    p=p->nexthead;
  };
};

void codegenerator::setaddrmode(int& opco,token& opnd) {
//sets appropriate opcodes to frame direct and immediate addressing
  switch (opnd.getclass()) {
    case 1: case 4: if (opnd.getvalue()/LEVEL0ADDRSHIFT==0)
		      opco+=5;
		    else
		      opnd.setvalue(opnd.getvalue()%LEVEL0ADDRSHIFT);
		    break;
    case 2: case 3: opco++;
		    break;
    default:        cout<<"\nError in opnd class of a quadruple!\n";
		    opnd.show();
		    exit(1);
  };
};

void codegenerator::generate() {
  token temp;
  quadruple quad;
  int opcode;
  int instnum,curinstnum;
  temp.setclass(tokenclass(0));
  instnum=0;
  boolean endcodegeneration=FALSE;
  qf.retrievequadfile();
  while (!endcodegeneration) {
    quad=qf.getnextquad();
    ilist.createentry(quad);
    switch (quad.oper) {
      case assignop:  opcode=110;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //LDA
		      temp.setclass(tokenclass(1));
		      temp.setvalue(quad.result);
		      opcode=160;
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //STA
		      instnum+=2;
		      break;
      case get:       opcode=520;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //SII
		      instnum+=1;
		      break;
      case put:       opcode=500;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //LIO
		      instnum+=1;
		      break;
      case addop:
      case subop:
      case mulop:
      case divop:     opcode=110;
		      setaddrmode(opcode,quad.opnd2);
		      ilist.enterinst(opcode,quad.opnd2);           //LDA
		      switch (quad.oper) {
			case addop: opcode=210; break;              //ADA
			case subop: opcode=260; break;              //SBA
			case mulop: opcode=310; break;              //MLA
			case divop: opcode=360; break;              //DVA
		      };
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);
		      temp.setclass(tokenclass(4));
		      temp.setvalue(quad.result);
		      opcode=160;
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //STA
		      instnum+=3;
		      break;
      case eqop:
      case noteqop:
      case lessop:
      case greaterop:
      case lesseqop:
      case greateqop: opcode=110;
		      setaddrmode(opcode,quad.opnd2);
		      ilist.enterinst(opcode,quad.opnd2);           //LDA
		      opcode=460;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //CPA
		      curinstnum=instnum+2;
		      temp.setclass(tokenclass(2));
		      temp.setvalue(curinstnum+3);
		      switch (quad.oper) {
			case eqop:     ilist.enterinst(820,temp);break; //JEQ
			case noteqop:  ilist.enterinst(850,temp);break; //JNE
			case lessop:   ilist.enterinst(810,temp);break; //JLT
			case greaterop:ilist.enterinst(830,temp);break; //JGT
			case lesseqop: ilist.enterinst(860,temp);break; //JLE
			case greateqop:ilist.enterinst(840,temp);break; //JGE
		      };
		      temp.setclass(tokenclass(2));
		      temp.setvalue(0);
		      ilist.enterinst(111,temp);                    //LDA# 0
		      curinstnum=instnum+2+2;
		      temp.setclass(tokenclass(2));
		      temp.setvalue(curinstnum+2);
		      ilist.enterinst(800,temp);                    //JMP
		      temp.setclass(tokenclass(2));
		      temp.setvalue(1);
		      ilist.enterinst(111,temp);                    //LDA# 1
		      opcode=160;
		      temp.setclass(tokenclass(4));
		      temp.setvalue(quad.result);
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //STA
		      instnum+=7;
		      break;
      case not:	      temp.setclass(tokenclass(2));
		      temp.setvalue(0);
		      ilist.enterinst(111,temp);                    //LDA# 0
		      opcode=460;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //CPA
		      curinstnum=instnum+2;
		      temp.setclass(tokenclass(2));
		      temp.setvalue(curinstnum+2);
		      ilist.enterinst(850,temp);                    //JNE
		      temp.setclass(tokenclass(2));
		      temp.setvalue(1);
		      ilist.enterinst(111,temp);                    //LDA# 1
		      opcode=160;
		      temp.setclass(tokenclass(4));
		      temp.setvalue(quad.result);
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //STA
		      instnum+=5;
		      break;
      case odd:       opcode=110;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //LDA
		      temp.setclass(tokenclass(2));
		      temp.setvalue(2);
		      ilist.enterinst(411,temp);                    //MDA# 2
		      opcode=160;
		      temp.setclass(tokenclass(4));
		      temp.setvalue(quad.result);
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //STA
		      instnum+=3;
		      break;
      case B:         if (quad.result!=ilist.quadnumber()+1) {
			temp.setvalue(0);
			ilist.enterinst(800,temp);                  //JMP
			instnum+=1;
		      };
		      break;
      case BF:        opcode=110;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //LDA
		      temp.setclass(tokenclass(2));
		      temp.setvalue(0);
		      ilist.enterinst(461,temp);                    //CPA# 0
		      temp.setvalue(quad.result);
		      ilist.enterinst(820,temp);                    //JEQ
		      instnum+=3;
		      break;
      case JSR:       temp.setvalue(0);
		      ilist.enterinst(870,temp);                    //JSR
		      instnum+=1;
		      break;
      case RTN:       temp.setvalue(0);
		      ilist.enterinst(900,temp);                    //RTN
		      instnum+=1;
		      break;
      case ASP:       if (quad.opnd1.getvalue()!=0) {
			ilist.enterinst(651,quad.opnd1);            //ASP
			instnum+=1;
		      };
		      break;
      case FSP:       if (quad.opnd1.getvalue()!=0) {
			ilist.enterinst(661,quad.opnd1);            //FSP
			instnum+=1;
		      };
		      break;
      case PSH:       opcode=600;
		      setaddrmode(opcode,quad.opnd1);
		      ilist.enterinst(opcode,quad.opnd1);           //PSH
		      instnum+=1;
		      break;
      case POP:       opcode=610;
		      temp.setclass(tokenclass(1));
		      temp.setvalue(quad.result);
		      setaddrmode(opcode,temp);
		      ilist.enterinst(opcode,temp);                 //POP
		      instnum+=1;
		      break;
      case haltop:    temp.setvalue(0);
		      ilist.enterinst(990,temp);                    //HLT
		      instnum+=1;
		      endcodegeneration=TRUE;
		      break;
      default:        cout<<"\nUnidentified Quadruple!\n\n";
		      exit(1);
    };
  };
  ilist.repairjumps();
  qf.closequadfile();
  cf.createcodefile();
  emitallinsts();
  cf.closecodefile();
};