/*
 *********************************************
 *  314 Principles of Programming Languages  *
 *  Fall 2016                              *
 *********************************************
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include "InstrUtils.h"
#include "Utils.h"

void optimizer(Instruction* ptr, int field);

int main()
{
	Instruction *head;

	head = ReadInstructionList(stdin);
	if (!head) {
		WARNING("No instructions\n");
		exit(EXIT_FAILURE);
	}
	/* YOUR CODE GOES HERE */

	Instruction* curr = head;
	Instruction* ptr = head;

	/*
	while(curr != NULL){
		curr = curr -> next;
	}
	*/
		optimizer(curr, curr -> field1);
		optimizer(curr, curr -> field2);
		optimizer(curr, curr -> field3);

	//iterative method
	/*

	Instruction* instr1;
	Instruction* instr2;
	Instruction* instr3;

	instr1 = head;
	instr2 = head -> next;
	instr3 = head -> next -> next;

	while(instr3){


        if(instr1 -> opcode == LOADI && instr2 -> opcode == LOADI){

			switch(instr3 -> opcode){

				//missing load statement
				case LOADI:
					if(instr3 -> field1 != instr2 -> field1 && instr3 -> field1 != instr1 -> field1){
						printf("FATAL ERROR");
						exit(EXIT_FAILURE);
						break;
					}
				case STORE:

				default:
					break;
			}
		}

		instr1 = instr2;
		instr2 = instr3;
		instr3 = instr3 -> next;
	}
	*/

	while(ptr){

		if(ptr -> critical == 'y'){

			PrintInstruction(stdout, ptr);
		}
		ptr = ptr -> next;
	}


	//DestroyInstructionList(head);
	return EXIT_SUCCESS;
}

void optimizer(Instruction* ptr, int field){

	if(ptr == NULL) return;

	if(ptr -> field1 == field || ptr -> field2 == field || ptr -> field3 == field){

		ptr -> critical = 'y';

		optimizer (ptr->next, ptr->field1);
		optimizer (ptr->next, ptr->field2);
		optimizer (ptr->next, ptr->field3);
		}
}