codegen.c

#include "codegen.h"
#include "symtab.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

extern FILE *output;
int free_reg_num = 0;
char invalid_value[] = "???";

// REGISTERS

int take_reg(void) {
	if(free_reg_num > LAST_WORKING_REG) {
		err("Compiler error! No free registers!");
		exit(EXIT_FAILURE);
	}
	return free_reg_num++;
}

void free_reg(void) {
	if(free_reg_num < 1) {
		err("Compiler error! No more registers to free!");
		exit(EXIT_FAILURE);
	} else
		set_type(--free_reg_num, NO_TYPE);
}

// Ako je u pitanju indeks registra, oslobodi registar NA VRHU STEKA!
void free_if_reg(int reg_index) {
	if(reg_index >= 0 && reg_index <= LAST_WORKING_REG)
		free_reg();
}

// SYMBOL
// Izmenjeno da vraca string umesto void
void gen_sym_name(int index) {
	if(index > -1) {
		if(get_kind(index) == VAR) { // -n*4(%14)
			code("-%d(%%14)", get_atr1(index) * 4);
		} else if(get_kind(index) == PAR) { // m*4(%14)
			code("%d(%%14)", 4 + get_atr1(index) * 4);
		} else if(get_kind(index) == LIT) {
			code("$%s", get_name(index));
		} else { //function, reg, gvar
			code("%s", get_name(index));
		}
	}
}

// Dodato
char *print_sym_name(int index) {
	if(index > -1) {
		if(get_kind(index) == VAR) { // -n*4(%14)
			//code("-%d(%%14)", get_atr1(index) * 4);
			// Dodato : (Ali je nepotrebno)
			static char ret[10];
			strcpy(ret, "-");
			char ind[4];
			sprintf(ind, "%d", get_atr1(index) * 4);
			strcat(ret, ind);
			strcat(ret, "(%14)");
			return ret;
		} else if(get_kind(index) == PAR) { // m*4(%14)
			//code("%d(%%14)", 4 + get_atr1(index) * 4);
			// TODO:
		} else if(get_kind(index) == LIT) {
			//code("$%s", get_name(index));
			// TODO:
		} else { //function, reg, gvar
			return get_name(index);
		}
	}
}

// OTHER

void gen_cmp(int op1_index, int op2_index) {
	if(get_type(op1_index) == INT)
		code("\n\t\tCMPS \t");
	else
		code("\n\t\tCMPU \t");
	gen_sym_name(op1_index);
	code(",");
	gen_sym_name(op2_index);
	free_if_reg(op2_index);
	free_if_reg(op1_index);
}

void gen_mov(int input_index, int output_index) {
	code("\n\t\tMOV \t");
	gen_sym_name(input_index);
	code(",");
	gen_sym_name(output_index);

	//ako se smešta u registar, treba preneti tip
	if(output_index >= 0 && output_index <= LAST_WORKING_REG)
		set_type(output_index, get_type(input_index));
	free_if_reg(input_index);
}