lab-04-Rushilwiz/lab04.c

// PID: 730677144
// I pledge the COMP 211 honor code.

#include <limits.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

#include "instructions.h"

#define REGISTER_SIZE 32

void execute_r_instruction(r_instruction* instruct);
void execute_i_instruction(i_instruction* instruct);

static uint16_t registers[REGISTER_SIZE] = {0};

int main() {
    uint32_t instruct;

    while (true) {
        printf("Please enter your instruction as a 32-bit integer: ");

        if (scanf("%u", &instruct) != 1) {
            printf("\n");
            fprintf(stderr, "Failed to read instruction!\n");
            return EXIT_FAILURE;
        }

        if (instruct == UINT_MAX)
            return EXIT_SUCCESS;

        if (get_type_of_instruction(instruct) == R_TYPE) {
            r_instruction* r_instruct = create_r_instruction(instruct);
            execute_r_instruction(r_instruct);
            free(r_instruct);
        } else {  // I_TYPE
            i_instruction* i_instruct = create_i_instruction(instruct);
            execute_i_instruction(i_instruct);
            free(i_instruct);
        }

        printf("Current register status:\n");

        printf("[");

        for (int i = 0; i < REGISTER_SIZE; i++) {
            printf("%d", registers[i]);

            if (i != REGISTER_SIZE - 1)
                printf(", ");
        }

        printf("]\n");
    }
}

// ------------------------------------
// Takes the r_instruction
// you created in Part 1 and, based on the MIPS instruction,
// performs the operation and updates the 'registers' array
// (see top of file).
//
// Hint: the "func" bits determine the operation (i.e., SLL,
// SRA, ADD, SUB, AND, OR).
//
// Arguments:   r_instruction structure
//
// Return:      None
//
void execute_r_instruction(r_instruction* instruct) {
    switch (instruct->func) {
        case SLL_FUNC:
            registers[instruct->rd] = registers[instruct->rt]
                                      << instruct->shamt;
            break;
        case SRA_FUNC:
            registers[instruct->rd] =
                registers[instruct->rt] >> instruct->shamt;
            break;
        case ADD_FUNC:
            registers[instruct->rd] =
                registers[instruct->rs] + registers[instruct->rt];
            break;
        case SUB_FUNC:
            registers[instruct->rd] =
                registers[instruct->rs] - registers[instruct->rt];
            break;
        case AND_FUNC:
            registers[instruct->rd] =
                registers[instruct->rs] & registers[instruct->rt];
            break;
        case OR_FUNC:
            registers[instruct->rd] =
                registers[instruct->rs] | registers[instruct->rt];
            break;
        case NOR_FUNC:
            registers[instruct->rd] =
                ~(registers[instruct->rs] | registers[instruct->rt]);
            break;
        default:
            fprintf(stderr, "Invalid function code!\n");
            exit(EXIT_FAILURE);
    }

}  // end execute_r_instruction() function

// ------------------------------------
// Takes the i_instruction
// you created in Part 1 and, based on the MIPS instruction,
// performs the operation and updates the 'registers' array
// (see top of file).
//
// Hint: the "opcode" bits determine the operation (.e.,  ADDI,
// ANDI, ORI).
//
// Arguments:   i_instruction structure
//
// Return:      None
//
void execute_i_instruction(i_instruction* instruct) {
    switch (instruct->opcode) {
        case ADDI_OPCODE:
            registers[instruct->rt] =
                registers[instruct->rs] + instruct->immediate;
            break;
        case ANDI_OPCODE:
            registers[instruct->rt] =
                registers[instruct->rs] & instruct->immediate;
            break;
        case ORI_OPCODE:
            registers[instruct->rt] =
                registers[instruct->rs] | instruct->immediate;
            break;
        default:
            fprintf(stderr, "Invalid opcode!\n");
            exit(EXIT_FAILURE);
    }
}  // end execute_i_instruction() function