C-based MIPS Simulator na di gumagana

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

int32_t signext(int32_t immediate) // sign-extend
{
    int32_t value = (0x0000FFFF & immediate);
    if (0x00008000 & immediate)
    {
        value |= 0xFFFF0000;
    }
    return value;
}

int main()
{
    // components of Processor
   int N;
   scanf("%d",&N);
   int32_t imem[N];
   int32_t regfile[32] = {0};
   int32_t dmem[1000] = {0};

    // get instructions put em into imem
    for(int i = 0;i<N;i++)
    {
        scanf("%d",&imem[i]);
    }

    int PC = 0;

    while(PC != N)
    {
        printf("PC: %d\n",PC);
        // fetch instruction
        int32_t instr = imem[PC];
        uint32_t opcode, rs, rt, rd, funct, jta;
        int32_t immediate;
        opcode = instr >> 26;
        rs = (instr << 6) >> 27;
        rt = (instr << 11) >> 27;
        rd = (instr << 16) >> 27;
        funct = (instr << 26) >> 26;
        immediate = signext((instr << 16) >> 16);
        jta = (instr << 6) >> 6;

        if(opcode == 0) // R-type
        {
            if(funct == 0x20) // add
            {
                if(rd != 0)
                {
                    regfile[rd] = regfile[rs] + regfile[rt];
                }
                PC++;
                continue;
            }
            else if(funct == 0x22) // sub
            {
                if(rd != 0)
                {
                    regfile[rd] = regfile[rs] - regfile[rt];

                }
                PC++;
                continue;
            }
            else if(funct == 0x24) // and
            {
                if(rd != 0)
                {
                    regfile[rd] = regfile[rs] & regfile[rt];
                }
                PC++;
                continue;

            }
            else if(funct == 0x25) // or
            {
                if(rd != 0)
                {
                    regfile[rd] = regfile[rs] | regfile[rt];
                }
                PC++;
                continue;
            }
            else if(funct == 0x2a) // slt
            {
               if(rd != 0)
                {
                    regfile[rd] = (regfile[rs] < regfile[rt])? 1 : 0;
                }
                PC++;
                continue;

            }
            else if(funct == 0xc) // syscall
            {
                if(regfile[2] == 34)
                {
                    printf("0x%8X\n",regfile[4]);
                    PC++;
                }
                else if(regfile[2] == 10)
                {
                    PC = N;
                }
                continue;
            }

        }
        else if(opcode == 0x9) // addiu
        {
            if(rt != 0)
            {
                regfile[rt] = regfile[rs] + immediate;
            }
            PC++;
            continue;

        }
        else if(opcode == 0x4) // beq
        {
            if(regfile[rs] == regfile[rt])
            {
                PC = PC + 1 + immediate;
            }
            else
            {
                PC++;
            }
            continue;
        }
        else if(opcode == 0x23) // lw
        {
            if(rt != 0)
            {
                regfile[rt] = dmem[regfile[rs] + immediate];
            }
            PC++;
            continue;
        }
        else if(opcode == 0x2b)
        {
            dmem[regfile[rs] + immediate] = regfile[rt];
            PC++;
            continue;
        }
        else if(opcode == 0x2)
        {
            PC = jta;
            continue;
        }
    }
}