Authentification du mot de passe

<?php
 session_start();
  $email=$_POST['email'];
  $pass=$_POST['password'];
 if(isset($_POST['submit']))
 {
  $bd = new PDO('mysql:host=localhost;dbname=loginsystem', 'root', '');
  
  $sql="SELECT * FROM users where email='$email'AND password='$pass' ";
  $result=$bd->prepare($sql);
  $result->execute();
  if (!$result)
  {
   echo "mot de passe incorrect";
  }
  else{
   echo "Bienvenu";
  }
  else
   {
    $pass=password_hash($pass,PASSWORD_DEFAULT);
    $sql="INSERT INTO users(email, password)VALUES('$email','$pass')";
    $req=$bd->prepare($sql);
    $req->execute();
    echo "Enregistrement réussie";
    
    
   }
 }
?>