the ordinary function do a lot of activity store the argument into stack saving register
control goes to the function and return value to the calling function but in inline
function body replace to the calling the function (like as macro expansion)
it is reqest to the compiler not a command compiler may ignore the request if
function is so length

In case of ordinary function when calling the function the scope jumps to the function and after return jumps back to the function call statement resulting in some extra execution time. While in case of inline function the scope doesn't really jumps to the function saving some execution time. However while making any function inline we are just sending request to make the function inline it completely depends on the compiler that it will treat the function as inline or some ordinary function.