Local vars in gcc assembly

When I compile the function below: gcc -S teste.c

void readInput() {
    int buf;
}

teste.S becomes:

readInput:
     pushl   %ebp
     movl    %esp, %ebp
     subl    $16, %esp
     leave
     ret

My doubt is: why is% esp subtracted from 16 bytes, shouldn't it be 4 bytes for int? Does he have a todo with alignment?

Similar things happen when I compile this:

void readInput() {
    char buf;
}

and the output is the same as above.