trying to find out if ruby 1.9.2 does not implement syscall() on amd64 because of the different sizes if int and long

sizeof64.c

/*
  please do me a favour: do the following on a amd64 ubuntu

  $ gcc -o sizeof64 sizeof64.c
  $ ./sizeof64

  are they different? would this be OK? If not, what could cause this?
  If it is OK, why is ruby 1.9 not able to implement syscall()

  https://github.com/ruby/ruby/blob/ruby_1_9_2/io.c#L7529
 
  It's long time since I coded C so please forgive my missing -wall

*/

#include <stdio.h>

main() {
        static int an_int = 23;
        static long a_long = 23;

        printf("size of int: %i\n", (int) sizeof((an_int)) );
        printf("size of long: %i\n", (int) sizeof((a_long)) );
}

martin@neolith:/tmp$ ./sizeof64
size of int: 4
size of long: 8