+static void
+usage (void)
+{
+ printf ("usage: insn-reverse <0-%d>\n", n_testcases - 1);
+}
+
+static int test_nr;
+
+static void
+parse_args (int argc, char **argv)
+{
+ if (argc != 2)
+ {
+ usage ();
+ exit (1);
+ }
+
+ char *tail;
+ test_nr = strtol (argv[1], &tail, 10);
+ if (*tail != '\0')
+ {
+ usage ();
+ exit (1);
+ }
+
+ int in_range_p = 0 <= test_nr && test_nr < n_testcases;
+ if (!in_range_p)
+ {
+ usage ();
+ exit (1);
+ }
+}
+