GLIB：g_atomic_int_get变为NO-OP？

#include <stdlib.h>
#include "glib.h"
#include "pthread.h"
#include "stdio.h"

void *set_foo(void *ptr) {
  g_atomic_int_set(((int*)ptr), 42);
  return NULL;
}

int main(void) {
  int foo = 0;
  pthread_t other;

  if (pthread_create(&other, NULL, set_foo, &foo)== 0) {
    pthread_join(other, NULL);
    printf("Got %dn", g_atomic_int_get(&foo));
  } else {
    printf("Thread did not runn");
    exit(1);
  }
}

(*(&foo))

((void) (*(((int*)ptr)) = (42)))

gcc -m64 -E -o foo.E `pkg-config --cflags glib-2.0` -O0 -g foo.c