$ cat main.c
#include <stdio.h>
#include <time.h>

int main() {
  struct timespec ts;

  for (int i = 0; i < 100; ++i) {
    clock_gettime(CLOCK_MONOTONIC_COARSE, &ts);
    printf("%d %ld\n", ts.tv_sec, ts.tv_nsec);
  }
  return 0;
}

$ cc -m32 main.c
$ ./a.out
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
-1 318747501
....


This happens when building the program as 32bit executable on 64bit FreeBSD and run the executable on 64bit FreeBSD.