CHECK_C_SOURCE_COMPILES("
#include <sys/types.h>
#include <sys/syscall.h>
#include <unistd.h>
int main(int ac, char **av)
{
  unsigned long long tid = syscall(SYS_thread_selfid);
  return (tid != 0 ? 0 : 1);
}"
HAVE_SYS_THREAD_SELFID)