#include <sys/ioctl.h>
#include <sys/param.h>
#include <sys/module.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include <sys/cpuctl.h>
#include <cpuid.h>

int main(int argc, char* argv[])
{
  char module[] = "cpuctl";
  char* msg[] = { "no", "yes" };
  cpuctl_cpuid_count_args_t args;
  int fd, error, sse42;

  if (geteuid() == 0 && modfind(module) < 0)
    if (kldload(module) < 0 || modfind(module) < 0)
      err(1, "%s", module);

  args.level = 1;
  args.level_type = 0;
  fd = open("/dev/cpuctl0", O_RDONLY);
  if (fd < 0)
      err(1, "could not open /dev/cpuctl0 (need kmem group at least)");
  error = ioctl(fd, CPUCTL_CPUID_COUNT, &args);
  if (error < 0)
     err(1, "ioctl(CPUCTL_CPUID_COUNT)");
  sse42 = (args.data[2] & bit_SSE42) != 0;
  fprintf(stdout, "SSE4.2 support: %s\n", msg[sse42]);
  close(fd);
  return (0);
}