#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>

void hpcwall(double *retval)
{
  static long zsec = 0;
  static long zusec = 0;
  double esec;
  struct timeval tp;
  struct timezone tzp;
 
  gettimeofday(&tp, &tzp);
 
  if ( zsec == 0 ) zsec = tp.tv_sec;
  if ( zusec == 0 ) zusec = tp.tv_usec;
 
  *retval = (tp.tv_sec - zsec) + (tp.tv_usec - zusec ) * 0.000001 ;
}

void hpcwall_(double *retval) { hpcwall(retval); } /* Other convention */