#include <stddef.h>
#include <float.h>

#define SIMD_SIZE 8

inline double sqr(double x)
{
    return x*x;
}

size_t foo(double tourx[], double toury[], size_t ncities, double ThisX, double ThisY, double *cd)
{
  size_t j;
  double CloseDist = *cd;
  double ThisDist;
  
  j=ncities-1;
  do {
      ThisDist = sqr(tourx[j]-ThisX)+sqr(toury[j]-ThisY);
      j--;
  } while (ThisDist <= CloseDist);
  *cd = ThisDist;
  return j;
}