#include "f2c.h"

#ifdef KR_headers
#ifdef IEEE_drem
double drem();
#else
double floor();
#endif
double r_mod(x, y) real *x, *y;
#else
#ifdef IEEE_drem
double drem(double, double);
#else
#undef abs
#include "math.h"
#endif
double r_mod(real *x, real *y)
#endif
{
#ifdef IEEE_drem
  double xa, ya, z;
  if((ya = *y) < 0.)
    ya = -ya;
  z = drem(xa = *x, ya);
  if(xa > 0)
  {
    if(z < 0)
      z += ya;
  }
  else if(z > 0)
    z -= ya;
  return z;
#else
  double quotient;
  if((quotient = (double) * x / *y) >= 0)
    quotient = floor(quotient);
  else
    quotient = -floor(-quotient);
  return(*x - (*y) * quotient);
#endif
}
