r_mod.c   [plain text]

#include "f2c.h"

#ifdef IEEE_drem
double drem (double, double);
#else
#undef abs
#include <math.h>
#endif
double
r_mod (real * x, real * y)
{
#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
}