#include "libm.h"

#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024
long double modfl(long double x, long double* iptr) {
  double d;
  long double r;

  r = modf(x, &d);
  *iptr = d;
  return r;
}
#elif (LDBL_MANT_DIG == 64 || LDBL_MANT_DIG == 113) && LDBL_MAX_EXP == 16384

static const long double toint = 1 / LDBL_EPSILON;

long double modfl(long double x, long double* iptr) {
  union ldshape u = {x};
  int e = (u.i.se & 0x7fff) - 0x3fff;
  int s = u.i.se >> 15;
  long double absx;
  long double y;

  /* no fractional part */
  if (e >= LDBL_MANT_DIG - 1) {
    *iptr = x;
    if (isnan(x))
      return x;
    return s ? -0.0 : 0.0;
  }

  /* no integral part*/
  if (e < 0) {
    *iptr = s ? -0.0 : 0.0;
    return x;
  }

  /* raises spurious inexact */
  absx = s ? -x : x;
  y = absx + toint - toint - absx;
  if (y == 0) {
    *iptr = x;
    return s ? -0.0 : 0.0;
  }
  if (y > 0)
    y -= 1;
  if (s)
    y = -y;
  *iptr = x + y;
  return -y;
}
#endif