#include "libm.h"

double trunc(double x) {
  union {
    double f;
    uint64_t i;
  } u = {x};
  int e = (int)(u.i >> 52 & 0x7ff) - 0x3ff + 12;
  uint64_t m;

  if (e >= 52 + 12)
    return x;
  if (e < 12)
    e = 1;
  m = -1ULL >> e;
  if ((u.i & m) == 0)
    return x;
  FORCE_EVAL(x + 0x1p120f);
  u.i &= ~m;
  return u.f;
}