unsigned int2hfloat(int x)
{
  unsigned sign = x < 0;
  unsigned absx = ((unsigned)x ^ -sign) + sign; // safe abs(x)
  unsigned tmp = absx, manbits = 0;
  int exp = 0, truncated = 0;

  // calculate the number of bits needed for the mantissa
  while (tmp)
  {
    tmp >>= 1;
    manbits++;
  }

  // half-precision floats have 11 bits in the mantissa.
  // truncate the excess or insert the lacking 0s until there are 11.
  if (manbits)
  {
    exp = 10; // exp bias because 1.0 is at bit position 10
    while (manbits > 11)
    {
      truncated |= absx & 1;
      absx >>= 1;
      manbits--;
      exp++;
    }
    while (manbits < 11)
    {
      absx <<= 1;
      manbits++;
      exp--;
    }
  }

  if (exp + truncated > 15)
  {
    // absx was too big, force it to +/- infinity
    exp = 31; // special infinity value
    absx = 0;
  }
  else if (manbits)
  {
    // normal case, absx > 0
    exp += 15; // bias the exponent
  }

  return (sign << 15) | ((unsigned)exp << 10) | (absx & ((1u<<10)-1));
}