/* According to IEEE 754-2008 section 3.4, for the w-bit exponent:
 * "The range of the encoding’s biased exponent E shall include:
 *  ― every integer between 1 and 2**w − 2, inclusive, to encode normal numbers
 *  ― the reserved value 0 to encode ±0 and subnormal numbers
 *  ― the reserved value 2**w − 1 to encode ±∞ and NaNs."  */
if(exp == 0)  {			/* exp==0:  0 or subnormal */
    /* 0 done above, so must be subnormal */
    puts("subnormal"); /* QQ */
    return(FP_SUBNORMAL);
    }
  else if(exp < exp_mask)  {	/* exp 1 to 2**w-2:  normal */
    puts("normal"); /* QQ */
    return(FP_NORMAL);
    }
  else {			/* exp==2**w-1:  ±∞ or ±NaN */