 pointless.  A single float format detector macro could look at
     <code>double</code> then <code>long double</code>
     <br>
     Sometimes there's a compiler option for the size of a <code>long
     double</code>, eg. xlc on AIX can use either 64-bit or 128-bit.  It's
     probably simplest to regard this as a compiler compatibility issue, and
     leave it to users or sysadmins to ensure application and library code is
     built the same.
<li> <code>mpz_sqrt_if_perfect_square</code>: When
     <code>