1367 sub _log_int
   1368   {
   1369   # calculate integer log of $x to base $base
   1370   # ref to array, ref to array - return ref to array
   1371   my ($c,$x,$base) = @_;
   1372
   1373   # X == 0 => NaN
   1374   return if (scalar @$x == 1 && $x->[0] == 0);
   1375   # BASE 0 or 1 => NaN
   1376   return if (scalar @$base == 1 && $base->[0] < 2);
   1377   my $cmp = _acmp($c,$x,$base); # X == BASE => 1
   1378   if ($cmp == 0)
   1379     {
   1380     splice (@$x,1); $x->[0] = 1;
   1381     return ($x,1)
   1382     }
   1383   # X < BASE
   1384   if ($cmp < 0)
   1385     {
   1386     splice (@$x,1); $x->[0] = 0;
   1387     return ($x,undef);
   1388     }
   1389