#! perl -slw
use strict;

sub myExp{
    my $e = 1 + ( shift() / 10000000 );
    my $r = $e;
    $r *= $e for 2 .. 10000000;
    $r;
}

printf "%30.20g : %30.20g\n", exp( $_ ), myExp( $_ )
    for map log( 10**$_ ), -10 .. 10;

__END__
C:\test>exp
       9.9999999999999965e-011 :        9.9997349036884958e-011
       1.0000000000000007e-009 :        9.9997852777366009e-010
        9.999999999999982e-009 :        9.9998303391048947e-009
       9.9999999999999943e-008 :        9.9998700988200641e-008
       1.0000000000000004e-006 :        9.9999045679358269e-007
       9.9999999999999974e-006 :        9.9999337241854084e-006
        0.00010000000000000009 :        9.9999575897369183e-005
         0.0010000000000000002 :         0.00099999761423453593
          0.010000000000000005 :          0.0099999893930861859
           0.10000000000000002 :           0.099999973530420908
                             1 :                              1
            10.000000000000002 :             9.9999973561653093
            100.00000000000004 :             99.999893882330838
            999.99999999999977 :             999.99761406302275
            10000.000000000009 :             9999.9575911775646
            100000.00000000001 :             99999.337176962814
            999999.99999999953 :             999990.45646420098
            10000000.000000006 :             9999870.1098560225
            100000000.00000018 :             99998303.311974689
            999999999.99999928 :             999978527.31280696
            10000000000.000004 :             9999734913.5273266