#! perl -slw
use strict;

sub myExp{
    my $e = 1 + ( shift() / 4294967296 );
    $e *= $e for 1 .. 32;
    $e;
}

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

__END__

C:\test>exp 
       9.9999999999999965e-011 :        1.0000000285332257e-010
       1.0000000000000007e-009 :        1.0000000829163549e-009
        9.999999999999982e-009 :        1.0000002130576865e-008
       9.9999999999999943e-008 :        9.9999976329917627e-008
       1.0000000000000004e-006 :        9.9999969112813618e-007
       9.9999999999999974e-006 :        9.9999977582604716e-006
        0.00010000000000000009 :         9.999998681099902e-005
         0.0010000000000000002 :         0.00099999984556405617
          0.010000000000000005 :          0.0099999993405499293
           0.10000000000000002 :           0.099999996702749588
                             1 :                              1
            10.000000000000002 :             9.9999952742988558
            100.00000000000004 :             100.00000084944983
            999.99999999999977 :             999.99959325720954
            10000.000000000009 :             10000.000169889967
            100000.00000000001 :             99999.966690555739
            999999.99999999953 :             1000000.1401405634
            10000000.000000006 :             9999996.1589527112
            100000000.00000018 :             100000003.39779937
            999999999.99999928 :             999999662.81900096
            10000000000.000004 :             10000002874.419859