Thank you all for your answers.

I used this floating point converter to generate my numbers: http://babbage.cs.qc.edu/IEEE-754/

I simply reversed the characters in "Merry Ch" and "ristmas!" and fed the hex equivalents into the converter. However, I had to adjust them a bit to make the script actually print Merry Christmas!.

Now if we assume the converter to be conformant to IEEE-754, then it follows that your Perl (or compiler or OS) is not conformant, if it prints "Merry Christmas!" Even if it is a small difference numerically, it is a difference.

Anyway, I wish you all a merry Christmas, regardless the correctness of your floating point library. :)