Which version of OCaml? The ARMv7 backend was rewritten about 2 years ago, and merged in 4.00.

http://caml.inria.fr/mantis/view.php?id=5433

The new backend is supposed to be considerably faster on floating point code. This code looks integer only, and I don't have relative performance of old/new backend for integer code.

As a wider question: Who cares much about ARMv7? ARMv8 is a completely different beast, requiring a different backend, with much better raw performance (on the same terms as x86-64). That's where languages should be concentrating their current efforts.