ocaml-native-compilers binary package in Ubuntu Xenial i386

 Objective Caml (OCaml) is an implementation of the ML language, based on
 the Caml Light dialect extended with a complete class-based object system
 and a powerful module system in the style of Standard ML.
 .
 This package contains the native code version of the compilers
 (ocamlc.opt, ocamllex.opt, ocamlopt.opt. The normal version of these
 programs are found in the 'ocaml' package. For big source codes,
 these packages can be two to three times faster, but for most normal
 sized sources, the difference won't be noticeable.

Source package