According to Jane Street's article ( http://www.haskell.org/sitewiki/images/0/03/TMR-Issue7.pdf http://www.haskell.org/sitewiki/images/0/03/TMR-Issue7.pdf , pag

According to Jane Street's article ( http://www.haskell.org/sitewiki/images/0/03/TMR-Issue7.pdf http://www.haskell.org/sitewiki/images/0/03/TMR-Issue7.pdf , page 23 ) the ocaml compiler doesnt really do much optimisation at all. The performance comes down to data representation, gc and native code generation. This has the nice side effect of making it really easy to reason about the performance of ocaml code, at the cost of wasted optimisation opportunities.