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Question about float refs.

Ethan Burns
- Lukasz Stafiniak
- David House
  - Till Varoquaux
- Christophe TROESTLER
  - Ethan Burns
    - Sylvain Le Gall
      - Dmitry Bely
        
        Jon Harrop
        
        Dmitry Bely
        
        Christophe TROESTLER
        
        Fabrice Le Fessant
        
        Ethan Burns
        
        Fabrice Le Fessant

Date:	-- (:)
From:	Christophe TROESTLER <Christophe.Troestler+ocaml@u...>
Subject:	Re: [Caml-list] Re: Question about float refs.

On Wed, 1 Sep 2010 11:18:05 +0400, Dmitry Bely wrote:
> 
> >> Some black magic is needed:
> >>
> >> let r = ref 0.0 in
> >> for i = 0 to 1000_000_000 do r := float i done;
> >> Printf.printf "%f\n" (!r +. 0.);
> >> Printf.printf "words: %f\n" (Gc.stat ()).Gc.minor_words
> 
> Do you have any idea why the optimizer needs that?

It helps the compiler to figure out that $B!H(Br$B!I(B must be unboxed.
See also http://caml.inria.fr/mantis/view.php?id=5133

C.