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Date: Wed, 1 Sep 2010 11:18:05 +0400
Message-ID: <AANLkTimWwzasrCYA2FHg+Kn_CN_yLBerWRDsSyqBrYgT@mail.gmail.com>
Subject: Re: [Caml-list] Re: Question about float refs.
From: Dmitry Bely <dmitry.bely@gmail.com>
To: caml-list@inria.fr
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X-Spam: no; 0.00; cheers:01 printf:01 printf:01 1.0:98 wrote:01 heap:01 dmitry:01 dmitry:01 caml-list:01 minor:01 bely:01 bely:01 caml:02 black:96 float:03 

On Tue, Aug 31, 2010 at 11:41 PM, Jon Harrop
<jonathandeanharrop@googlemail.com> wrote:

> You might prefer to multiply by 1.0 because adding 0.0 changes -0.0.
>
> Cheers,
> Jon.
>
>> 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
>>
>> and the reference will be placed in a register (Caml heap will not be
>> used inside the loop)

Do you have any idea why the optimizer needs that?

- Dmitry Bely