From: Dmitry Bely <dmitry.bely@gmail.com>
To: caml-list@inria.fr
Subject: Re: [Caml-list] Re: Question about float refs.
Date: Wed, 1 Sep 2010 11:18:05 +0400 [thread overview]
Message-ID: <AANLkTimWwzasrCYA2FHg+Kn_CN_yLBerWRDsSyqBrYgT@mail.gmail.com> (raw)
In-Reply-To: <031b01cb4944$77110900$65331b00$@com>
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
next prev parent reply other threads:[~2010-09-01 7:18 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-08-19 11:52 Ethan Burns
2010-08-19 13:14 ` [Caml-list] " Lukasz Stafiniak
2010-08-19 13:34 ` David House
2010-08-19 13:49 ` Till Varoquaux
2010-08-23 12:06 ` Christophe TROESTLER
2010-08-23 12:14 ` Ethan Burns
2010-08-23 12:42 ` Sylvain Le Gall
2010-08-23 13:00 ` [Caml-list] " Dmitry Bely
2010-08-31 19:41 ` Jon Harrop
2010-09-01 7:18 ` Dmitry Bely [this message]
2010-09-01 7:46 ` Christophe TROESTLER
2010-09-01 8:31 ` Fabrice Le Fessant
2010-09-01 9:54 ` Ethan Burns
2010-09-01 12:29 ` Fabrice Le Fessant
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