From: "Alejandro R. Mosteo" <alejandro@mosteo.com>
Subject: Re: Everything You Know Is Wrong
Date: Mon, 4 Jan 2016 15:51:56 +0100
Date: 2016-01-04T15:51:56+01:00 [thread overview]
Message-ID: <n6e0pd$561$1@dont-email.me> (raw)
In-Reply-To: <n5uh6q$chh$1@dont-email.me>
On 29/12/15 18:53, G.B. wrote:
> On 29.12.15 18:36, Dmitry A. Kazakov wrote:
>> On 2015-12-29 17:57, G.B. wrote:
>>
>>> The point is that, since order does not matter among these parallel
>>> computations, and since parallel loops are not just fantasy,
>>> the possibility of postponement follows from parallel loops.
>>
>> Ada does not have parallel loops.
>
> Ada is about to have parallel loops. Ada compilers already produce
> code for parallel execution of loop bodies on today's processors.
In this regard, just the other day I discovered Matlab's parfor, which
as expected just parallelizes what would be a plain loop. It even emits
some warnings about how the input data should be structured/used to
minimize data transmission to the workers (which may be remote). I guess
it would be interesting to look at how this and other languages do it.
-Álex.
>
>
>>> Consider F1 and F2 from a Pure package, X a variable of type T
>>> and T without progenitors:
>>>
>>> declare
>>> A : T := F1 (1,2,3);
>>> B : T := F2 (X);
>>> begin
>>> G (A, B);
>>> end;
>>>
>>> Is it impossible for a compiler to see that the initializing parts of
>>> the declarations of A and B are independent?
>>
>> No, because initialization of T may have side effects.
>
> I assume you meant Yes, impossible. But,
> if F1 and F2 are from a Pure package, is the compiler allowed to
> ignore side effects because the programmer specified Pure? I think
> that follows.
>
>> BTW, why do you believe that the same amount of computation performed
>> consecutively should require less energy or (not quite same) less
>> battery drain?
>
> Less energy at a certain point in time. Postpone calling sub if, say,
> a photocell should first be given time to recharge a battery while
> while regular operation continues, then call sub.
>
>
next prev parent reply other threads:[~2016-01-04 14:51 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-27 0:37 Everything You Know Is Wrong Jeffrey R. Carter
2015-12-27 7:55 ` J-P. Rosen
2015-12-27 17:37 ` Jeffrey R. Carter
2015-12-27 8:46 ` Dmitry A. Kazakov
2015-12-27 17:36 ` Jeffrey R. Carter
2016-01-04 14:44 ` Alejandro R. Mosteo
2015-12-28 9:57 ` Georg Bauhaus
2015-12-28 11:19 ` Dmitry A. Kazakov
2015-12-28 16:27 ` Nicholas Collin Paul de Gloucester
2015-12-28 17:30 ` Dmitry A. Kazakov
2015-12-28 18:50 ` Nicholas Collin Paul de Gloucester
2015-12-28 20:40 ` Dmitry A. Kazakov
2015-12-29 11:42 ` G.B.
2015-12-29 12:36 ` Dmitry A. Kazakov
2015-12-29 13:50 ` G.B.
2015-12-29 14:06 ` J-P. Rosen
2015-12-29 14:16 ` Dmitry A. Kazakov
2015-12-29 16:31 ` Dennis Lee Bieber
2015-12-29 17:02 ` G.B.
2015-12-29 16:57 ` G.B.
2015-12-29 17:36 ` Dmitry A. Kazakov
2015-12-29 17:53 ` G.B.
2015-12-29 18:09 ` G.B.
2015-12-29 22:05 ` Randy Brukardt
2016-01-04 14:51 ` Alejandro R. Mosteo [this message]
2015-12-29 21:58 ` Randy Brukardt
2015-12-28 17:19 ` Nicholas Collin Paul de Gloucester
2015-12-29 23:37 ` darkestkhan
2016-01-05 13:52 ` brbarkstrom
2016-01-10 14:46 ` Michael Erdmann
2016-02-29 12:14 ` Jacob Sparre Andersen
2016-03-02 14:11 ` vincent.diemunsch
2016-03-02 14:23 ` J-P. Rosen
2016-03-02 15:44 ` Bob Brown
2016-03-02 16:30 ` J-P. Rosen
2016-03-02 16:36 ` Bob Brown
2016-03-02 16:52 ` Bob Brown
2016-03-02 14:32 ` Dmitry A. Kazakov
2016-03-02 15:31 ` vincent.diemunsch
2016-02-29 12:27 ` Jacob Sparre Andersen
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