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From: Maxime Boissonneault <maxime.boissonneault@calculquebec.ca>
To: Rhys Ulerich <rhys.ulerich@gmail.com>
Cc: gsl-discuss@sourceware.org
Subject: Re: Adding OpenMP support for some of the GSL functions
Date: Wed, 12 Dec 2012 23:32:00 -0000	[thread overview]
Message-ID: <50C913EF.2020501@calculquebec.ca> (raw)
In-Reply-To: <CAKDqugSMk-V7Y6Dd-+aiWhew_UiJwEh3kiVRC2aAoYk+aC9qvg@mail.gmail.com>

Hi Rhys,
I will have a deeper look at vectorization of GSL, but in my 
understanding, vectorizing can only be done with simple operations, 
while algorithms like RKF45 involve about 10 operations per loop iterations.

You are correct, I meant one problem with a million degrees of freedom.

Maxime

Le 2012-12-12 16:41, Rhys Ulerich a écrit :
>> The more intensive function is within rkf45_apply in my case. I simply added
>> a few pragmas to the loops, and it speed it up quite a lot.
> Having looked at where you've placed the #pragma omp parallels, have
> you tried enabling vectorization to see if the time spent in those
> axpy-like operations could be improved?  A good SSE-ready optimizer
> should nail those.
>
> I may have misunderstood your "millions of differential equations"
> statement.  Are you rather solving one problem with a million degrees
> of freedom?
>
> - Rhys


  reply	other threads:[~2012-12-12 23:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-12-11 20:04 Maxime Boissonneault
2012-12-12 16:35 ` Frank Reininghaus
2012-12-12 21:11   ` Maxime Boissonneault
2012-12-12 21:41     ` Rhys Ulerich
2012-12-12 23:32       ` Maxime Boissonneault [this message]
2012-12-12 17:05 ` Rhys Ulerich
2012-12-12 21:13   ` Maxime Boissonneault
2012-12-12 21:36     ` Rhys Ulerich
2012-12-12 23:35       ` Maxime Boissonneault
2012-12-13  2:29         ` Rhys Ulerich
2012-12-13 13:22           ` Maxime Boissonneault
2012-12-13 15:53             ` Rhys Ulerich
2012-12-13 16:44               ` Rhys Ulerich
2012-12-13 21:07                 ` Maxime Boissonneault
2012-12-13 21:05               ` Maxime Boissonneault
2012-12-13 21:14                 ` Maxime Boissonneault

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