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Re: [Gomp-discuss] GOMP Requirements v1.1
From: |
Lars Segerlund |
Subject: |
Re: [Gomp-discuss] GOMP Requirements v1.1 |
Date: |
Mon, 15 Nov 2004 10:51:07 +0100 |
BIG +1 to Scott.
It's not relevant what's right, we have to come up with the goods.
As Seymore Cray once said, 'You don't have to be right, just to be fastest', (
refereing to floating point implementations, and justifying 0+ and 0- which
happend to be inequal :-) ).
/ Lars Segerlund.
On Fri, 12 Nov 2004 09:41:49 -0500
Scott Robert Ladd <address@hidden> wrote:
> Ross Towle wrote:
> > Under the Effects section is:
> > in some cases, how code is reorganized depends on the threading
> > model in use
> >
> > I have a problem with this statement and its implications.
> >
> > I very strongly believe that the outlined parallel region/work-sharing
> > region and the OpenMP runtime support routines called from the user
> > program should be EXACTLY the same no matter what threading model is
> > used. If the runtime support routines are modeled after the OpenMP
> > spec model then the threading model only affects how the support
> > routine is implimented. To me, supporting multiple thread models and
> > multiple targets is much easier by modifying the guts of the runtime
> > support routines than the changes to be made in the compiler.
>
> You may be correct.
>
> However, we're going to take a significant performance hit as compared
> to commercial compilers. Commercial vendors focus on a single threading
> model and hardware architecture; they can fine-tune their compilers for
> the vagaries of (for example) Opteron NUMA systems, accounting for
> memory architectures and processor characteristics.
>
> Perhaps I should reword the sentence to say:
>
> in some cases, how code is reorganized may depend on the target
> architecture
>
> Does that seem more sensivle?
>
> --
> Scott Robert Ladd
> site: http://www.coyotegulch.com
> blog: http://chaoticcoyote.blogspot.com
>
>
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