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From: Georg Bauhaus <bauhaus@futureapps.invalid>
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Subject: =?UTF-8?Q?Re:=20GNAT=C2=A0and=20Tasklets?=
Date: Fri, 19 Dec 2014 20:45:49 +0000 (UTC)
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"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote:
> On Fri, 19 Dec 2014 09:42:52 -0700, Brad . In image processing when doing it by
> segments, you need to sew the segments along their borders, practically in
> all algorithms. That makes parallelization far more complicated to be
> handled by such a blunt thing as parallel loop.

Conclusions drawn from one example
are fallacious here, as I am sure you
know well. Take some other algorthm like
Inverting all pixels, or anything written 
for parallel APL, or R. Anything whose
parts need not be run on a full machine
with I/O layers and active control.


> It won't, because a big number library will use the heap or a shared part
> of the stack which will require interlocking and thus will either be marked
> as "impure", so that the compiler will not try to parallelize, or else will
> make the compiler to use locks, which will effectively kill parallelism.

All the aliasing analysis explored at
SofCheck/AdaCore and considerations
regarding purity and experience gained
when developing the Spark language
based on Ada should be a good basis for
describing aspects of subprograms
that are candidates for parallel execution?