[LLVMdev] AESOP autoparallelizing compiler

[Hal Finkel]

----- Original Message -----
> From: "Timothy Mattausch Creech" <tcreech at umd.edu>
> To: "Sebastian Dreßler" <dressler at zib.de>
> Cc: "Aparna Kotha" <akotha at umd.edu>, llvmdev at cs.uiuc.edu
> Sent: Sunday, March 3, 2013 11:32:49 AM
> Subject: Re: [LLVMdev] AESOP autoparallelizing compiler
> 
> Hi Sebastian,
>   Sure! The bulk of LMDA was written by Aparna Kotha (CCd). It
>   computes dependences between all instructions, computes the
>   resulting direction vectors in the function, then associates them
>   all with loops.
> 
> At a high level, the dependence analysis consults with AliasAnalysis,
> and ScalarEvolution before resorting to attempting to understand the
> effective affine expressions and performing dependence tests (e.g.,
> Banerjee). If it cannot rule out a dependence, then it will
> additionally consult with an ArrayPrivatization analysis to see if
> an involved memory object can be made thread private. It is probably
> also worth mentioning that the LMDA has been written not only to
> function well with IR from source code, but also with low level IR
> from a binary to IR translator in a separate project. This has
> required new techniques specific to this problem. Aparna can provide
> more information on techniques used in our LMDA.

This sounds very interesting; thanks for sharing this with the community. I'd also like to know more about this.

Also, out of curiosity, two quick questions:

1. Why are you using the old induction-variable simplification?

2. Are you generating OpenMP runtime calls (I see some omp references in the CodeGenerationPass); if so, for what runtime?

Sincerely,
Hal

> 
> -Tim
> 
> On Sun, Mar 03, 2013 at 09:18:47AM +0100, Sebastian Dreßler wrote:
> > Hi,
> > 
> > On 03/03/2013 07:09 AM, Timothy Mattausch Creech wrote:
> > > [...]
> > > The main components of the released implementation are loop
> > > memory
> > > dependence analysis and parallel code generation using calls to
> > > POSIX
> > > threads.
> > 
> > The loop memory dependence analysis sounds very interesting to me.
> > Could
> > you provide some more information regarding its capabilities?
> > 
> > 
> > Cheers,
> > Sebastian
> > 
> > 
> > --
> > Mit freundlichen Grüßen / Kind regards
> > 
> > Sebastian Dreßler
> > 
> > Zuse Institute Berlin (ZIB)
> > Takustraße 7
> > D-14195 Berlin-Dahlem
> > Germany
> > 
> > dressler at zib.de
> > Phone: +49 30 84185-261
> > 
> > http://www.zib.de/
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