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Re: [graphite] instancewise dependence analysis functions and structures


On Tue, Aug 19, 2008 at 4:05 PM, Jack Howarth <howarth@bromo.msbb.uc.edu> wrote:
> On Tue, Aug 19, 2008 at 03:30:10PM -0500, Sebastian Pop wrote:
>>
>> Huh?  Who said so?  The fact that you see no performance improvement
>> does not mean that the code is not transformed.  It is an inefficiency
>> of the cloog-ppl port of domain_simplify function that messes up the
>> code right now.  If you want to help porting a 2000 lines code
>> function please step up ;-)
>>
>
> Sebastian,
>    I guess I misunderstood Tobias Grosser's previous comments that...
>
>> The problem seems to be that cloog-ppl does not remove all unused
>> conditions. So there remain conditions in the cloog AST and, as our
>> backend at the moment is not able to build conditions, we do not
>> generate any code.
>

Oh, sorry!  It's my misunderstanding here: yes, when there are
conditions in the transformed loop nest the graphite code generator
does not produce the transformed code.

> ...to imply that you might have the intention to fix this issue by
> adding support for the backend to build conditions rather than to
> fix cloog-ppl to remove all the unused conditions.

Yes I am trying to address as well the domain_simplify to not produce
inefficient code.

I will also include an option in the configure of GCC to make it
possible to build GCC with polylib that does not have these problems.

Sebastian


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