[LLVMdev] Detecting reduction operations

[Chris Lattner]

On Oct 12, 2009, at 4:01 PM, Scott Ricketts wrote:

> To be more specific, it would be helpful to have some utilities for
> finding dependencies (true, output, and anti-). Where is a good place
> to start for this kind of analysis?

Hi Scott,

Do you mean loop carried dependencies?  There is some initial work on  
dependence analysis, but it is still pretty young.  We also have  
support for dependence between memory operations that are not loop  
aware.

-Chris

>
> Thanks,
> Scott
>
> On Fri, Oct 9, 2009 at 11:06 AM, Scott Ricketts <sricketts at maxentric.com 
> > wrote:
>> I want to be able to detect reduction operations using a method
>> similar to that described here:
>>
>> http://portal.acm.org/citation.cfm?id=237578.237581
>>
>> (I am open to other suggestions if there is a better technique).
>>
>> I am curious if anyone has done this with LLVM or if there are and
>> recommendations for where to start with my implementation. I am only
>> interested in identifying the reductions -- I will not need to do any
>> kind of transformation to exploit the parallelism. However, if this
>> sort of work might be useful to others, I can try to generalize the
>> interface based on any suggestions in case my work gets to the point
>> where it could be checked in.
>>
>> Scott
>>
> _______________________________________________
> LLVM Developers mailing list
> LLVMdev at cs.uiuc.edu         http://llvm.cs.uiuc.edu
> http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev